2fast4u1989

i have a lt1 6speed. i gota wawa gas (mistake) and now the motor seems to hesitate or surge/buck at me when at low rpm cruising in 5th or 6th gear. but seems fine when i got WOT. i ran that tank out and put in better shell gas and fuel cleaner but car is still doing it. what could this be? it starts fine and runs fine at WOT, but slight stumpleing at low rpm in 5th or 6th gear

SS RRR

iTrader: (2)

Any mods and have you done any work to it recently?

kinglt-1

iTrader: (26)

he said "wawa" gas lol. x2 on what ssrrr posted, need more info!

2fast4u1989

no havent worked on it recently, its stock other than a cold air and muffler delete, im putting a muffler on it again soon though

2fast4u1989

it actually seems to do it now more or so at any low rpm , not just 5th and 6th gear

gorge

take the spark plugs out and check them, check the fuel pressure, I was loosing a lot of fuel pressure and after a new fuel pump and harness found out that it has a bad injector, same thing happended to my dad's 94

2fast4u1989

whats the best way to check pressure?

kinglt-1

iTrader: (26)

fuel pressure guage hooked to the schrader valve

2fast4u1989

k, if thats the problem, how do you decide if its the pump or injectors?

kinglt-1

iTrader: (26)

if your fuel pressure is lower than spec then its your pump... sometimes a faulty regulator can cause low pressure too, but thats not the norm.

gorge

fuel pressure on my car was 33 at idle and 38 with the regulator vacuum hose unpluged, changed the pump with the harness and stayed the same way, when I checked all the plugs I found that one was soaked in fuel, so took that injector out cleaned it as much as I could, tapped it a couple of time with a wrench and the fuel pressure went up to 37 and 41 with the hose unpluged, guess my injector is staying open more time than is supposed to, so check the plugs first and then the injectors, so you dont waste 150 bucks like I did

2fast4u1989

well did at fuel pressure check, with the key turned to on and fuel pump primed its at 40psi. when the motor is on and idling its at 35 psi, does that sound ok

gorge

^^ not really, if the injection system is stock FP should be 41-47psi at idle, have you checked the spark plugs? all of them? there might be an injector staying open or just not closing fast enough

Jr.Samples

I know this is a year and a half old but have to wonder if it was ever resolved?

I have the same issue.

2fast4u1989

Hey yea it was a leaking injector. I pulled the rail up and then primed the system and two injections shot out fuel.

Tarheel'Z'

My 97 just started doing this today on my way home, was the fix new injectors? My symptoms are just as you described!
Also is it safe to say pulling the rail like you did the best way to check?