Could too much fuel pressure cause my car too idel up to 1500 for a few seconds then come back to normal.It dose this everytime i start it cold hot it dosent matter and everytime i come to a stop.Like at a red light it idels up to 1500 and is hard to hold but after a few seconds it will idel perfect agin.Iv swapped out the iac with 3 diff ones i had but always the same.Any ideas???

 

no one has ever had a high idel problem i guess.Iv searched and found nothing on high idel always low and that has me kinda worried lol im guessing since this isnt a commom problem its probly my ecm.Im also having a tcc lock up problem too which im hopeing its all in the ecm i just hope its the ecm itself and not the chip.

 

i also have same issue, when its in gear it jerks and wants to stall when at a light, i put it in neutral and the motor idles up and down, i havent come to a solution yet, i did a full tune up, this mechanic suggests that i do a flush of the tpi and injectors, was gonna try that, only other thingi can think of is i got a bad injector

 

maf sensor

 

its brand new

 

the flucuating idle would have to be the iac, maf, or ecm i would think. try unpluging the iac and maf and try that. Are there any codes being triggered?

 

I had a similar problem. Check your TPS and IAC first. Then measure the resistance of your injectors. I just put in the Bosch III and it was night and day difference. I had checked all the basic stuff first but in the end it turned out to be my injectors.

 

No codes. Well my maf is new and my injectors are new venom 21 lbs iv tryed 3 different iac all act exactly the same.I rebuilt my motor all new but cam and lifters which im going to get a new set up comp 268XFI this income tax time lol with a set of new afr 1041 heads.But anyways, I ran it a while then I got a new maf,injectors,1.6roller rockers,headers put all that stuff on and it ran good no problems.Then recently i ported my plenum and runners and when i put it back together i had this problem.I also noticed last night when i started it cold that it starts better cols than hot.It dosent rev up to 15 cold just about 11 like it should,baiscally starts and runs perfect cold just like it always did no change or problems at all there.Just when it warms up to operating temp is when it starts ideling to 15 for a few seconds when i start it or come to a stop.Its just like the iac is lazy way lazy but would 3 of them all act exactly the same?seeing as how my tcc isnt acting right the only thing im left with is the ecm.I checked the tcc to see if it was locking in 2nd and its not.I dont mind replacing the ecm i just hope its that and not the chip memcal prom or whatever its called iv heard all 3 used so thats why i just say chip lol.The ecm thats in it says gm factory authorized remanufactured so im guessing the previous owner must have had to replace it for somereson unless gm used some like that.Any more input would help thanks.Oh yea im thinking of either buying or letting someone hook it up to a scan tool and see what the ecm is seeing thats probly the next best step I should take.....Sorry