Having a problem with a LS1

[BAD RAT]

I have a 36 chev with a 02 LS1 completely stock motor in it,, the ECM and engine wireing was reworked by Street & Performance;; it has a Tanks fuel tank with the in take fuel pump,,

the problem is They car has ran like a top eversince it was finished a few years ago,, not alot of miles, but ran good,

just recently it has been acting up hard to start, sputters and guits running, no power under throttle [ it won't hardly untrack itself,, ] runs really rich sometimes it runs pretty good then decides to act up again,, but now its decided to not run hardly at all,,

I checked the plugs,, look good ;; checked the fuel pressure,, at the fuel rail was 12 -15 # ? [I thought it was suspose to be higher, like 30 #] checked the wiring on the throttle body Ok, air temp sensor hooked up to K&N filter, maf was clean and wireing ok,,

I am definately not a fuel injection mechanic, or know much about them,, just a real PITA when they don't run right,,

I assume the reason it is running RICH has something wrong with the T-body or incoming air control..??????

Any ideas guys Please??? Thanks bill

[kennyd]

fuel pressure should be 40-45 psi , it will still start with less but it will not take any throttle . i know tanks makes a great tank , but what pump did they use ? i have had problems with the gm style rail pump .

[MRJB1929]

Rent or borrow a good ODBCII scanner / engine diagnostics. Hook it up and run it while driving. It's best to have someone drive as the other is monitoring the scanner. It will tell you a ton of what is going on with the car.

Yes, fuel pressure while running should be well above 30 PSI - if not, check filter, pump, regulator for problems. Your problem does sound like fuel pressure.
Jerome

[green34ford]

I have a 90 corvette that sits more than now than it use to that started idling
rough. once you gave it some gas didn't seem to be any problems . I had three
injectors that were not working at all. they make a tool now my buddy has one
all you do is have the thing running and point it to each injector and it will tell you if its working. He told me need to drive it to keep things working.
good luck

[Mike52]

Bill, an LS engine needs 58 psi fuel pressure to run properly, you don't have enough. I believe Tanks uses a Walbro pump. For a wealth of information about the LS engines, swaps, etc, check out LS1Tech.com

Mike

[BAD RAT]

Thanks a bunch guys,, I checked out everthing as far as connections, etc,, pulled the fuel filter,, and it was clear, I intend to pull the pump and reg, today and replace both,, regardless,, don't want to have to take that tank down more than once,, it was installed when the body was off the frame,, but made it so the tank could be removed, but no way is it easy,, especally with a 3/4 tank of gas in it,, What a PITA,,

should just roll it out in the street and put a FREE sign on it,

[BAD RAT]

Bill, an LS engine needs 58 psi fuel pressure to run properly, you don't have enough. I believe Tanks uses a Walbro pump. For a wealth of information about the LS engines, swaps, etc, checl out LS1Tech.com

Mike

Thanks Mike,, I did check out LS1Tech,, lots of infro there,, rather interesting bunch also,, some good ideas floating around there,,

[Mike52]

Bill, I've dropped an LS1 in the '32 I'm building, that site has been a huge help for me!!! I hope you get your problems straightened out soon.

Mike

[glennsexton]

Hey Bill - let me know if you roll it out on the street - I'll come buy and take it off your hands!!

Sound's like the fuel pressure's too low. New pump and regulator and I'm hopin' that bad boy will run fine!

Regards,
Glenn

[BAD RAT]

Well I found the problem,, instead of dropping the tank , I cut a access hole in the trunk floor above the pump location,, just happens to be directly below the battery location,

I tested the pump pressure right at the pump,, it was about 12 #,, so that told me that the pump was bad,, I pulled the pump out of the tank,, to go get a new one and while taking the short rubber hose that goes from the pump to the outlet fitting, I noticed it was split,, so it was pumping but squrting back into the tank,, so that meant that something caused it to build enough pressure to split that hose,, The 2 rubber hoses for supply and return were flattened a little from being mashed between the tank and floor of the car,, just enough to cause pressure to build up enough to rupture that hose , [ the tank was installed before the body was , ]
at least now I don't have to buy a new pump,,

Hey Glenn,, You probably wouldn't want this thing,, its just a old 4 dr , Chev

[Mike52]

Glad you found the problem and also glad it was an easy, cheap fix.

Mike