Runs Rough after Distributor Swap (Page 2/2)
CookesForChrist OCT 27, 09:23 PM
Yes, the jumper was in place when I set the timing.
Patrick OCT 27, 09:49 PM
Next step then is determining if the outer ring of the harmonic balancer might've spun on the inner hub... as if it has, the ignition timing will be all off. This is not an uncommon occurrence.

The main timing mark needs to line up with the actual TDC of cylinder #1.

[This message has been edited by Patrick (edited 10-27-2019).]

CookesForChrist OCT 28, 11:37 AM
This morning, I decided to try (gently, slowly) rotating the distributor while the car was running normally (not in diagnostic mode) while I listened carefully to the engine. With my ear I could hear what sounded like a more optimal position. At that point, I put the computer in diagnostic mode and then got out my timing light. I could see that I was now on the right track. What I had previously thought was the timing groove was obviously some other mark on the balancer. NOW I could see a very obvious, noticeable groove all along the edge of the balancer, and it was lining up closer to where it should (around 14 degrees). I rotated the distributor a touch more, and I was at the 10 degree mark (more or less).

I guess that the timing had been SO far off before that I couldn't even see the right groove!

I then exited diagnostic mode and took the car for a good long spin on the highway. It never drove better! At idle, the RPMs fluctuate only from 900 to 1,000. No roughness at all. It was simply a timing issue - or more honestly, a human error issue.

Thank you, gents. Problem solved! God Bless.

David

[This message has been edited by CookesForChrist (edited 10-28-2019).]

fierosound OCT 28, 11:40 AM
for solving the problem. Persistence pays.
Patrick OCT 28, 01:03 PM

quote
Originally posted by CookesForChrist:

What I had previously thought was the timing groove was obviously some other mark on the balancer. NOW I could see a very obvious, noticeable groove all along the edge of the balancer...



There are three timing grooves/marks on the balancer. Two narrow ones and a wider one for cylinders 1 & 4. If you had used one of the narrow grooves for your ignition timing, I doubt the engine would even run... unless the outer ring of the balancer has spun, thus negating all efforts to correctly time the ignition with a timing light.


quote
Originally posted by Patrick:

Next step then is determining if the outer ring of the harmonic balancer might've spun on the inner hub... as if it has, the ignition timing will be all off. This is not an uncommon occurrence.

The main timing mark needs to line up with the actual TDC of cylinder #1.