wierd idle issues

[stoneymonk]

Hi Guys,got a strange idle issues on my 95 lumina 3.4 dohc,work done so far is sparkplugs change,pcv valve tranny oil and filter,cleaned the maf sensor.Now when i start the car the revs go up to 2000 rpms and within a second drop to 1000 rpm,and at 1000 the revs goes up and down to about 1200 back to 1000.Also after a long drive after letting the car cool down,when i go to start it does the same as above but instead of staying at 1000 rpm it does shuts off.Any ideas why.Sorry for the long post.

[robertisaar]

does it throw any codes? and that was not in the least, a long post

[stoneymonk]

does it throw any codes? and that was not in the least, a long post

Dont know i dont have a code reader,also the idiot light isnt on.Forget to mention,the last issue with the startup and shutting off problem started this weekend and happened 3 times only.

[bszopi]

How did you clean the MAF? I have heard of idle issues after people have cleaned the MAF before

[stoneymonk]

How did you clean the MAF? I have heard of idle issues after people have cleaned the MAF before

I use src sensor cleaner.

[pocket-rocket]

Good man. That stuff ain't cheap (I just bought a can for my truck), but at least it's the right stuff for the job. I've heard from people that used either brake parts cleaner or carb cleaner (can't remember which) that their sensor was fine after cleaning, but I would rather not take the chance.

[stoneymonk]

Yea it was well worth it,bought a can can last year to clean the sensors on my ford focus wagon before e-testing worked great.

[robertisaar]

carb cleaner leaves a very fine lubricant after it dries, brake cleaner is nothing at all. i would go with brake cleaner working better

[pocket-rocket]

carb cleaner leaves a very fine lubricant after it dries, brake cleaner is nothing at all. i would go with brake cleaner working better

But stuff he has is made for MAF sensors, so it would be better yet.

I like how the can says that you gain something like 4-10hp after using it. So if I clean my MAF 10 times, that's 100hp, right? It's funny how they don't mention on the can how you don't actually gain it, you just get back what you lost from a dirty MAF.

[robertisaar]

But stuff he has is made for MAF sensors, so it would be better yet.

I like how the can says that you gain something like 4-10hp after using it. So if I clean my MAF 10 times, that's 100hp, right? It's funny how they don't mention on the can how you don't actually gain it, you just get back what you lost from a dirty MAF.

moral of the story: worst case scenario: use brake cleaner

[Juglenaut]

Pull the map sensor and attempt to start does it start?, reconnect MAP and start up and pull it while running, what does the engine do? reconnect while running, what the engine do?

Pull the IAC while running, rev it up let it go to idel what does the engine do?

[stoneymonk]

Will try that juglenaut,whatam i suppose to look for?,and where is the iac located.

[robertisaar]

just yank random stuff off the TB... you'll find it sooner or later it should run up to about 3000rpm when you find it.

[stoneymonk]

Found the IAC,when disconnected the rpms went up to 3000,cant find the MAP sensor.RE and re the IAC cleaned it and throttle plate idle a little high but seems better,will know more tomorrow after a good run to work and back.

[stoneymonk]

Well after 2 days of highway driving,she seems to be idling much better and milage is good.Only problem thats still there is when its started the rpms still jump to 2000 then its goes back to around 750-1000.