Idle problem

Archived topics from the Diagnostic Help Forum
Guest

Idle problem

Postby Guest » Sun Feb 23, 2003 6:43 pm

Here is the scenario:
i bought this 1989 GT automatic V6 about a week ago. It has only 44,000 original KM. This guys grandpa bought it brandnew and only drove it once a week to town and back. He kept up with oil changes and that stuff. he replaced the ECM 2 years ago, alternator and battery a year ago, and exhaust was replaced 2 years ago.

OK with that out of the way, it has been running good until last night. After driving for about 10 min on the highway, i parked and shut off the car. I went to start it after about 3-5 minutes and it would almost start... it would turn over and start but instantly shut off, it would start to give it gas and it would choke. I tried 3 times and the same thing every time. So i gave it a little gas when starting and it started the 4th time. And started every time after that, i drove it and stopped shut it off and started it about 10 times no problem. I even went and got gas so the car was off for about 7-8 minutes and it started no problem.

Everything seems fine, but when i stop at stop lights the car lights and dash dim, and the car seems to choke, not die, and then seems to give itself a shot of gas or something and the RPMs shoot up and keep the car going then the RPM's level off but the car is idling at pretty low RPM and everything stays pretty dim. When i first start the car and press and hold the brake and then put it into drive the idle stays fine and nothing dims but as soon as a i drive even two feet and then brake the car does the same thing.

The SES light comes on normally when you start and then shuts off normally.

I just installed a new CD deck(two days ago)in which i disconnected the battery, i did not relearn the idle yet as i was just reading about it today, i will do it after i finish this. But the reason i dont think that this is it is that the day i finished installing the deck i took it for a drive for about 15-20 minutes and didnt experience this.

I think maybe because it was underused for most of its life that maybe a few things have clogged up?

ALSo...theres more....
i dont know if i should start another topic or not but..

My oil pressure seems to fluxuate quite abit. When i start it the pressure is at about 3/4 (i have a digital dash so i dont know the actual readings) and then i drive it for a while it will remain between 1/2 and 3/4. but when i am idling it goes down to 1/4, the when i start going again it jumps up to between 1/2 and 3/4.  IS THIS NORMAL????

I am not a mechanic as you can problably tell from my post, so any help would be greatly appreciated







Guest

Idle problem

Postby Guest » Mon Feb 24, 2003 2:19 am

So i reset the idle.
After I reset the idle i started the car and the RPM shot up to 3000 and then leveled off right away around a 1000

So i drove into the nearby town and came to a stop at the stop sign, and when i come to a complete stop the RPM dropped to 540, for justa second then jumps up between 640 and 700, still running a little low (lights and dash are still a little dimmed.) This only happens (drop in RPM) the second the car comes to a complete stop

I am probaby gonna take it in to a GM mechanic, but i dont want to if i dont have to and i dont want to get ripped off if i have to

PLEASE help



Guest

Idle problem

Postby Guest » Mon Feb 24, 2003 3:47 pm

mine does that when i havent started it in a while, i'll go and start it, it'll fire up then it'll stall. only way i can keep it going is if i give it a little gas. but mine has almost 200k miles on it



Guest

Idle problem

Postby Guest » Wed Feb 26, 2003 2:49 am

So today the idle seemed to return to almost normal. When i come to a complete stop the RPM only drops from 800 to between 640 and 720. still pretty low, but it doesnt seem like it is going to stall. Hopefully it will continue to 'fix itself'
the oil pressure is still bouncing up and down alot. What i have been reading is that it could be the sending unit or normal behavior i guess. I am still getting it checked out tomorrow just to be sure



Guest

Idle problem

Postby Guest » Mon Mar 10, 2003 5:17 pm

the oil pressure is normal for gm cars to drop like that.  My 91 GT does that all the time, especially when you go on long trips.  It'll ride about half all the way until you slow down, and then it'll drop just like you said to about a 1/4.  That is normal.



Guest

Idle problem

Postby Guest » Mon Mar 10, 2003 5:29 pm

Sounds like the fuel pump is getting ready to check out. Mine did this for 4000 miles then I realized what was up, and changed it. Never had another problem with it and eventually sold it.



Guest

Idle problem

Postby Guest » Mon Mar 10, 2003 8:30 pm

hey beretta nick..
you think speeding in a school zone is funny? Your a sick pup, dude.
Bud:(




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