RedLS1Iroc

currently im running the stock fuel pump from my 87 iroc to my ls1. the car has ran flawlessly over the past two years but recently its been having some problems. it will run just fine at idle and even for a couple of minutes while driving but then it boggs down really bad and i have to do everything i can to keep it running. then i can shut it off and it will start right up and repeat the sequence. im wondering if this has anything to do with fuel delivery or if it could be something else. any suggestions would be greatly appreciated.

V8Rumble

iTrader: (9)

Hmmm. We can't yet tell if that's the cause of your problem or not, but it's sure as heck not helping... Have you performed any diagnostics yet? (Checked for codes, checked fuel pressure, etc.)

If not, that's where you'd start, but you're going to want to plan on installing a better fuel pump eventually...

ls1nova71

iTrader: (4)

I have 128,000 miles on my swap, been running for 8 1/2 years on a stock AC Delco fuel pump for a TPI IROC Camaro, I've never had any problems with it. (Did I just jinx myself?) But, your pump may be getting weak, or maybe you need a new filter?? What's your fuel pressure?

V8Rumble

iTrader: (9)

Hmmm. Interesting. Unless I've mis-read things, it seems to be a given on TGO that the stock fuel pump just isn't up to the task... Apparently some have better luck/results than others...

Heh - could be...

Yeah, my 1st thought was that the pump was getting weak, but the filter idea is a good one too. Regardless, it's all just guess-work until some diags are done...

bczee

iTrader: (12)

Try putting a Fuel Pressure gauge on the fuel rail and watch it. That will put an end to the fuel pressure/filter questions.. If its leak or low.. then check out the pump and filter.

Have you checked all of your Vacuum, PCV and other sources that could cause a vacuum leak ?

ls1nova71

iTrader: (4)

Speaking of leaks, I have also had the small hose that connects the fuel pump to the sending unit in the tank get a small hole in it, and it would allow the engine to run, but would bog down when you gave it any throttle at all, and since it was in the tank, you couldn't see it leaking.

So yeah, more diagnosing is in order.

RedLS1Iroc

thanks for the suggestions. i guess im gonna start by checking the vac line, if i dont find anything ill get a diagnostics check. i did recently replace the fuel filter so i dont think thats the issue

crainholio

iTrader: (2)

Sounds like it runs fine while the PCM is in open loop mode, then the troubles start when closed loop is set.

Usually this is caused by bad O2 sensor(s) or a bad MAF.

Scantool needed, unless you just want to throw parts at it.

When you have a scantool connected, do this:

1.) Check and report any stored codes.
2.) Check and report LTFT percentages for both banks.