Alright guys heres a weird one
 

Alright guys heres a weird one… I’ve got an 84 GSL-SE. on the way to work when I shifted from 1st to 2nd the car started to violently buck back and fourth so I pressed the clutch down and it stopped, when I let it go it started again…2nd to 3rd to 4th to the point of almost stalling. I barely made it into my parking space.

So on my lunch I took it for a spin and tried to recreate what happened and it only happened in 2nd gear but after that everything was smooth. On the way back home from work it didn’t happen at all…

So has anyone ever had this happen to them?
Or do any of you have any ideas whatsoever?

Oh yeah keep in mind I’ve changed every fluid on the car, oil trans, diff…. everything… twice.

Thank you all in advance for your help.:)

Shift at a higher RPM? That sounds like low-rpm bucking. But hey, I like carbs.

my car did that, its related to things getting worn out. do some maintenance on the TB and check your tps, check your vacuum lines. or you can rev the hell out of it... it will eventually somewhat fix itself.

you may want to check and test the afm, bacv, and the tps. next, check the connectors at the injectors to make sure they are not broken and or loose.

Definitely check the TPS.

If you haven't done so recently, I'd start by replacing the fuel filter.

Wow! thank you all for the advice.:)

I thought so too but when it was happening, I was at about 4k.

I checked for vacuum leaks like crazy and I didn't fine any, I did adjust the tps a little to see if it'll fix my issue, and all of the plugs and clips on my fuel injectors are fine. I also drove the hell out of it on the way back home hoping to clear out what ever was causing that problem.

I know it does need to be changed soon... Ive just had no time to do it lately.

Another little clue... after driving it today I noticed the fuel pump was ALOT louder then it is when I first start it in the morning.

Why are you shifting at 4k? Do you shift there all the time? Rotaries like being revved. Lugging you motor is likely the cause of your problems. I usually shift anywhere between 5000-7000, depending on condition. If your shifting at 4000 you're going to be pulling the motor down way beyond its suitable power range. I try to never cruise much below 3000 either.

Normally I will shift at about 6ish. Its just I was at about 4 grand when it started to buck.

Oh ok. Well does the problem get better at higher RPM?

I agree that shifting at or near the redline is healthy (and fun) for these cars. But a 4000 rpm shift shouldn't be a problem with a properly tuned engine. I shift at 4k when trying to keep noise levels down in town and for heavy traffic. I've never had lugging problems.

It did the first time it happened... when it started to buck I gave it quite a bit more gas... but then when I shifted to 3rd it did the same thing and didn't get better. When I pressed the clutch It stopped bucking so I revved it to about 6k and saw no issues...

I might be thinking too much into it, but have you crawled under there and checked the u-joints on the driveshaft

No I have not... I will check them in the morning

Since when? I shift at 3grand, and everything's smooth and easy (and this is done with a 6 puck clutch on an n/a).

jesus christ you guy's always treat your cars like that? lol. i only shift at those speeds when i'm having some fun, usually, 3k to 3.5k tops for my shifts. everything's very smooth, i do throw in one redline just for carbon build up purposes

lol, I can't remember the last time I shifted under 6 grand. But I have very little self control... :)

I had very similar problems too. I had ALOT of crud and junk in my gas tank. And my car was also making the funny pump noises cause it was cathing gas here and there but not enough to run. I changed my tank cause it was so bad, and I got a bigger fuel pump. You may wanna check the tank for crud build up. These tank seem to really like to rust quick. :)