93 V6 SE, manual, hard bucking

[Tedders]

Hi, everyone.

I have a 93 SE V6, manual transmission sweety. It's bucking hard on first start up, that is, when cold and accelerating hard, the engine feels like it's cutting out, then in, then out. It makes the car buck like a mad donkey.

It lasts just a few times; sometimes I can make it stop by depressing the clutch and revving the engine.

When the engine's warmed up there's no problem.

So far I've:
Changed the cap, rotor, spark plugs, wires, checked for vacuum leaks, replaced the IAC valve with a new one (ouch!), checked the cold start fuel line (no problem).

Any intelligent ideas? Fixes?

Thanks!

Tedders

[Gothmog3VZ]

Video of the symptom could help...

I had an issue where the car did that last fall - turns out I got some crap in the gas tank while filling up, and it partially blocked the fuel line at some point, caused the engine to surge and buck if I went past 30% throttle. Seafoam took care of it for me, but if yours only does it when cold, not sure...

[EEngineer]

change ur gear oil
do a seafoam
clean ur TB

[Tedders]

Changed gear oil about four years ago;
Do a Sea Foam where?

What's a TB?

Tedders

[Gothmog3VZ]

Originally Posted by Tedders

Changed gear oil about four years ago;
Do a Sea Foam where?

What's a TB?

Tedders

You basically have to suck in a bit through the vacum line on the side of your intake manifold (I'll post a pic in a bit to give you a rough idea, unless EEng beats me to it). about 1/3 of a can, but slowly so your engine doesn't hydrolock.

TB = throttle body.

[Tedders]

Aaahhhhh... the Throttle body....

I last week sprayed it out with TB cleaner.

Sea Foammmmm....

Cannot wait.....

Tedders

[EEngineer]

for ur problem, get a new fuel filter.
dump a whole bottle of seafoam in the gas tank when it's 1/4 full or even better 1/8th full.
drive it until it's really really empty.

done!