i took my 87 gn to the track it ran fine, ran a 11.67 on 16 pounds everythng was good.then 2 days later the car loses fuel pressure underload (anything over a quarter throttle) parks in neutral and rev up cleans. so i replaces my regulator had a bosch and changed to a accufab, few days later had a racetronix 340 pump and changed it to an aeromotive stealth 340. and still dong the same thing. once you gas it (even a little it leans out) it leans out to like 22:1 it feels like the turbo is sneezing, lean pops, stumbles and bogs. also the cars on e85 and 60 pound injectors ran fine before. No idea whats going on!
Need help! located in OKC
- Thread starter g1985n
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John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
- Messages
- 5,002
Internal leak on the connector hose at the pump hanger? Had this happen to me. They can crack and you lose fuel pressure at anything over idle.
You don't know if you have a fuel delivery problem until you monitor fuel pressure. You need a gauge with these cars. The other thing is that you probably have too much fuel pressure at an idle because of that new pump you installed. It overwhelms the return line causing high fuel pressure at an idle and low speed operation. Bigger isn't necessarily better. GAUGE!
its 44 psi at idle with the vaccum off the regulator and drops like a rock, anything over 1/8 or a 1/4 throttle using a snap on gauge it dropped to 15psi
Man,I guess we can say you have a fuel delivery problem. Have you changed the filter recently?Does the pressure drop when you reconnect the hose to the regulator?
Yes brand new filter from a local performance shop. And yes it drops to like 33psi
Today i replaced the connector hose.. it helped some i can feel a difference. im wondering are my injecters to small or my o2 sensor is going bad.. before it was hard to go from a stop just to catch a little speed i would have to adjust my foot to keep the air/fuel to stay withing limits, i would have to ease into it nice and slow. what should my fel pressure be set at with vacuum? right now its at 43 psi i heard on e85 i should set it on 50psi seems a little high.? heres a little about my car if it helps im a newbie. 3.8 bored .30 over 60 pound injectors60mm precision turbo .63 housing full front mount intercooler vigilante 3200 stock heads ported with larger valves 212 cam turbo tweak e85 chip.Any one know of a tracy hooper in okc? im wantingto get in contact with him. thanks everyone!
You said fuel pressure was falling. Does it still?
did you have this problem before you changed the fuel filter?
John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
- Messages
- 5,002
Do you have a volt meter so you could check voltage at the fuel pump? You'd need some wire to tap into the pump connector then run up to the driver seat so you can watch voltage under load. Even if you just power braked in the driveway that should be enough to test for full voltage at say 3000 - 4000 rpms.
yes
no
yes i forgot to mention i did that yesterday under a load it stayed above 13 volts the whole time.
it was working fine one day and i got home parked it for an 1 hour, got back in and a camaro pulled up and thats when it started acting up, and ever since then thats the way is been for about two in a half weeks . the guy i bought it from replaced the pump hangar wen i bought it from him. thats the last thing.
I think it would be worth another filter change. AC delco only. If your fuel pressure isn't rising,we need to fix this as this is a major problem. Are your injectors to small? Perhaps,but that is something you can determine after you correct your fuel supply issue.
ill go ahead an change it today and see what happens, hope the tornados stay away!!!
Amen!
No. Does your filter have a replaceable cartridge? If it does,you could first test it without the cartridge. You wouldn't want to do this if you find a lot of crap inside the housing.
sorry for not checking up, had a long weekend! Found the problem yes it was the fuel filter. i guess it wasnt getting the right flow. Took it cruising over the weekend, the only thing is it feels like i lost power =((. but oh well thats another problem, probably needs to be tuned or something. What psi do you adjust your fuel pressure to?
