Mechanics

IDLING ISSUE WHEN STARTING UP WITH BOUNCING AROUND AND SHAKING.

1999 Pontiac Grand Am • 268,000 miles

I have a 99 Grand Am having about 270k on it. It has run great over the years with minor problems. In the past few weeks I have noticed that when I turn my car on after not being on for awhile it has a hard time idling and I can watch the RPMS drop really low like its going to stall out (it is an automatic BTW).

Anyway, It chugs and for the first few hundred meters of driving its rough bouncing around a bit and then tends to smooth out no problem. Today however I noticed that it started knocking in the engine so I checked the oil and its really low all of a sudden which I am assuming is causing the knocking. I am wondering if the starting and idling issue is related to the oil. This car does not get driven around very much as we have another car we usually drive.

BTW, when its having the problem idling at start-up, giving it gas seems to stop it at that very moment from shaking but it immediately starts again, it will only smooth out if you physically drive it somewhere.

Fuel pump has been replaced
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Danridgeway
August 6, 2012.



Scan for codes, and check fuel pressure. Clean throttle plate with choke cleaner or throttle cleaner as well as iac valve hole-it's kind of oblong. Clean plateon both sides they ge gumy and cause this.

Hmac300
Aug 6, 2012.
Would this gummy stuff account for the car actually shutting of a few times while having the idling problem? It made a big bang one time that I didn't start driving one time and the RPM'S dropped too low so it went "Bang" and shut off. I turned it on a few seconds later and the car was fine. Not chugging.

Tiny
Danridgeway
Aug 6, 2012.
It could, normally when you come down to an idle from driving the car stalls like at a light. The bang you heard could have been anything. Try what I said andsee if it's okthen

Hmac300
Aug 6, 2012.
I will try later today when I get home, Thanks!

Tiny
Danridgeway
Aug 6, 2012.