Ok here's the issue, it's seems hard to explain but I'll attempt, the car runs great for a period but then drop face first, won't pull any kinda rpms, stutters pops and so on, sometimes I can feather the gas sometimes and it'll clear up for about 3 seconds or it won't help at all, then it comes right back, my fuel pressue gauge will hold even till this thing happens then it fluctuates by 20 psi or more stupidly fast. It's stumping me. I'll try to provide more info as I get figure out how to put it into text.

Thanks

 

Bump, need some help on this one

 

have you ever replaced the fuel pump/ filter?

 

Yes it has a new filter and the pump seems ok the screen isn't clogged but it's not a new unit by any means

 

I'm thinking it may be a bad pump, any other ideas?

 

is this a joke??? if your pump is jumping around 20 psi its toast

 

I would agree ^^ pump might be failing with the psi jumping around so much

 

The only thing that stumped me was the fact that it dosent do it consistently, will a ls1 pump work in a lt1 tank? I'll be getting one shortly

 

+1 for fuel pump

 

When you rev the motor your fuel pressure should drop a psi or 2. at idle is SHOULD be about 59.5-60psi.

I also changed the title of the thread to get more insightful people involved. "WTF is up with my car" doesnt attract most people.

 

Here's a list of possible causes of fuel pressure fluctuation like you're experiencing:

1.) Solar Flares.
2.) Cosmic Radiation.
3.) Planetary Alignment.
4.) Fuel Pump Dying.
5.) Injector Failing.

 

E. All of the above?


But seriously it could be the pump.

 

Yea the thread title in hindsight wasn't a good one, and thanks for the input everyone I figured it was a pump or injector issue but the odds of my injectors going bad at one time were nill, I'll get a pump today. Any one I should get? I'm running a lt1 pump right now

 

6.) Loose/corroded wire.

 

Walbro makes a 255 litre/hour gerotor type pump that works very well and can keep up with your future engine plans. Check the sponsors.

 

Put a new pump in, didn't do a thing to help, possibly my fuel regulator? Or perhaps vacu line ?

 

ok did a little more work on it tonight, seems like when I pull the vacuum line off my regulator the motor evens out some. it also backfires and pops out of the exhaust, lean fuel mixture. Brand new pump and filter.

 

a buddy of mine has a similar problem on his 99 truck. Replaced pump, filter and regulator and no change.

 

Not necessarily.

 

Well it's just a idea I know that's generally a cause of the backfire issue.