Jerking under Acceleration.

As such with older cars things are bound to go wrong. My 88 Bird has an issue when under full load from the motor, to slightly jerk forward. Our family's van had a bad rear end that we replaced not to long ago with a similar issue however it made a loud humming noise at speed along with it. Mine is not humming however it is making this jerking. I am not sure what to check out and any input on the subject would be great.

By "full load" when exactly do you mean? Is the jerk at a given RPM? given boost pressure? given throttle opening? Is it dependent on engine temperature? Please provide us with specific details.

By full load I mean full throttle. I need to drive it soon its not really noticable at half throttle however under full throttle you can tell. It will do it cold. I use it for every day driving so I have been babying it and not really opening it up much. However when I go to the store later I will give you a better analysis.

I would check the fuel pressure if it is doing it under full throttle only. Fuel starvation could cause this. Use this link, its the Fuel System Diagnostics to check everything.

http://www.turbotbird.com/techinfo/Fuel_...ostics.htm

At higher speeds its more prevalent, however but it would link with the fuel pressure like you said zbird. I am sure the fuel pump and everything is still original so I wouldn't be surprised if it was it. I couldn't make it do it today. So I don't know what was up. I will defiantly give that a check however.

You could be looking at something as simple as some over-gapped plugs so you might want to check them, but the fuel diagnostics is a good idea.

I had a similar problem a few years ago on a different car (Escort) and it turned out to be the TPS (throttle position sensor).

Daniel

Well. I apologize for a really late response. Problems on the homestead.

However I have yet to really diagnose it however under heavy acceleration it does the jerking along with really aggressive maneuvers. I tried to do a donut in a parking lot and it just started to sputter and act up while it jerked hard out of it. While backfiring. I think this is the same problem. I have also noticed my car backfires some upon shifts when it is doing this surging. I turned down my Boost Controller to 15psi as anything above it would just cause it to act up.

I am having more free time in the upcomming days and I can get to seeing what zbird said. I will also look what everyone else suggested. Thank you.

Don't mean to be simplistic, but some simple checks are to check timing and ensure your distributor hold-down bolt is secure - I just went through very similar symptoms with my resurrected BlueBird... all's well now, and for no $ at all!

Sharp turns (donuts) with less than about 1/2 tank is going to result in fuel starvation with sputter and missing. Run the fuel system diagnostics:
http://www.turbotbird.com/techinfo/Fuel_...ostics.htm