Manager Forum

Working on a 1987 Ford Thunderbird, 2.3 liter. Bucks and jerks when cold to warm. After it is warm runs great.
Have tried distributor--no luck. Any suggestions? Thanks

I WOULD TRY A TUNE UP

All new tune-up parts including an alternator. When unhook the alternator; it dosen't act up. Any other suggestions? Thanks!

Considering the alternator issue, I would scope the alternator output and look for too much ac ripple. Could be a bad diode in there.

Have tried 2 alternators.

bakerauto wrote:Have tried 2 alternators.

I've had batches of defective parts. Scoping the output is the only sure way of eliminating the possibility of it being the cause. Holmes said, "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." You have a clue there. Follow it!

Thanks!! Will try about anything right now

Also check the distributor shaft for magnetism. Had a rash of leaking alternators around here lately. Customer:"But its charging fine, it can't be the alternator."

Thanks. How do you check for magnetism? And since the cold to warm bucking/jerking happens so fast; do you think it is a cold/warm issue?

protraxrptr17 wrote:Also check the distributor shaft for magnetism. Had a rash of leaking alternators around here lately. Customer:"But its charging fine, it can't be the alternator."

How do you check for magnetism?

There is a certain data pid that you can look at but I can't remember what it is. Seems like there is a TSB on it. I would pull the distributor and simply see if attracts anything steel. Supposedly rebuilt distributors are really bad about this issue.

was the bucking there before the alternator was replaced? is it a transmission chatter? is the pressure cable on the throttle body off? take the connector off the ignition module and tweak the spades just a bit to give better contact. the issue needs to be investigated and isolated. if the issue wasn't present before the alternator was replaced and your sure there isn't a fluctuation from it (you can use a bar graph on a good multi meter) the wiring harness for the distributor is right there, look long and hard at it. the harness was probably disturbed more than a little. look for cracked insulation. if i'm remembering correctly i would un plug the module to move the harness further out of the way so it wouldn't get in my way or damaged. i have hands like feet and am not gentle.