missfire problem at idle

[gsx5104]

OK heres the deal i have a fresh rebuilt motor and the things runs bad at idle wants to die and idles really ruff. The timeing is rite there are no boost leeks or vac leeks coil pack is new and I swaped the power trans from a nother car that was running fine nonthing changed still runs bad at idle.When your driving it dose not realy have aney problems. I am thinking its the MAF .

 

[kenamond]

When you say timing is on, you mean base timing or t-belt? Many have had rough idle from being one tooth off on the intake cam. Also, on 2gs at least, the ECU might still be trying to recalibrate the ISC for idle. Might check that the ISC is working and then try adjusting the BISS to bring the idle up to spec. On a 2g, it can take quite a while for the ECU to get the idle back to spec, but it might be different on a 1g. Adjusting the BISS is a way to speed up the process...assuming that's your problem.

 

[6bolt2gdsm]

Does it still have the egr valve on it? It could be stuck open which would cause a rough idle but alrite driving conditions.

 

[rarson]

I would check the ISC and FIAV. FIAV's are notorious for causing issues. Check the VFAQs, there's a lot of stuff on idle problems, ISC, and FIAV. Just because the car doesn't idle well doesn't mean the MAF is bad.

 

[gsx5104]

the car is a 1g and i ment the timting belt. i tried to adj the biss i brought mi idle up but i mean this thing mants to die you can feel it skip and miss.The only thing i did not cheek is the egr its not hooked up but i put it back on the car to block the ports insted of making a cover. its runny rich you can smell it thats why i was thing the maf. But there is no engine light. I would not think that the iac would have aney thing to do with a skip problem as well.

 

[res7bequ]

check your firing order. My 2G had that problem after a 6 bolt swap and it ended up being swapped plugs.

 

[TALONTRAX]

I just completed a 6 bolt swap, & had a similar issue . . . turned out to be an incorrectly seated lower injector seal causing an air/intake leak on that cylinder, mimicing a misfire & also causing a lean condition . . .

 

[gsx5104]

i dont hear any vac leeks or aney thing i trid putting a little oil down on each o ring did not seam to help. when the motor is running it semms to get wors as it warms up. and the best vac i have seen on my boost gauge is 15 and i know it should be lower. And the cam timeing is dead nuts. Its a new motor and i dont want to brake it in untill the thing runs rite.

 

[TALONTRAX]

I would check for air intake/boost leaks in general as they will cause low vacuum at idle. Also do us a favor . . . run your posts through a spell checker or something man - or drink less - or more - before you post

 

[redyute1]

did a fresh rebuil and she idles like shit but u know what every time the ecu on mine gets reset from the battery being disconnected she takes a couple day for it to relearn so may be it is the same for you

 

[gsx5104]

Sorry about my spelling . The ecu is new. I did a compression test and this is what I got 110,120,150,150, now it is a fresh rebuild but I think this might be a problem. I haven't driven the car at all so I don't think the rings have a chance to set. I also blocked off the egr it made no driftnet. What kind of compression readings have others got on a rebuild? I need help I hope i dont have to rip the motor apart.

 

[gsx5104]

so i got a gm MAF and a MAF trans on the way. I think its the maf and if i am going to spend the money on a new stock one why not get the gm its way better.So after i get should be this comeing week . I will let you guys know how it went.

 

[gsx5104]

So after a long time i got to the bottom of this running like crap problem. It was the MAF the hole time. I put the gm 3.5 maf and the trans on and did a little tuneing and runs grat. You could put a glass of water on the thing.