Small Block & Big Block Chevy Specific - Cant get my camaros engine running properly

Mainly, the car is running rich, pouring out blue smoke like CRAZY, fouling the plugs out. When it is idiling and you go to rev it up, it bogs down, and gets loaded up with fuel.

Heres the setup:

chevy SBC, it was orgionally a 327 from a 67' impala ss, it was bored, and stroked to a 355, it has 12.5:1 compression, comp cams magnum 280H (280 duration, .480 lift), Wieand xcellerator intake (it is the older, raised style), and the 492 fullie heads, a holley 650 cfm carb (i think it is a 4150, im not sure), and finally an accel HEI distrib.

The car was set up to be a race car before we got it.

Here is all of the stuff we have done to try and fix the problem:

rebuilt the carb
tried a different carb
rebuilt distrib.
changed plugs
changed power valve
vacuum checked out ok
sometimes when you unhook PVC engine RPM's will go up, sometimes car will stall (pretty sure this depends on what the timing is set at)

also, on the carb, the idle screws dont work at all, turned all the way in - car still runs fine.

im probably missing some stuff here, but i will try to answer any questions

thanks :)

edit* i did forget one thing, when you advance the timing, the car runs alot better, BUT you have to advance it so much that it wolnt start (the engine cant turn over from the compression and spark) and it constantly backfires out of the carb (which is the reason why we have changed the power valve)

edit 2* we are thinking it may be an ignition problem, but we dont want to spend a whole lot on an all new ignition and have it not fix the problem

is it a race car or street car if its a race car what are the jets in it now front and back if it has 4 jets and is a double pumper it is a 4150 type holley and you can and may have to use a power valve block off plug and squaire off the jeting all 4 the same and if the cam is real bumpy in thos cases you might have to drill all 4 throttel blades out with a small drill to add what is known as a 3rd circut to get it to behave corectly their are books in barns and nobil that explain all of this go buy one but spend the afternoon their reading till you get the right book that explains your problem than buy that one its easy if you can enjoy the read and understand it all the info you will ever need is in print hope this helps jz

is it a race car or street car if its a race car what are the jets in it now front and back if it has 4 jets and is a double pumper it is a 4150 type holley and you can and may have to use a power valve block off plug and squaire off the jeting all 4 the same and if the cam is real bumpy in thos cases you might have to drill all 4 throttel blades out with a small drill to add what is known as a 3rd circut to get it to behave corectly their are books in barns and nobil that explain all of this go buy one but spend the afternoon their reading till you get the right book that explains your problem than buy that one its easy if you can enjoy the read and understand it all the info you will ever need is in print hope this helps jz

they used it as a street/strip car

i cant remember what jets are in it, but i can tell you we put smaller jets in, and it didnt correct the problem.

It is not a double pumper, it has vacuum advance, and i have a BBC book, and it lists the same exact problem we are having, and says it is a cam timing problem... which we checked, and everything was normal

any other ideas?

ignition?

Mainly, the car is running rich, pouring out blue smoke like CRAZY, fouling the plugs out. When it is idiling and you go to rev it up, it bogs down, and gets loaded up with fuel.

You mentioned that you changed the jets, but did you set you're float level (sounds too high)? Are you're vacuum secondaries adjusted properly, because they might be opening a tad too soon. You mentioned that vacuum psi is okay, but did you check it while having a load (in gear)?

I would honestly go over everything again. Make sure you're float level is adjusted properly, secondaries are opening on time... and there are no vacuum leaks prevalent. I emphasize vacuum leaks mainly because you stated that you turned you're idle mixture screws competely closed, and it had no effect on engine idle. With the engine idling, spray a little carb cleaner by all four corners of the intake manifold, as well as the base of the carburetor. If engine RPM's speed up, you found you're leak (if it is in fact a leak)...

You mentioned that you changed the jets, but did you set you're float level (sounds too high)? Are you're vacuum secondaries adjusted properly, because they might be opening a tad too soon. You mentioned that vacuum psi is okay, but did you check it while having a load (in gear)?

