James86-951

I had an unusual problem with my eng. The cam sprocket bolt backed out, killing the gear and cap/rotor. (The eng never lost timing.) I had the veh towed home and began to repair. The gear has been replaced, the key, seal, etc. The eng is timed, the comp. #'s are around 100, there is spark, and the DME relay has just been replaced.
Now I try to start it and it backfires through the intake. I am at a loss. How can I check the ign timing or reset it somehow? Tonight I will pull the cap again and make sure it is dead on one. (The cap mounts to a "dog" as defined on page 15-25 of the manual.)The keyway was walled out a little. This dmg was minimal and I don't think it would cause this problem. Back in the old days, I would say the distributor was 1-2 teeth off, or 180' out. HELP!!!

special tool

You didn't say if you took the wires off.
top right=2
bottom right=1
top left=4
bottom left=3
#1 is radiator, #4 is firewall

James86-951

I did take the wires off, but I think I put them on correctly according to the book and prev cap. That was the next item to triple check tonight.(I feel certain they are on correctly though.) I have to wait for the battery to recharge. I had been turning the engine over many times to perform various checks.

Before I replaced the DME relay, I wasn't positive the fuel pump wasn't working. I did not run a jumper to check the pump, I just replaced the relay since it was the original one. (believe it or not!)

Are there any other items that could cause this? I hope it is as simple as the wires, but nothing has moved smoothly on this car since I purchased it in August.

FSTPRSH

I just came across this. This exactly the symptoms I'm having. My car ran fine, and it acted like the key was simply turned off. I tried to start it but it keeps blowing the intake boot off the AFM. I haven't torn into it yet, been too cold. Let me know if this helps, it could save me a lot of time and dollars.

-edit-
It acts as though the exhaust valves aren't opening and the charge is being blown back through the intake.

Peckster

Those compression numbers look low. Are you sure the cam didn't slip at all?

special tool

Oh yeah, I missed the comp. numbers. Those are about 33%low. Even for a cold car, that is too low.

Dennis Wilson

Backfires are normally caused by incorrect/irratic timing or a lean fuel mixture. Recheck the cam timing, ignition timing, look for dirty/cracked distributor cap/rotor and leaking coil wire. If that checks out then check your fuel pressure.

Dennis

James86-951

I found the problem. (see: US Spec camshaft?) The rotor is aimed at #3 when the rest of the eng is at TDC. I moved the wires over by 1 position and it cranked right up.
I agree the numbers look low. I am going to give each cyl a squirt of oil and see if the rings are failing or if the head needs work.