Fueling & Injection - Fuel pump removal question

What have you guys done it: Drop the tank the old fashion way or cut into the trunk floor?

I got the ses light on. I work for a GM dealership so i got on SI and found the diag for the codes i got (P0171 & P0174 left and right fuel bank to lean), and one of the first things it says is that the fuel pump is not suppling enough to meet engine demand. I think im going to use the Granatelli 255lph pump and upgrade the fuel rail and a set of 36lbh injectors.

Anyway back to the question. Thanx for the help

Did you bother to put a pressure gauge on? A clogged fuel filter will starve your engine.
Why do you think you need a aftermarket pump, rails and injectors on a basically stock engine? If you need a pump, do it the right way, don't hack up the car. If you don't know how to do the repair or diagnosis, pay someone to do it right. You said that you have access to SI, go re-read the diagnostics, it states that if the fuel pressure is low that the DTC will set. It also wants you make sure the O2 sensors are working correctly before it even mentions the pump. Not trying to be mean but follow the diagnostics and don't just throw parts at your car, its a lot cheaper to do it right the first time.

Trap door dumdumdum.

My car has a ton of miles and is primarily used for track duty.

The first thing you should do in your case is to change the fuel filter, clean MAF, check fuel pressure.

A dirty MAF can cause some funky codes that are hard to trouble shoot.

I vote for doing the trap door AND dropping the tank. When you go to put the pump in, you should really drop the tank so it can be properly cleaned. It gives the new pump the best chance for survival. The trap door is useful for diagnosing problems after you've re-hung the tank and you got some wires crossed somewhere along the lines.

As for cutting the trap door (although not asked), I'd recommend a simple hand nibbler. Way less messy than a Dremel/cutoff wheel, and works great on that thin sheet metal.

Another vote for the trap door. I dropped my tank twice before I just made my life easier and built a nice trap door. It looks like it could be factory and its easy.

Trap door. 10 minutes to get the pump out

Drop the tank since you have access to a lift, I did. I would further diagnose those codes and make sure it's the pump. Check your O2's and check the mass air flow sensor, seen many mass-air meters setting these codes especially when an oily K&N has been used. I also work at a GM dealership and see mass-air meters causing these codes all the time. If you think it's the mass-air, carefully remove the screen and look at the 3 elements to see if they are dirty. I have cleaned these before and fuel trims went back to normal afterwards. GM published a bulletin years ago regarding this issue with aftermarket air filters.

carefully remove the screen and look at the 3 elements to see if they are dirty..

You can't remove the screen without ruining it on a GM LS1 MAF. You can on some GM MAF's but not Stock LS1's.

Just take the four torx headed screws out remove the aluminum ends.

Did you bother to put a pressure gauge on? A clogged fuel filter will starve your engine.
Why do you think you need a aftermarket pump, rails and injectors on a basically stock engine? If you need a pump, do it the right way, don't hack up the car. If you don't know how to do the repair or diagnosis, pay someone to do it right. You said that you have access to SI, go re-read the diagnostics, it states that if the fuel pressure is low that the DTC will set. It also wants you make sure the O2 sensors are working correctly before it even mentions the pump. Not trying to be mean but follow the diagnostics and don't just throw parts at your car, its a lot cheaper to do it right the first time.

haha as a tech do you really think that i wouldnt test the fuel system first. the o2 sensors are working fine. the fuel fiter is newer. line pressure is within range. i might just do the pump cause there are other thing that need to be done first like a built trans and a torque converter.

You said you worked at a dealer, there are a lot of different jobs at a dealer. Plus it didn't sounded like you went through the diagnostics.

You said you worked at a dealer, there are a lot of different jobs at a dealer. Plus it didn't sounded like you went through the diagnostics.

yea that was my fault 69LT1Bird for not explaining very well. i did not intend to sound like a dick

Its all good, I just want people to spend money for no reason.

if both banks are real lean like 24% then check for a vaccum leak, ls1's always have that little piece of pcv hose ripped or cracked letting air leak out the throttle body, check that! thats an easy fix i have two Trans ams and its happend to both already...
<<<---also works at a chevy dealership