Issues after timing belt

[davey101]

Hey guys. Been absent for a few years since my car somehow hasn't had any issues in the last few years. Decided to tackle the timing belt on it again. I've done the job four times before and feel pretty confident with it. I did go a little over kill washing and scrubbing the engine bay before hand but the car did sit for about 2 weeks in a heated garage with the battery unplugged before I started the job so I have to image things dried pretty well. Everything went pretty smooth for the most part, minus some stubborn bolts that snapped. Got the new belt and tensioner on (Bav Auto continental kit) and the timing was spot on after a few rotations. Got it all back together and fired it up and it seemed ok. Idled fine but once i gave it some throttle it had a loud whining noise from the timing area that sounded like a belt.

Decided to tear it all down again and double check everything. Everything looked normal. TDC marks still all lined up correctly. Tension seemed a little loose but tensioner was fully sprung out. Noticed the new one from the Conti kit looked a little bit different so just for haha's I put the old one back in. Made sure to rotate the engine a few times before the final tighten on the tensioner. All went back together again and starting it up it seemed quieter, however there was still some noise when giving it some throttle. I continued to bleed it out when the engine wanted to stall out and then over compensated and started idling all over the place. Quickly shut it off and let it sit for a moment. Started it back up and it idled normal but after 30 seconds or so the idle started going crazy again and the check engine light popped on and it shut off. Attempted the stomp test however I couldn't get the CEL to flash and get the codes. So I decided to stop before I caused any damage. Does anyone have any ideas? The valve train was always pretty loud before and it's certainly due for a valve adjustment...could manually turning over the engine cause an issue there? Could it be off by a single tooth? Did I mess something up electrically by washing the engine bay out? Crazy ECU relearn since it was reset? Any help would be amazing, thank you!!

[Jaxx_]

I doubt that you did damage turning over the engine by hand. You'd have to be yanking pretty hard and without care to bend anything that substantially. If your timing marks lined up, it's not likely to be an issue what so ever, unless you turned it over without tension on the belt.

The fact that the car runs OK for 30 seconds indicates to me that the problem is likely electrical or there is a vacuum leak.

Please also clarify what you mean by "I continued to bleed it out"?

I would:
0) if unconfident that you had timing correct, double check timing marks after it has run
1) inspect IAC and related components(hoses)
2) verify ignition wire sequence
3) inspect electrical connections including IAC, coolant temp sensor, AFM, throttle position, and cold start injector(if the car has it--forgive me, I don't remember if M20s had a cold start injector or not)
4) inspect vac hoses and gaskets on the intake side of the motor


You will probably find something obvious. If the car is having trouble idling it is probably something fairly significant you are overlooking. Unless you heard loud knocking or metallic sound(s), your motor is likely fine; don't worry too much.