Help me with a possible fuel issue?

[Invictus]

I'm pretty sure I have a low fuel pressure or some type of fuel surge issue... This is only when the car is cold, and only when I first pull out on the road.

Every morning upon startup everything seems fine. The motor cranks immediately and turns right on. No problem. I'll idle out of the driveway and immediately into first gear i'll notice it sounds a little odd, like there's no power there and it seems to hesitate; during this time the LC-1 wideband shows between 9-10! (When I had the GT it had an overheating issue, and everytime it got hot it went into limp mode and there was an extreme loss in power) That's the best way I know how to describe the symptom...

Anyhow, i'll stay out of the gas for a few seconds and slowly build up RPM then immediately I can almost feel it kick back in and all of the sudden it feels completely normal again... The wideband comes back to around 13-14.5 where it always is. The car will be fine basically for the rest of the day unless I let it sit for an extended period of time.

I cannot remember any specific mod that I did when this started, it has been doing it basically since I did the drivetrain swap. The car was well on its way to 500RWHP on the dyno but then started hesitating around 5800-6000 RPM. My tuner could not tell what the issue was and he de-tuned the car and it still made 430 with 15 degress until I figure this out...

It still has the stock pumps with the KB BAP. The only thing I can possibly think of might be the PPRV delete which I did myself... Would this be consistant with a crimped line possibly? Any ideas at all on this one?

Any help appreciated as always thanks guys! :beer:

 

[Posi]

I can't help much but before you start the car do you turn the key on and off several times to build fuel pressure in the lines? If not maybe it's that simple.

 

[Invictus]

That did not help, tried several times =/

IF I let the car idle for a few minutes upon first start up before getting on the road, it doesn't seem to do it though...

 

[TORQJNKY]

Do you have LT Headers? I have Kooks SS LT's and my car does the same thing. I always let the car warm up to where my idle A/F's come up to 14.7. My tuner told me it will do that for the first couple minutes when the headers are cold, and sure enough it does.

 

[Invictus]

Yep, I sure do... They are BBK Longtubes.

That's odd. I was hoping this issue and the high rpm hesitation issue would be the same thing. But I guess i'm glad to hear one of my problems is somewhat common!

 

[01SN8K]

The cold start issue isnt a lack of fuel. The car is flooding itself out if your wideband is reading 10. Your getting plenty of fuel, way richer than a car that is wot. Pull your plugs and see if they are slightly fouled

 

[Lil Mikey]

With the long tubes it takes longer for your O2 sensors to heat up, so that's why you need the warmup time.

As for the car having issues above 5800 RPM, did the tuner have a fuel pressure gage on the car during the pulls? If you don't have the fuel pressure cranked up in your tune then you'll run out of injector around that power/RPM level (Precise guestimate off the top of my head;-)). Also, make sure your BAP output voltage is ramping up like it is supposed to, and check for restrictions / clogged fuel filter, etc.