Rough running after head replacement Setting timing procedures?

[gregm]

I replaced a head gasket on a '95 Corolla, 1.8 engine. The car runs well when cold, but after the car warms up, the cars run well in park -- revs up high - no problems. But, when I try to drive it, it stalls out. In reverse, it seems to be ok. When I drive the car, it stalls and is hard to start -- again, the engine is strong in neutral -- but sputters under pressure. After it sits up for 10 minutes, it starts easily and runs well in park.

Any ideas as to what was not set up properly in putting the engine back together? We took off the manifolds and all connectors, etc. Any suggestions as to what I should be looking for as a problem area will be helpful.

[tashirosgt]

I haven't worked on this model Corolla, but the Service Manual for the 1996 Prizm says there is no adjustment for timing on the 1.6 and 1.8 Liter engines. The engine has a crankshaft position sensor and the computer uses this to control both the spark and the injectors. It is possible to check the timing with a timing light. It should be 10 deg before top dead center when the engine is idling at 700 rpm.

[gregm]

Thanks for the info. I checked the timing (but could not verify the RPMs -- it was likely higher than 700), and it looked to be 20 to 30 degrees advanced. Would timing that much off allow the car to run smoothly until I put it in gear?
I will clean off the connections for the crankshaft sensor to see if that helps the situation.

[tashirosgt]

You could post your question to corolland.com. Some mechanics there are familiar with crankshaft sensors.

[gregm]

I will get a tach and check the timing tomorrow -- here is an update on the engine that still puzzles me:
1. When cold, cranks immediately, drives smoothly, revs up smoothly at any rate.
2. Once it reaches normal operating temperature -- it now takes a while to crank, but it always does.
3. Sputters and stalls when driving-short distance -- no more than 1/2 block. Will with effort start, but then stalls out when I put it in a forward gear (automatic transmission). It still seems to run better when in reverse, but definitely stalls out almost immediately in a forward gear.
Any suggestions as to what I should be looking for? Many thanks.

[gregm]

I replaced a head gasket, and introduced a problem in the re-assembly. The engine ran fine before I replaced the gasket and re-assembled the head. Here are current symptons:
1. Cranks easily when cold.
2. Very difficult to crank when warm.
3. When cold, goes to 40 with no problems.
4. When warm, stalls out at about 25 mph.
I replaced the oxygen sensor and fuel filter -- neither made any difference in symptoms.

Any ideas hear? Thanks.

[gregm]

The problem turned out to be a cracked inition coil. An experienced mechanic found it -- I am surprised because the problem did not exist before removing the head,but the coil was old and a crack was clearly visible. Now, the car runs well. Thanks for your suggestions, particularly on the timing of the engine.