I would honestly go over everything again. Make sure you're float level is adjusted properly, secondaries are opening on time... and there are no vacuum leaks prevalent. I emphasize vacuum leaks mainly because you stated that you turned you're idle mixture screws competely closed, and it had no effect on engine idle. With the engine idling, spray a little carb cleaner by all four corners of the intake manifold, as well as the base of the carburetor. If engine RPM's speed up, you found you're leak (if it is in fact a leak)...

thanks, the float level was set properly.

Not sure about the secondaries, but it is still running rick at idle, which i doubt they will be open.

Didnt check vacuum im gear, mainly because the torque converter is too small for the cam - the car stalls when put in gear, unless the idle is set really high, and the timing is advance (once again it will run like crap and backfire)

I will test for any vacuum leakes.. i know we did it before, but i dont remember the outcome.

Since the idle screws are turned in all of the way and the car is still running, doesnt that mean there has to be a vacuum leak somewhere? The car should stall.

Thanks

re check firing order 18436572 clockwise ( it doesent have points does it ? )

thanks, the float level was set properly.

Just wanted to be sure... ;)

Not sure about the secondaries, but it is still running rick at idle, which i doubt they will be open.

Early secondaries would also cause the "bog" upon throttle. Just need to eliminate this as a possible cause...

Didnt check vacuum im gear, mainly because the torque converter is too small for the cam - the car stalls when put in gear, unless the idle is set really high, and the timing is advance (once again it will run like crap and backfire)

It's stalling because it's being over fueled. Curious, what kind of fuel pump are you running?

Since the idle screws are turned in all of the way and the car is still running, doesnt that mean there has to be a vacuum leak somewhere? The car should stall.

Exactly, the engine should be changing the way it idle's, and/or coming to a complete stall. Sounds like a vacuum leak somewhere. To be honest, it sounds like a whole host of things at one time, in which you're going to need to sort through carefully...

...i have a BBC book, and it lists the same exact problem we are having, and says it is a cam timing problem.

Curious, this cam was already installed in the engine when you got it, correct? Did the original owner install it straight up, or did he install in 4 degrees advanced, or 4 degrees retarded? If you don't know, you need to check.

re check firing order 18436572 clockwise ( it doesent have points does it ? )

firing order is good :)

Just wanted to be sure... ;)



Early secondaries would also cause the "bog" upon throttle. Just need to eliminate this as a possible cause...



It's stalling because it's being over fueled. Curious, what kind of fuel pump are you running?



Exactly, the engine should be changing the way it idle's, and/or coming to a complete stall. Sounds like a vacuum leak somewhere. To be honest, it sounds like a whole host of things at one time, in which you're going to need to sort through carefully...



Curious, this cam was already installed in the engine when you got it, correct? Did the original owner install it straight up, or did he install in 4 degrees advanced, or 4 degrees retarded? If you don't know, you need to check.

im pretty sure it is stalling because either, like you said it is getting over fuled, or because the cam in the car wants a 3000 stall converter, and it has a stock converter in there (what are they, like 800?) we had it up on stands (the back wheels) and when we put it in drive, the wheels spun at probably 20mph

No idea the fuel pump, it is probably a stock-like one, i will try and see if i can get info on it, but it was painted on, so it might be hard to read.

the cam was installed straight up, we already checked :)

I have to get a battery for it, which i might get this weekend, but next time we start it up, i will check for any leaks.

Once again, thanks alot

I will try and do everything this weekend, and get back to you guys

Ok, i just checked the fuel pump, there are no numbers on it from what i can see, but when the engine is running, usually the fuel level is low in the fuel filter.

i know this doesnt help much, but this picture was taken with the engine running, and you can only see just a litttle bit of fuel at the bottom:

