Off idle stumble & while cruisin...

[y26]

I have become desperate.. This pesty off idle stumble will not go away. This all started after a tune up, Plugs, wires, fuel filter. I rechanged all those with new ones. Still no luck...

Did a search on this topic e-mailed a couple of people and tried the following.

Switched from a working car, Coil pack, IAC, TPS,MAF, CAM Sensor.
Also turned the cam sensor 1/8 counterclockwise and the car would not start so brought it back and still the same.
Also swapped ECM....

I confirmed voltage at fuel pump connector and hot wire is also working.... Everything is set according to gnttype.
TPS .44.

Also tried resetting the IAC with no luck...

So what do you guys think. What should i be paying attention to. Let me know if you need more info.

Thanks in advance for your help

 

[pracingrev1140]

what did you gap your plugs at .

 

[y26]

Tight .035.
Also used r43ts the first time then switched to cr43ts now...

 

[WE287GN]

the plugs gapped at a tight .035" ac' cr43ts

also some things of note(not sure if typical of a scanmaster??)

idle #'s in rpm not very steady,varied from like 800 up to like at least 1100,but without really hearing the difference in the motor,

on top of trying the (turn cam sensor 1/8 counter cw),we swapped in known working cap..still no change

thanks
Chris P.

 

[pracingrev1140]

have you had injectors cleaned

 

[RossGN]

Chris

I'm having the same problem with a car I have for sale. I've done all the things you have and still no luck. While this off idle stumbling is going on, I'm showing very lean on TurboLink. If I was going to keep the car, I guess injectors would be my next attempt

I may end up taking the car to a GN mechanic in Dallas tomorrow or Friday. If I do that , I'll let you know what fixed it.

 

[y26]

Yes cleaned by cody motorsport back in april of this year. I'm on another thread regarding INJ because i've heard the red stripe can be 38lb and thats what mine flowed at.

 

[WE287GN]

Hey Ross, ya he just upgraded from the stockers to the redstripes and had em flowed,seems like its not getting enough fuel according to o2's but unsure if related to the stumble problem??? stumble came in some time after injector swap.
redstripes,flowed apx 38,static fp @ 49 and can only run 15-16 lbs boost inconsistantly????on pump gas? we are new to tuning, but seems odd, stock turbo????
got us stumped

appreciate any info you may get , and we'll do the same if we get it
Chris P.

 

[WarpSpeed]

Have you checked the operation of the EGR valve? Might plug off the vac line to the valve itself, and see if it makes a difference.

 

[gnXfan]

OK - my 009s gave me the same crap. My EGR was filfthy - cleaned it and...no difference. Still a tip in and hesitation.

Testa burned me a chip - then a second one. Ideally I would have turbolink numbers to give to him to burn the perfect chip but it hasn't been necessary. His chip and a lower blm reading (ie, i turned the fueling up a bit) have solved it.

Good luck.

 

[wicked6]

Could it be a ground issue.!! Also test the coil pack with the IGN module via caspers CCCI ignition module tester! It might be the ign module. Hey ya never know. I am having a hesitation problem myself and will be going this route as my first test.

 

[WE287GN]

Thanks for all responses!!!

we havnt played with egr, something to try at this point, also going to pull and clean up some grounds see if we find anything there..

Chris P.

P.S. what about the thingy on the inner fenderwell next to map, and relay, is this not something to do with spark????

Chris

 

[Cakes]

Just for haha's I would check and make sure all clamps on intake hoses are tight and secure a full 360 degrees around the intake pipe. I had mine tight but it wasnt sealing completely and I had an off idle stumble. Hope this helps!

 

[b231v6]

Could an alternater on its way out cause this?

 

[y26]

TTT

 

[glenn c]

I feel your pain...been there done that...switched to LS-1 MAF, Translater w/extender chip, no more tip-in stumble. If you know someone with that set-up you could swap it ino your car for testing.

 

[y26]

Is this a problem that just pops up like this???
What made you switch to the ls1 MAF???

 

[glenn c]

Two reasons...Hard to find a good reman stock maf and nearly impossible to find a new maf and trying to upgrade more tuneable
with translater.

 

[charlloots]

FUEL PRESSURE
CHECK YOUR FUEL PRES AT IDLE . I HAD THE SAME PROBLEM . YOU
NEED TO ADJUST . WORKED FOR ME . GOOD LUCK
CHARLLOOTS
WE4

 

[WE287GN]

Originally posted by charlloots
FUEL PRESSURE
CHECK YOUR FUEL PRES AT IDLE . I HAD THE SAME PROBLEM . YOU
NEED TO ADJUST . WORKED FOR ME . GOOD LUCK
CHARLLOOTS
WE4

Hi Charloots, we have had pressure down to 42 static and then as far up as 47 or 49 was it steve? to try to get the thing at a base setting..
so when we startedto try and troubleshoot this stumble /hesitation, we decided to go to 45 psi static ,i believe that is what the instructions were for the JC street chip..

what was your fuel psi at when ya had troubles and where did you end up Charloots???

thanks
Chris P.