Modifications:

Vortech SC w/ 3.12 pulley
440cc injectors
Skunk2 plenum spacer
Walbro 255 fuel pump
UTEC

The car runs great. The only problem I have right now has been occuring over the the past two weeks. After I fill up on gas, the car cranks and cranks but does not start. It takes about 2-3 tries of extended cranking for the engine to slowly start up and sputter to life. The car will then stall. I retry cranking, give it some gas, and the car sputters to life again. I'll have to blip the throttle for about 30-45 seconds for the car to finally stabilize and hold an idle. This only happens immediately after I fill up on gas. Anytime after the car starts fine.

What do you guys think the problem may be?

 

I assume that your engine is still warm after getting gas, that you are suffering from the "dirty throttle body" syndrome that I had. Try cleaning the MAF and throttle body and see if that fixes it.

See this thread:
https://g35driver.com/forums/showthr...hlight=cleaner
and this one:
https://g35driver.com/forums/showthr...hlight=cleaner

 

I think I need to find a spot for an oil catch can then. I'll clean out the MAF sensor tonight. Weird though that this only happens after I fill up on gas.

 

Out of curiosity, have you tried just a 'warm start' to see if it behaves the same way? If it's really just after filling up, I wonder if there is some muck in your tank that gets stirred up or something and is causing fuel line restriction. . .just a thought.

Good luck!

-andrew

 

Though 440 is not that big, warm start has always been a problem with UTEC and bigger injector. Don't panic I do get them every now and then with my 440 but just blip the gas a little and you should be fine.


Edit:
I just re-read your post, can't really say anything coz I have never experience that but do you have any problem doing any Warm Start besides when tank is low?

 

I failed to mention that I did modify the fuel pump assembly per the Turbonetics instructions. Is this related?

 

anyone?

 

I occasionally have 'warm start' issues but once the car starts it runs fine, unlike what you are reporting.

The one thing that I've found that seems to help is to turn the key to the 'on' position, wait for the pump to prime (2-3 seconds) then crank the car.

Also, the lower you can make your base fuel pressure the better off you'll be. I lowered my base fuel pressure from 60psi to 50psi and all but eliminated the warm start issues.

 

just so you all know, lowering the base fuel pressure , the car will need to be retuned

 

does it do it if u drive it a while and then park it and then restart it again?

 

Nope, this only happens at the gas station after filling up the tank. I've tried filling up at different gas levels as well. above 1/4 tank, at 1/4 tank, gas light on. All with the same results.

 

bump, any more insight on this? I think it may be from too much fuel pressure. Maybe I should swap out the Walbro or get a fuel return system.