http://img.photobucket.com/albums/v234/victimizati0n/s80877.jpg

Ok in your first post you said blue smoke? That would be oil not fuel. Make sure your not burnning oil first
How much vac. does it pull at idle?
The reason your air fuel mixture screws dont work is because you more than likely have to have the idle screw set to high to get it to idle and your not running on the idle circuit anymore. Which is what happens most of the time with a cam with a lot of overlap.
Remove the carb turn it over. There will be a small screw that holds the secondarys open a little bit so they dont stick closed, screw it in a little at a time to open the sec. blades a little bit. This will allow a little more air in the sec side so you can back the idel screw out a little more to get it in the idel circuit.
If there is a vac leak it should run lean. A quick way to tell if its lean or rich is bring the idel up a little and close the choke slowly if the RPMs pick up its lean, if they go down its rich. If you dont have a choke then slowly choke it off with a rag, being carefull not to let it get sucked in
Another thing to check is if the bowl screws are tight Holley's are a pain to keep in tune, I would try an Edelbrock Performer carb to see if it runs better
Are you sure you used the right size intake gaskets, and what brand are they. I would stay away from Mr Gasket's gaskets. I have seen them act like a blotter and suck oil in from the valley area
One last thing where are you from?



Wade

Ok in your first post you said blue smoke? That would be oil not fuel. Make sure your not burnning oil first

were pretty sure its not burning oil.. its not the thick blue smoke, its raw fuel shooting out

How much vac. does it pull at idle?

Not sure, but i can tell you (hopefully) later when i find my vacuum gauge

The reason your air fuel mixture screws dont work is because you more than likely have to have the idle screw set to high to get it to idle and your not running on the idle circuit anymore. Which is what happens most of the time with a cam with a lot of overlap.

This is a possibility we thought of, but we have set the idle really low and they still had no effect. Is there any other way we can test them? I would like to get more info on the subject of the idle screws... thanks.

Remove the carb turn it over. There will be a small screw that holds the secondarys open a little bit so they dont stick closed, screw it in a little at a time to open the sec. blades a little bit. This will allow a little more air in the sec side so you can back the idel screw out a little more to get it in the idel circuit.

I will try this also, i have taken the carb off, but im pretty sure I didnt mess with that screw

If there is a vac leak it should run lean. A quick way to tell if its lean or rich is bring the idel up a little and close the choke slowly if the RPMs pick up its lean, if they go down its rich. If you dont have a choke then slowly choke it off with a rag, being carefull not to let it get sucked in

I just thought about this, but when i put my hands over the carb, the engine will stall, which what i would think would eliminate a vacuum leak (right?)

Another thing to check is if the bowl screws are tight Holley's are a pain to keep in tune, I would try an Edelbrock Performer carb to see if it runs better
Are you sure you used the right size intake gaskets, and what brand are they. I would stay away from Mr Gasket's gaskets. I have seen them act like a blotter and suck oil in from the valley area
One last thing where are you from?


Thanks, i tried to borrow a carb off of a friend, but he said no, i have no idea how to tune the edel's. Thanks for the note about the gaskets

Once again thanks, and im not trying to say you guys are wrong, but im just telling that we have already done a suggestion.

I will see if i can get a vacuum reading today

no problem, I know your not saying were wrong, I understand trying to find problems.
keep giving us details of what your doing, maybe something will stand out as to what the problem is
I would look for a different carb, there could be an internal leak and hard to find
If its running that rich I wouldnt keep running it to much as you could wash the rings out and dump fuel into the oil, check the oil and see if it smells like gas, if so change it. I also take and wipe the dip stick with my fingers and rub the oil between them if it dont feel slippery then it could have gas in it
keep us posted as you have me wondering what is wrong
where are you from?


Wade

after looking at the pic of the carb again. are you sure that that carb dont use the reverse idle screws, where you turn them out to lean it out, just another thought
How did you adjust the float level?


Wade

... but when the engine is running, usually the fuel level is low in the fuel filter.

If the fuel pressure seems low in the see-through filter, this doesn't help justify the possibility of the engine running too rich due to a high pressure pump. If the richness is upon start up only, then I would recommend having the setting of your choke looked at...

Back in my original post I mentioned the float level possibly being set too high, and you confirmed that it was definitely set up properly. If you still insist that she's running rich, you then need to confirm that the float is not sticking or rubbing against the side of the fuel bowl, as well as confirm that the float itself is not cracked...

no problem, I know your not saying were wrong, I understand trying to find problems.
keep giving us details of what your doing, maybe something will stand out as to what the problem is
I would look for a different carb, there could be an internal leak and hard to find
If its running that rich I wouldnt keep running it to much as you could wash the rings out and dump fuel into the oil, check the oil and see if it smells like gas, if so change it. I also take and wipe the dip stick with my fingers and rub the oil between them if it dont feel slippery then it could have gas in it
keep us posted as you have me wondering what is wrong
where are you from?


