thanks for taking your time.
On 97 cavalier 2.2 there are following problems: - Engine stalls or studders on stop lights when i stop and idle. Not every time though. giving a little tap or two on a gas pedal would stabilize the engine. some times i have to keep taping till the green light.
- Couldn't start the engine after being parked for 3-4 days. I checked wires, plugs, spark was there. exhaust smelled like unburned petrol. So, ignition is ok, fuel is delivered and yet it doesn't start. Compression shouldn't be a problem, i replaced head gasket and valve rubber thingies about 8 months ago and compression was very good after repair (9.6-9.8 not too bad for 140k chevy engine). Completely puzzled i tried to start again. after so many tries it finaly started, very painfully, shaking, working erraticaly like it is completely out of timing. check engine was blinking. i shut it down. then start it again. it was a OK. check engine is on. messages P0300 and P0108. - with engine warm (i haven't tried it on cold) i rev'ed it up to approx. 4.5K rpm (in neutral) and could hear some missing. like the engine shuts off for half a second. it felt like if i rev it up any higher it would backfire.
i appreciate your response and thoughts.
P0300 is a misfire code. P0108 is a MAP sensor (Manifold Absolute Pressure). The 108 will set because of a misfire or the sensor is bad. The MAP sensor sets above and near the throttle plate. If you could borrow one from a working car or use a scanner, you could be sure.
The two codes could just be the result of any number of other problems.
Crank sensors are a pretty common problem with that engine. (near the oil filter)
The bad thing is, a lot of parts could be replaced and still not do any good.
Are you certain you timed the engine properly when you put the timing belt back on? This really sounds like an engine that is out of time.
there is no time belt, there is a chain though. when i was changing valve seals and head gasket i didn't have to take it off.
Ok - I thought all of the 2.2L 4 cylinders of that vintage used a timing belt - guess I learned something. I'm puzzled though - how did you get a head off without removing the chain? Isn't that an OHC engine?
I guess what threw me off was that my daughter had a '94 Sunbird with a 2.1L in it that was DOHC, but that motor was made in Brazil. I guess I assumed that all of the 4's were OHC.
Learnt something new again...
Difficulty starting and a rough idle after sitting for a few days sounds like something is stuck. Since it obviously jarred loose the next time you started the vehicle (but is still faulty enough to cause some misfire even at high RPM), I would check the EGR valve, first to see if it's sticking, then check if the valve and manifold port are full of soot.