[harleynub]

So my car has a rough idle and a slight hesitation when the accellerator is pushed but it does not miss on accelleration and has plenty of power. It has new OEM plugs and wires and the coils checked out fine on a resistance test.which leads me to think fuel. I have used a couple of injector treatments with 91 octane in the fuel tank but i am not noticing any changes. Check engine light is not on, no codes so I am guessing all the sensors are good.

 

[elcompaLalo]

Have you tried cleaning the throttle body? It can definitely cause the issues you are talking about and often gets overlooked.

 

[harleynub]

Tell me if I cleaned the intake or not. I bought some Seafoam and pulled the air cleaner housing where it connects to the intake and reved up to 2000 rpm and sprayed into thr intake tract. that is how i was told to clean it.

 

[elcompaLalo]

My understanding is that in order to properly clean the throttle body, you must remove it. I don't know exactly but they usually are held in with 4 bolts. I wouldn't clean it the way you were told, any gunk or residue it might have cleaned would have nowhere to go other than the engine

.

Buy a can of throttle body cleaner, remove it from the car. Get it all cleaned up (make sure you hit it on the front and back of the plate and where it seals, you'll see) and re-install. Won't cost you more than $6 for the cleaner and its worth a shot if it will resolve the rough idle issue.

 

[goldencupkake]

I took the battery out of my car for a few days and when i put it back in the shaky idle was gone. I had been to the dealer a few times for the problem and they told me it was aging of the engine. i have driven it for a few days now and the idle problem has yet to return. IDK why the problem when away (assume its a computer problem) but it might be worth a try to disconnect your battery over night and see what happens from it.

 

[mastergutah]

I took the battery out of my car for a few days and when i put it back in the shaky idle was gone. I had been to the dealer a few times for the problem and they told me it was aging of the engine. i have driven it for a few days now and the idle problem has yet to return. IDK why the problem when away (assume its a computer problem) but it might be worth a try to disconnect your battery over night and see what happens from it.

This is great advice. Took my Malibu to a regular (non-dealer) garage. He said I needed a new PCM, but I had to go to dealer to get a new one, programmed to my car ('10 Malibu).
In the time he tested it, and looked for a short in the wires, and probably incidentally reset the PCM, and when I got it back, ($85 for 1 hr of testing- probably spent three) the problem lights were off and the car was running smoothly.

Only been 50 miles,but I am optimistic.

 

[mastergutah]

can anyone post a picture of the throttle body? I am not sure what is it- in the old days,you could see the linkage.
TIA

 

[mastergutah]

Ity has been three weeks, and still no problem. I think the mechanic basically just re-seated the connector to the PCM module, which was makin flaky connection due to oxidation, etc.