Wade

Thanks, sorry for not giving any updates, but i have been really busy lately. I tore the carb apart, and i was checking out the metering block. I got a little piece of aquarium hose, and water, and completly studied how the gas went through it. There IS a crack on the block, but when i was doing that, no bubbles came out (even if i sealed up the hole) mainly speaking, the crack stood up to my pressure. But like i said before, we tried a different carb, and the car ran the same way. Im not sure what happened with the idle screws though, i dont remember.

Theres no gas in the oil

im from PA

after looking at the pic of the carb again. are you sure that that carb dont use the reverse idle screws, where you turn them out to lean it out, just another thought
How did you adjust the float level?


Wade

No idea, do you have a list of the holley models that had reverse idle screws?


If the fuel pressure seems low in the see-through filter, this doesn't help justify the possibility of the engine running too rich due to a high pressure pump. If the richness is upon start up only, then I would recommend having the setting of your choke looked at...

Back in my original post I mentioned the float level possibly being set too high, and you confirmed that it was definitely set up properly. If you still insist that she's running rich, you then need to confirm that the float is not sticking or rubbing against the side of the fuel bowl, as well as confirm that the float itself is not cracked...

the car runs rich all of the time, not just at startup.

I will take the carb off and check the floats out. I only took a brief look at them last time i had the carb off (not very smart on my part)

You don't need to take the carb off to check the floats. Take the sight plugs out on the side of the bowls. No fuel should be coming out. Fuel level should just tickle the bottom of the hole. If you screw the idle mix screws in the car should die. If not, you are not using the idle circuit to keep the car idling. back off the idle speed screw as far as you can with out it killing (as long as your timing is set right), then adjust your fuel mixture screws. Eventually you should be adjusting with the car in drive and idling.
Hope I didn't repeat someone else......

You don't need to take the carb off to check the floats. Take the sight plugs out on the side of the bowls. No fuel should be coming out. Fuel level should just tickle the bottom of the hole. If you screw the idle mix screws in the car should die. If not, you are not using the idle circuit to keep the car idling. back off the idle speed screw as far as you can with out it killing (as long as your timing is set right), then adjust your fuel mixture screws. Eventually you should be adjusting with the car in drive and idling.
Hope I didn't repeat someone else......

i still need to check the screw for the secondaries ;)

thanks for the tips though, but the car wolnt stay in drive because of the torque converter

hey guys, im gonna take the carb and everything off tommorow... but i talked to my dad, and he said that last time he had the carb off (he was the one who tuned it) the secondaries were closed completly, and not open at all. (or he thought they were)

hey guys, i took the carb off today, and the secondaries look completly closed.

i will try opening them up a little, and testing it out, but i need to go down and get a new gasket now..

thanks, i will update everything, and hopefully that was the only problem :)

hey guys... how much do you think i should open them up?

like can i get some advice, or am i just going to have to guess and check?

The secondaries may look closed but they shouldnt be. Shine a light through them and see if any light passes by the blades. there should be a little. there is a setting to start with but I dont remember what it is. when you rebuilt the carb did you use a Holley kit or an aftermarket one. I would only use a Holley one. if I remember I think the setting for the screw is in the instructions. its like back it off till they are closed then tighten till it just contacts the blade then about a 1/4 turn, I'm not sure, but I would only go a 1/4 turn at a time to see if it helps. you will need to keep doing it till it helps if it helps
let me know what happens


Wade

hey guys... how much do you think i should open them up? like can i get some advice, or am i just going to have to guess and check?

