New Engine, Jumpy Timing

Engine, ignition, fuel, cooling, exhaust

Moderators: Ranchero50, DuckRyder

Post Reply
User avatar
colnago
100% FORDified!
100% FORDified!
Posts: 1882
Joined: Tue Jun 14, 2011 8:48 pm
Location: Ridgecrest, CA

New Engine, Jumpy Timing

Post by colnago »

I got my rebuilt 352 running this weekend. I'm still doing a lot of tweaking, but it's driveable. When setting the initial timing today, the timing would hiccup a couple of degrees every few seconds. This has a new camshaft, new timing chain/gears, and new distributor. What should I be looking into? Could it be the timing light, or "crosstalk" between the spark plug cables? Something else?

Joseph
"Sugar", my 1967 Ford F250 2WD Camper Special, 352FE, Ford iron "T" Intake with 1405 Edelbrock, Duraspark II Ignition, C6 transmission, front disc brake conversion.
markguiver
New Member
New Member
Posts: 101
Joined: Thu Nov 17, 2016 5:35 pm
Location: Maysville, Ky.

Re: New Engine, Jumpy Timing

Post by markguiver »

Does the timing jump a few degrees, level off, then jump a few more or jump back and forth? If it's doing the former, I would take a look at the harmonic balancer. If I recall, you said the truck was sitting for five years prior to the engine/trans rebuild. If the rubber has dried out or is failing the metal ring could be slipping a little on its way to total failure. That would cause the timing marks to move. Something to consider.
Mark
1975 F-250 4X4 (The Beast)
1971 Bronco Sport
User avatar
colnago
100% FORDified!
100% FORDified!
Posts: 1882
Joined: Tue Jun 14, 2011 8:48 pm
Location: Ridgecrest, CA

Re: New Engine, Jumpy Timing

Post by colnago »

Hmmm, that's an interesting thought. It holds steady, then hops down, then back up to steady, then hops down, and continues like this. The harmonic balancer looked good, but everything is suspicious on a 50-year-old engine. A new balancer is only about $100 from Jegs; maybe I need to invest in a new one. I'll try to pay close attention to its behavior tomorrow.

Joseph
"Sugar", my 1967 Ford F250 2WD Camper Special, 352FE, Ford iron "T" Intake with 1405 Edelbrock, Duraspark II Ignition, C6 transmission, front disc brake conversion.
Post Reply