99 Grand AM 4Cyl, engine vibration at idle

[ViruZR1]

Hi,
Ok my car runs perfect, and the engine is really quiet when im driving
BUT when i get to a stop the engine starts to vibrate realy bad, the idle is 600rpm when its stop which to me is kind of low but im not sure if thats the normal idel to this car. OK when i start to move from a death stop if i accelerate to slowly the car kinda wants to turn off(well it was turnoff like twice but not all the times) i dont think its a spark problem cus if i really step on it the car just goes with no bugs or nothing the only problem is at the idle or when im driving like at 5-10mph it kinda want to die.
Oh btw there is no Check Engine light or nothing like that.

[rosaritomanny]

just a quick thought, whens the last time you changed out your fuel filter. that might possibly be the issue. I had one guy come to me with a 99 sunfire that kept stalling when he was driving. I changed the fuel filter and that soved the problem

[ViruZR1]

Hmm that sounds like a good idea Im gonna do that!
I have never change the fuel filter in this car and i have had this car for like over 2 years.
Thx rosaritomanny

[ViruZR1]

I change the fuel filter but that didnt fix the problem it still shaking alot
Anyone have any ideas?

[3100]

Check your vacuum lines. Listen for air leaking sounds.

[ViruZR1]

It finally give me a Check Engine Light, i was thinking it could be the TPS but I took it get it check and it said it was the MAP Sensor but its $70 so i have to wait until i get pay.

[3100]

You can test your MAP at idle it should produce about 1.3-1.5 V depending on how good your engine is. If you see more than 1.5v you have vacuum leak somewhere so check your vacuum lines again and make sure sensor wires are in good shape.

[SteVB]

have your MOTOR MOUNTS & TRANSMISSION MOUNTS checked for the vibration at idle with the car in gear & your foot on the brake.
i bet that`s what it`s going to be.
have someone watch the engine with the hood up ,and with it in gear & your foot on the brake firmly, give it the gas about an inch down on the pedal then let off the gas quickly, then do the same thing in reverse. if they see the engine jump up then drop back down when you let off the gas, you have a bad mount or possible more than one bad mount.

[3100]

Originally Posted by SteVB

have your MOTOR MOUNTS & TRANSMISSION MOUNTS checked for the vibration at idle with the car in gear & your foot on the brake.
i bet that`s what it`s going to be.
have someone watch the engine with the hood up ,and with it in gear & your foot on the brake firmly, give it the gas about an inch down on the pedal then let off the gas quickly, then do the same thing in reverse. if they see the engine jump up then drop back down when you let off the gas, you have a bad mount or possible more than one bad mount.

bad engine mount will not turn off the engine

[3100]

I told you you have problems with vacuum lines somewhere or vacuum leak

2-3 days later you came here and post that that you have check engine light and that it was map code so I was right focus on vacuum forget mechanical parts now. Do the thest that I told you measure map sensor voltage at idle. tell us what you got. good luck

[xeroinfinity]

Here is the procedure, with pics, for the MAP sensor..
http://www.automotiveforums.com/vbul...d.php?t=665979

But I would agree with SteVB, have your engine mounts checked too. Usualy the problem with shaking while idling. Could have more then one problem going on.

[ViruZR1]

Thx for all the Help! and yes one of the problems was a vacuum leak well kinda!
it was the hose that goes from the MAP to the intake manifold it was kinda melted and really close so almost no air was passing thru it.
I had the car ON and then i was looking at all the hoses then i saw it and as soon as i touch it the car turn off! so i got a new one and the turning off is now fix!
But it still vibrates when im stop BUT not as bad as before, i still need to check the MOUNTS. Thats the next thing im gonna do, and i will come here and update!
Thx Guys!