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🙁 Hi everyone. I have a 2002 Pontiac Montanna and the idle speed is driving me NUTSO! It will idle really fast sometimes and then sometimes it will idle just fine. I have replaced the IAC valve…Throttle position sensor…EGR valve…all plug wires…coil pack…spark plugs and none has made any difference. I cleaned the throttle body on the car also. There is no pattern or condition that will duplicate the problem. However, while the van is in the high idle mode, engine cold or warm, if I shut the engine down and re-start, the idle speed will be just fine. For a while. Then, with no rhyme or reason, it will start the process all over again. No codes are set. The van has 180,000 miles on it but other than that, the engine runs fine. It should…I have replaced everything but the ashtray. If anyone could help me with this problem, you have NO idea how much this will be appreciated.
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what kind of engine does it have in it? 3400 SFI? idle issues can be caused buy a hoast of things. you said there are no codes. does this include history codes? how high of a idle speed are we talking does the car have a tachometer? how random is it does it only come on once in a blue moon or does it happen frequently and intermittently?
also try this out
http://www.ericthecarguy.com/faq/solving-automotive-idle-problemsThanks for your reply. It is the infamous 4.3 liter engine. There are no history codes that I can find. The idle speed will should be about 750 rpms, but this one will go up to 2000 on an idle in nuetral. It happens quite often maybe 2-3 times a day. I am at a total loss as to what to do. I can’t afford to take it to a repair shop. Thanks again for any help.
when idle goes up have you tried tapping the gas a little bit and see if that changes things? sometimes throttle cables get stuck or stuff like that but since shutting the enigne off fixes it i don’t know if that will be the cause of the issue.
also according too some sorces the 3400 SFI 3.4L was the only avalible option for this vehicle, the Vortec 4.3L was really only used for small trucks and larger vans that didn’t require a V8
It has the 4.3 Liter V-6 engine. It is a 2002 Montana Mini van. Maybe that is listed as a small truck. I’m not sure. Thanks for reply.
neither can i and it seems kinda funny, and i cant find anything on a 4.3L v6 being in a pontiac Montana
ill look again.
take a picture of your engine if you can
i cannot find anything about a 4.3L Vortec being put in a 2002 Pontiac Montanna, the pontiac Montanna is a front wheel drive van and i can only find the 3.4L engine as a option for this vehicle, its a ransverse mounted engine and a 60 degree V6 its ignition system is 3 ignition coils that share two cylinders, the 4.3 Ecotec is not transverse mounted has a distributed ignition system, its fuel system is slightly different and its a 90 degree V6, and the only way i think it would be in your car is SERIOUS modification i don’t even think it will even bolt too the transmission in your vehicle…
what i would do beyond this point since you have no engine codes i guess is find some way too view live data with a scan tool, observe throttle position, idle air control, fuel trims, 02 sensor data. how long has it been doing this since you got this vehicle?
All that aside, I don’t recall reading where you checked for vacuum leaks. These are a big cause of idle issues as outlined in this article.
http://www.ericthecarguy.com/faq/solving-automotive-idle-problems
You might want to read through that to see if the info can help you.
Keep us posted.
Sometimes computers just get confused especially when inputs change after being off for a long period of time. For the hell of it disconnect the battery for an hour and try again.
My most humblest apologies to all who responded to my plea for help on my 2002 Montana Mini-Van.
It IS a 3.4 Liter NOT a 4.3 as I originally stated. I hope I didn’t cause anyone too much trouble. Maybe I am dislectic and don’t know it.
Anyway, I STILL need help.
Thanks, Ron :whistle:See if this helps. Try and wiggle the harness when the high idle
happens to see if the problem changes. more in this article.http://www.justanswer.com/pontiac/25fu9-pontiac-montana-2001-idling-high-speed-started-while.html
If it’s fine after a restart, that tells us that it’s likely the computer is resetting to a good state on the restart.
Which means it’s getting to a bad state some of the time. Strange that it’s not setting the CEL in that case.
As a wild guess, the computer might be losing some sensor input, like the throttle position or RPM and so it’s deciding, okay, I have no idea what is going on, let’s limp home at a slightly open throttle guess for idle fuel delivery. It will take a good scan tool to see what info the computer is getting or not getting.
Well thank you very much! I hadn’t thought of that but it is worth a try. Lord….make me fast and accurate!!!! :cheer:
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