Your going to have to do the ole trial and error method, as every engine configuration is different. You'll want to loosen them just enough until a "bog" becomes prevalent (with a load, meaning in gear), and then slowly tighten them 1/4 of a turn (while testing in between turns) until the bog is completely eliminated. Don't overtighten, as they'll then open up to late, resulting in poor acceleration. Much like float levels, and idle mixtures, they need to be just right. ;)

The secondaries aren't fully closed to help prevent binding. I beleive they're suppose to be in the 1/4-1/2 turn after the screw just touches when the butterflies are fully closed. You on the other hand are trying to introduce more are for idle. Assuming you do not have 4 corner idle.......may want to go a full turn. I'm not sure this should be all necessary on that small of a cam. How many turns are the primaries at to get this thing to idle on it's own?

ok, well, i have some bad news, i just tried, and the car is still running rich.

When i had the idle mixture screws all the way shut, it ran decent, although still rich, and when i turned them to where their suppose to be, i was flooded with smoke.

should I try opening them more, or what?

when you rebuilt the carb did you use a Holley kit or an aftermarket one. I would only use a Holley one. if I remember I think the setting for the screw is in the instructions. its like back it off till they are closed then tighten till it just contacts the blade then about a 1/4 turn, I'm not sure, but I would only go a 1/4 turn at a time to see if it helps. you will need to keep doing it till it helps if it helps
let me know what happens


Wade

the carb was rebuilt with a holley kit.

thanks

I guess if you look down the carb when it is idling and fuel is coming out of the boosters then there is a problem. The car should be idling with the idle circuit. If the throttle plates are too far open, then it gets fuel from the boosters and transition slots instead of just the idle circuit slots. If the float level is way too high it could send fuel through the transition slots and boosters, I think.

So if this is true, why won't it idle on the idle circuit? I would guess that 1:idle circuit in carb is restricted/plugged,2:there is a vacuum leak that is disrupting the vacuum signal under the carb,3:the timing is way off, 4: the valves are adjusted improperly or not seating thus disrupting the vacuum signal. You said you checked the cam alignment and it was straight up. I would have advanced it 4 degrees unless that was built into the grind.

Have you installed a vacuum gauge? what does it do? I've used a Comp Cams 280 on a 350 and did not have any issues. Long time ago, but I beleive it idled at 650 or 700 in gear. I don't think your tight stall should keep you from it idling in gear. You probably have another issue besides the carb and it is only doing what it should/would. Hope this makes sense.......

ok, well, i have some bad news, i just tried, and the car is still running rich. When i had the idle mixture screws all the way shut, it ran decent, although still rich, and when i turned them to where their suppose to be, i was flooded with smoke.

Whoa, wait a second, what are you trying to set? The instructions I gave you above were in reference to the secondaries settings, not the idle mixture. If you're trying to set idle mixture, you need to use a vacuum gauge. Hook the vacuum gauge's hose to a good vacuum source (not the port for the distributor). Turn the mixture screws all the way closed / clockwise (as per you, the engine will still be running). Monitor the vauum gauge, and slowly back out each mixture screw. Your looking to obtain the highest psi reading possible. As vacuum increases, so does idle-RPM. Lower the idle-RPM to desired setting, then repeat the process all over again until psi no longer increases.

Ultimately, you need to do this procedure in gear, but being that your stall speed is preventing this, it'll still be pretty darn close, regardless if it's in park. Now, your insisting that the engine still runs with the idle mixture screws completely closed, correct? Well, again, this would strongly point towards a vacuum leak somewhere. Here's another good test for you to perform. With the engine idling, cover the top of the carb completely with your hands. If that engine doesn't stall, you have a vacuum leak.... ;)

when you cover the carb up, the car stalls out, we have done it before, but i forgot to mention it.

also, i opened the secondaries, the only thing it seemed to do was change the tone of the engine. but like i said, when the screws were all of the way in, the car ran pretty good, and the moment they were set to normal, we were completly smoked.

timing, well, the car runs great when the timing is advanced, the plugs stay pretty clean, and theres not that much smoke.... but with the timing that far advanced, you cant rev the car up, or it backfires liek crazy, and the car will NOT start (it wolnt turn over) not mentioning backfiring through the carb. (powervalve is ok)

ill have to hook the exhaust up, and try messing with it, i dont want to piss the neighbors off to much.

should i try opening the secondaries more, or what?

could the problem also be ignition? It obvously has an aftermarket ignition (HEI) which could be crappy?

