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-   -   fuelcut/stutter? (https://www.nopistons.com/2nd-generation-specific-17/fuelcut-stutter-71935/)

thecrow 03-21-2009 11:27 AM

So ive been having a problem with my 86 gxl. I thought my problem was the 3800 hesitation. But im thinking its something else. So here is the problem, when i go and drive the car it only goes up to right around 3000 rpm then gets louder and has a very hard time gaining more speed/ rpm. then when i let off it backfires. The problem is only under load. it free revs very nice. when the problem happens it feels to me like a fuel cut. At one point i took off the intake and checked both primary and secondary injectors. They were both priming the system. After all this i thought it could be my ports. so i ghetto wired them open just to see if that was the problem. it was not. Grounds are good. any help would be great.

defprun 03-22-2009 09:25 AM

When I pulled the motor from my S5 it was having the same problem...

thecrow 03-22-2009 03:56 PM

do you have any idea what it is?

Nateb123 03-22-2009 04:32 PM

From the sounds of it, limp mode is your problem.

RONIN FC 03-22-2009 10:14 PM

Im not sure the S4 has limp mode capabilities.



This is a tricky one. See if your cats arent glowing red hot first.

I would then take some Vac readings, and also see if its steady.

thecrow 03-23-2009 05:19 PM

so check vacume? there is no cats. the exhaust is open right now after the manifold. so yes the ports would not be working.

defprun 03-23-2009 05:33 PM

Your ports arent working so youll run uber rich while the motor is expecting more air from the 5th/6th ports opening. If you can route exhaust to your 5th/6th port actuators youll be golden.

Nateb123 03-23-2009 05:44 PM

He said he wired them open so I discounted that as a possibility. But I agree, that's what it sounds like the problem is.

thecrow 03-23-2009 08:49 PM

yeah, when i wired them open there was no change. the only thing it changed was it wanted to die out while it was idleing. but under load no difference

j9fd3s 03-23-2009 08:58 PM

its one of two things.



1. the secondary injectors are not coming on



or the throttle position sensor is bad


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