... and then back to the right when I let off the throttle. Any idea what might cause this?

Thanks!

Something is loose in the rear.

Worn lateral link bushings
Loose lateral link bolts (the long one through the knuckle is commonly loose)
Loose rear wheel bearing
Cradle is severely rusted and the lateral link attachment points are moving.

or.....Broken motor mounts. Sometimes hard to see, but if you jack up the engine a little, the motor mount will show itself.

Thank you - I'll check these out.

I had exactly this situation.....Was going crazy (Short trip!) checking all of the suspension for looseness or damage/wear....Noticed oil dripping from one of my struts- pulled it off and collapsed it...No return; It had leaked and lost all pressure and some fluid. Picked up a new strut and the problem went away.

I push my car hard in the twisties....Handles great but that situation was on the San Mateo bridge- straight shot for 5-6 miles...so very noticable.

Let me reiterate; Pulls to one side under acceleration, pulls the opposite way under deceleration.....The symptoms of one limp strut.

quote Originally posted by fieroguru: Loose lateral link bolts (the long one through the knuckle is commonly loose)

I had been working on the rear suspension of my Formula at a friend's house the night before autocross. When I drove home that night, something didn't feel right when I was merging onto the freeway. There was a slight "wiggle" in the rear end. Seemed minor though. The next day at autocross, the slight "wiggle" turned into a "lose all control" situation... and I came oh-so-close to putting the car through a fence. And yes, I discovered afterwards that the driver side lateral link bolt had not been tightened up properly the night before. Lesson learned!

This fixed it for me....

http://rodneydickman.com/pr....php?products_id=352

Well, it looks like Fieroguru nailed it. I've got all fairly new neoprene bushings in my suspension, so last night I checked all the nuts and bolts on the rear suspension, and they were all super tight with the exception of the nut on the lateral link bolt on the knuckle. I tightened it down very tight before seeing in the manual that this nut is only supposed to be torqued to 36 lbs. (which doesn't seem tight enough). That being said, I loosened it back up until I felt it was at about 40 - 45 lbs. Only got to take th ecar for a short test drive, but the situation seemed to be much better, if not eliminated. I'll test it again after work today, but I think this did the trick. Thanks to Fieroguru and all those who responded. I really appreciate the help!

Does everyone really only torque this nut to 36 lbs., or is it recommended that it be tighter, especially when using neoprene bushings?

Actually the proper torque for the bolt thru the two lateral links at the spindle is; Lat' arms spindle bolt = 37 lb/ft + 90*

Which means to torque it to 37 lb/ft and then twist it thru 90 degrees....so it will be at a substantially higher total value.

ALL of the suspension torque specs are available under the "Faqs & how tos" heading on Pennocks- Link; https://www.fiero.nl/forum/Forum9/HTML/000048.html

Thakn you, cvxjet - I appreciate the clarification! I'll go back and reset the torque, although that's probably roughly where I set it to.