timing belt replacement problem

Hi,

I replaced the timing belt, water pump, tensioner, and idler on my 07 Aveo5 LS. After checking everything, I cranked up the engine. It starts up right away and runs normally for 5 sec. or so. As long as it goes idling, it begins to shake and sound as if the engine is misfiring.

I checked the engine compression and they are: 188, 180, 186, 188. I also measured the air temperature sensor with an ohmmeter and it read 1.246k. This number went down when I put my fingers around the sensor and went back to 1.246K when I removed my fingers. So so far, the sensor is still working. As far as the compression PSI goes, do you think I have a timing problem?

If I press on the gas pedal, the RPM goes up and stays as long as I hold my foot on the pedal. The engine RPM needle is pointing at around 750RPM when idling. I don't know what's going on. The marks on the cam and crank shaft are still aligned dead on, as shown in the pictures.

Is it possible that the timing belt is too tight? First, I rotate the water pump to line up the pointer on the tensioner to the groove behind it. Then I slowly rotate the water pump to release the tension on the belt until the outer pointer on the tensionner lines up with the inner pointer. But after I tightened up the water pump, the outer pointer rose slightly above the inner one by 1/16 on an inch or so.

What else can I check to correct the rough idling issue?

must be off a tooth or something

No light?

It's off by a tooth. I corrected it and the engine ran smoothly. Thanks all.

hunter, your guess was correct... :wink: =D>

When you say you were off by a tooth, were they not aligned or was the belt off? What was your adjustment to fix?