Im also thinking it is not carb related, mainly because i have tried a different carb, and the car ran the same exact way.

hope i didnt miss anything

should i try opening the secondaries more, or what?

Ahhh, now we're getting somewhere. When you cover the carb, the engine stalls.... but when you leave it uncovered, yet close the idle mixture screws, she stays running. Now your asking if you should open the secondaries more. You mean to tell me, their open while/during idle? The secondaries must be completely closed during idle, as fuel is delivered via the primaries. The secondaries open only when a certain RPM is reached (via engine vacuum, hence the term vacuum secondaries).... ;)

i thought you guys told me to open them up a little?????

they were completly closed, so i took the carb off, and opened them a little with the little screw

i thought you guys told me to open them up a little?????

they were completly closed, so i took the carb off, and opened them a little with the little screw.

Secondaries are to remain closed during idle, and open only under a load. If there open during idle, this would explain why the engine isnt stalling when the idle mixture screws are fully closed off. This would also explain why your running rich, as the metering rods linked to the secondaries are constantly remaining opened...

You might have been confusing the secondary setting with the idle mixture setting. Normally, to get an initial reading idle mixture setting.... the idle mixture screws are to be closed off, then opened back up about three turns each. Once the engine is able to idle, you can then set your idle mixture more precisely.

The secondaries on the other hand are to remain closed during idle, as well as when the engine is off. Seriously, with the engine off, and the air filter removed.... if your able to "poke" the secondary plates, lightly, with your finger, and they either open easily, or stay opened, then their too loose. They need to be closed at all times, they only open under vacuum load.

the secondaries were closed at idle before.

the secondaries were closed at idle before.

Then we're back to square one again. Take a deep breath, and review the principles of the combustion engine. An engine needs three things to run; air, fuel and spark. Aside from spark, both the air and fuel enter the engine only through the carburetor. So, if your running too rich, or too lean, chances are, it's somewhere in the carburetor. Jets, metering rods, float levels, accelerator pumps, blow out valves, secondaries, choke settings, all play key roles in AFR (air fuel ratio)...

You've already checked for possible vacuum leaks. You've already determined that the camshaft was installed correctly (straight up), and that she's timed properly. I'm assuming spark plugs and wires are good. If the float level, idle mixture, secondaries, are all set up properly, she should be pulling like a freaking raped ape. Something is being overlooked. You need to obtain a vacuum level, as well as a fuel pressure level, before we go any further.

Then we're back to square one again. Take a deep breath, and review the principles of the combustion engine. An engine needs three things to run; air, fuel and spark. Aside from spark, both the air and fuel enter the engine only through the carburetor. So, if your running too rich, or too lean, chances are, it's somewhere in the carburetor. Jets, metering rods, float levels, accelerator pumps, blow out valves, secondaries, choke settings, all play key roles in AFR (air fuel ratio)...

You've already checked for possible vacuum leaks. You've already determined that the camshaft was installed correctly (straight up), and that she's timed properly. I'm assuming spark plugs and wires are good. If the float level, idle mixture, secondaries, are all set up properly, she should be pulling like a freaking raped ape. Something is being overlooked. You need to obtain a vacuum level, as well as a fuel pressure level, before we go any further.

I will look for my vacuum gauge tommorow.

how exactly do you want me to use it? (like, give you readings at certain RPM's, or what?)

like i said, i cant have the car in gear.

how exactly do you want me to use it? (like, give you readings at certain RPM's, or what?)

like i said, i cant have the car in gear.

Don't worry about having the car in gear, as even in park, you will get a good reading. With a T-fitting, plug the vacuum gauge into a good vacuum source (again, don't use the port on the carburetor for the distributor advance. Find one with strong vacuum, use your finger by placing it over each and every port, to be sure). Obtain your psi reading, and provide the results...

Hey guys, new here. I know Vic from another forum, he has asked for my input on his problems.
I agree that there is something besides the carb wrong here. The fact that he has to advance his ignition to the point where it wont even crank points to that. I keep coming back to cam timing issues, but he has checked that.

I read thru the post and just want to say a couple things.

1) Stop looking at the secondaries.. forget them. They are not your problem.

2) The idle mixture screws can be set around 2 turns from seated and should be a good base setting until you find a vacuum gauge.

