TIMING & RUN-ON

[Don Hagen]

FJ5, Did you ever discover what was causing your issue?

 

[FJ5 1970 440]

Exactly!

UPDATE....I through the spec book out the window and moved the timing to where the motor was happy. BOOM, no more run-on, starts great, no pops, knocks or back fires. And the car runs great. Just a little fine tuning with the vacuum advance and I'm done. I put a timing light on it and it's at about 10" or 12" ATDC. I know, doesn't make sense. I'm certain it's not a chain slip because it runs perfectly. Maybe a damper slip or a tooth off on distributor or maybe all the plug wires are clocked one hole off on the cap. I'm gonna look at the wires and cap first. Anyways, a big thanks to all you guys, couldn't have done it without you.......

 

[Righty Tighty]

Wow, 12 degrees retarded?

 

[FJ5 1970 440]

Wow, 12 degrees retarded?

Pretty sure it's a false reading.....

 

[heminut]

If the distributor is a tooth off it still won't affect it once the timing is set. Stop and think about it, if it's a tooth off and you turn it to compensate, the timing is still going to be where it would be, the distributor is just turned a few degrees off from where it would be if it was put in properly. That has no effect on what your damper is showing. I'm sure that with it running good at 10-12 degrees retarded you are going to find that the outer ring on your damper has moved.

 

[FJ5 1970 440]

If the distributor is a tooth off it still won't affect it once the timing is set. Stop and think about it, if it's a tooth off and you turn it to compensate, the timing is still going to be where it would be, the distributor is just turned a few degrees off from where it would be if it was put in properly. That has no effect on what your damper is showing. I'm sure that with it running good at 10-12 degrees retarded you are going to find that the outer ring on your damper has moved.

Gotcha, for now I'm just happy it's running great. I understand that there's a relationship between the keyway and the timing mark on the balancer, you wouldn't happen to know how many degrees that should be? Thanks again.........

 

[heminut]

Gotcha, for now I'm just happy it's running great. I understand that there's a relationship between the keyway and the timing mark on the balancer, you wouldn't happen to know how many degrees that should be? Thanks again.........

No, I couldn't begin to say, it's been a long time since I had my 340 Cuda and the 5.7 Hemi in the one I have now doesn't even have timing marks on the damper.

 

[Challenger RTA]

If it is off tooth,I believe it's 11.25 degrees. I would have to ask the tooth fairy how many teeth to be sure.

 

[FJ5 1970 440]

If it is off tooth,I believe it's 11.25 degrees. I would have to ask the tooth fairy how many teeth to be sure.

Interesting measurement, the gear on the distributor is pretty coarse, if that's what you meant, and there's a cylinder firing every 45 degrees. My head is starting to hurt. I think it's going to be a winter project/experiment.

 

[fasjac]

Interesting measurement, the gear on the distributor is pretty coarse, if that's what you meant, and there's a cylinder firing every 45 degrees. My head is starting to hurt. I think it's going to be a winter project/experiment.

If you you think it’s off a tooth, why not re- stab the distributor. And re-set the timing.
I guess if it’s running good for you then roll on.

 

[moparlee]

Gotcha, for now I'm just happy it's running great. I understand that there's a relationship between the keyway and the timing mark on the balancer, you wouldn't happen to know how many degrees that should be? Thanks again.........

Easy way to check to see if your damper has slipped. Pull #1 plug and put in a piston stop. You buy one or it is easy to make one out of an old spark plug. Rotate the crank CCW and mark the damper at the 0* timing tab mark then do the same in the CW direction. Half way between those two marks is your true TDC.

 

[Chryco Psycho]

This is exactly why I tossed my timing light decades ago & tune to what the engine wants .