took out the car today...thanksgiving, 60°, sunny, ideal conditions...started it up, let it run for a few minutes, then took off...ran well in 1st and 2nd gear, once we got into 3rd gear, and 30mph and up, it jumped alot. It felt like it was severely pulling forward and backwards, didnt better/worsen for the few miles we went out. Under 30mph it seemed fine.

What can this be? Has this happened to anyone here? thanks in advance. -JON ('74 1.8, stock FI)

throttle switch unpluged? Trigger points?

Is it DJet? LJet? I think on the Djet the throttle position sensor gets gummed up right around the position you do most of your cruising in. on LJet the signal is actually the flap position but the same basic thing happens. You can try to clean it with contact cleaner but often it requires replacement or rebuilding...

I've found that most TPS's ( about 60%) can be rejuvinated, though once a contact groove is cutt too deeply you're in trouble. Still think that the radius on the contact arm should be able to modified slightly & the TPS should work like new. Contact cleaner is a good idea for the first try, but if it doesn't work (or won't move), you can usually get lots more iles out of one by working carefully with it.

There's a thread about this somewhere. If no luck, I have 2 refurbished & one brand new one.

Pat

could it be that it just needed to warm up a bit more? im doubting this idea because it idled for a bit before we took off, and the problem still occured after driving several miles...

The only running issues I've had with my 2L FI car has been points/timing related. Had a miss/hiccup above 2500-3000 RPM. Mostly in higher gears. Started like once a trip. Then couple of times a trip, then continuously.

First time it happened I replaced points, plugs and retimed. Ran fine for 1/2 year. Second time I replaced points with Pertronix and timed. Been fine after that.

Spoke

Doubt it, sounds like you drove it around long enough for a good warm up.

It does seem strange that it was all of the sudden though.

If it was a TPS you should have noticed it progressivly getting worse, still check it, you never know.

Check all your grounds, trigger points, dizzy points

I had a problem like that once.

It was the points in the dizzy. But I have an L-jet... When the thing finally failed on me, it ad turned out that the base of the pointing (?) unit was actually cracked, and at high rpms, the crack would flex open and retard the timing for me.