3) Pull #1 and get it to TDC

4) Pull the cap and make sure your are on #1

5) Pull both valve covers and make sure the valves are not too tight If you have hyd lifters do you know how to set them???

Start the engine and let someone keep it running by holding the pedal of the throttle under the hood. Make sure that the engine gets warm at around 1500 to 2000rpms.

6) Set your timing and post what it is set at.

7) While the engine is warm try to set your idle screw to the lowest point the engine will run at. WHAT IS THAT RPM?

8) Now that it is idling look into the primary side to see if fuel is dripping into the engine. If it is you know your problem.

I think by the time you get to #8 you will have found your problem.

My guess

1) Hyd lifters too tight
2) Carb issue with still running when mixture screws are seated.
3) Timing not set correctly.

thanks, after reading your post, i know we have done a few things, which i will update in red:

I read thru the post and just want to say a couple things.

1) Stop looking at the secondaries.. forget them. They are not your problem.

2) The idle mixture screws can be set around 2 turns from seated and should be a good base setting until you find a vacuum gauge.

3) Pull #1 and get it to TDC

4) Pull the cap and make sure your are on #1 distrib. is set fine, im 100% sure

5) Pull both valve covers and make sure the valves are not too tight If you have hyd lifters do you know how to set them??? when we checked the cam, we also adjusted all of the rockers

Start the engine and let someone keep it running by holding the pedal of the throttle under the hood. Make sure that the engine gets warm at around 1500 to 2000rpms.

6) Set your timing and post what it is set at.

7) While the engine is warm try to set your idle screw to the lowest point the engine will run at. WHAT IS THAT RPM? i assume you mean keep turning it untill it stalls, and give you the RPM, sometimes you can set it too low, and 5 or so min later it will stall

8) Now that it is idling look into the primary side to see if fuel is dripping into the engine. If it is you know your problem.

I think by the time you get to #8 you will have found your problem.

My guess

1) Hyd lifters too tight
2) Carb issue with still running when mixture screws are seated.
3) Timing not set correctly.

i will do the other stuff you mentioned, and i will post back.

Dumb question: I assume your distributer is vacuum advance? Make sure the vacuum line is attached to carb vacuum, and not manifold vacuum.

Dumb question: I assume your distributer is vacuum advance? Make sure the vacuum line is attached to carb vacuum, and not manifold vacuum.


yes, the distrib is vacuum advance, and it isnt a stupid question at all :)

it is def. attached to the carb, because i almost forgot to put it back on after I reinstalled the carb

hey guys, my dad just called me up about the car, and he said he was reading some stuff, and it could be that the fuel pump is bad, or its pumping too much gas into the carb.

i got to thinking, but is this possible? if this were true, gas would be squirting everywhere, and wouldnt gas be flowing out of the float screws?

sorry for not updating this, but we tried starting the car a few days ago, and it wouldnt run at all... so im gonna take the carb off, and close the secondaries up.

My dad also mentioned that he did turn the idle all the way down, to just before the car would stall, and it would still run rich. Obvously it is bypassing the idle circuit in the carb... but wouldnt that be a vacuum problem, or an internal carb problem?

or could it be that it is getting too much gas from the fuel pump, and it is stalling the car out even though it can idle lower?

From what i remember, it will stall under 800 or so RPM

ok, i have a few updates...

checked the fuel pressure, and it is 6 PSI

i totally forgot to check the carb vacuum (ugh) but when i took the carb off to close the secondries i saw a vacuum line on the back of the manifold was all butchered up by the previous owners. (a random line with a screw in it, and a plumbing piece with a bolt jammed in it) anyways, i fixed that.

my dad came home, and messed with the timing, so i have no idea if what i fixed made it not as rich, or him changing the timing, but we didnt get smoked out as bad as usuall.

the idle mixture screws did have some effect, but they were still turned all the way in, and the car stayed running.

i may off track here,[if so forgive me.] when i changed distributors in my 71 z28 i had similar problems. are you sure that your dist. isn't off a tooth. that was my problem. holley carbs on a small block auto. chevy are tough to make idle right, when you get it solved let us know. good luck.