Hi , I've got a problem with my timing beeing erattic when held at higher rpm then idle. The engine is a 440 and it's got stock electronic pick-up. I got about 10 degrees of advance and before the issues started it's all in somewhere between 1500-2000. Now, the only time that my timing seems to be stable is at idle. When held at higher rpm it bounces around a few degrees and at the same time it seems to retard timing. The higher the rpm the more it retards. At about 3000 it retards about 5 degrees and at the same time it bounces around lets say 3 degrees. What I've tried is Change Ignition coil Pick-up coil Number 1 spark plug wire The main spark plugg wire from coil to distribuor Number one spark plug Distributor cap Rotor Ecu box Tried two different timing lights None of these things made any difference. You can wiggle the reluctor slighty with the dist in the engine. Now I understand there is a little wiggle from where the shaft from the dist meets the drive slot in the engine but how much is to much?. Also there is some up and down play when grabbing reluctor and pulling. Got a video of it but but cant seem to upload it to this forum. Any ideas?
To clear things up. It does advance to about 36 at about 1500-2000. Then it starts to retard. All this while its slightly bouncing.
are you running a vacuum advance Make you a line with a T so you can put a gauge on I had a dirty carb that screwed up my vacuum
Not saying this is the problem - but had wandering timing on another brand engine and it was a very sloppy timing chain and the camshaft "walking" in and out of the block. The engine was old but it actually ran OK but performance was also pretty sluggish. Same I guess as yours - the problem only became obvious with the strobe timing light on it.
No, I've got vacuum advance disconnected. The plate where the pick-up is mounted (the one wich the vacuum advance arm pulls on is not welded in place though.
It acutally got rebuilt about two years ago. Had the dist out a few times and changed the advance springs since then. Advcanced nice and stable after last time the springs were changed. Then I just felt like checking timing a few months later and then this problem ocucurred.
I'm an old school points type of guy but don't most, if not all ecu boxes tend to retard timing at higher rpm?
Yea I guess that is a possibility. The plate feels to be quite firmly in place and it has worked without pulling timing before . But I’ll look into it
I think thats true. I’ve heard 0.5 degree per 1000 rpm is to be expected. But mine is jumping around and it’s retarding way more
On what engine is this distributor problem occurring? Did this problem just start or has it occurred since a component was changed? Is this the original/correct distributor for the engine? Are the advance springs in place? Post a pic or two of the distributor and we may have additional advice. Ron
As far as I remember nothing was changed. I just noticed it randomly checking timing . I have a couple of videos of it but can’t seem to post them here. And there is no good view into the dist. Just me wiggling the shaft back and forth and pulling up and down. I can get some pics next weekend
Lets say the springs are broken. Would that cause timing to jump around and retard? Wouldn’t that cause it to immediately go full advance and stay there?
They definitely can cause jumping around if the heavy one is Broken, kind of like fluttering if that makes sense. Did you check you timing chain like was mentioned earlier?
Thats a good question are you using a dial back timing light? I have never had good results with them
