i have a 95 formula with 112k miles....at about 108k, i had the clutch redid cuz it gave out, and now when im taking off in first, if i dont rev up the engine a bit, the engine feels like its stalling out and then catches itself and take off

the stalling is a shaking feeling more than a stall, it shakes the front end of the car

i cant remember if it did it before i had the clutch worked on as i bought the car just before the clutch died

aside from a flowmaster muff, a de-screened maf, an aftermarket elbow and a replaced fuel filter and iac valve, the car is bone stock.

do i just have to rev the engine harder on take off to avoid the shaking? or is there something wrong with the engine-tranny

Yup, there is/might be something wrong with the clutch/transmission, and I hope that I'm wrong. The guy that changed your clutch could have made a classic mistake if he changed the flywheel. If so, did he forget to transfer the balance weights from the old flywheel to the new flywheel? If that is what happened, then your engine is permanently out of balance and must be fixed unless the weights from the old flywheel are transferred to the new one.

IF this is what has happened, here are your options. (1) The engine can be dismantled and the flywheel, dampner, crankshaft, rods and pistons (the entire reciprocating assembly) must be rebalanced. (2) Another option is that GM might still have a piece of equipment that is bolted onto the engine and then, while the engine is running, tells the mechanic where to put new balance weights on the new flywheel. Or, (3) the mechanic still has the old flywheel and he can transfer the weights to the exact same spot on the new flywheel. If the flywheel is gone, then you only have the choice of #1 and #2.

This seems to be a common mistake. The exact procedures for a clutch change are in the factory shop manual, so the mechanic has no defense.

On the other hand--could it be an ignition misfire? It's pretty easy to yank on a plug wire while under the car and on top undoing bolts and such.

Good luck on this one and let us know how it works out.

Hello,

It's been while since I last posted. As I have done in the past with other posts, I have more questions for you at this point than answers. How does the engine feel at idle, vehicle stationary and the clutch pressed in? When the clutch was redone, what parts were replaced? I'm assuming (we know what a*s-u-me means) that the clutch and pressure plate assembly were replaced. As for the flywheel, was it scuffed up, resurfaced, replaced, or ....... untouched?

I ask about the engine feel at idle because MeToo brought up a point about balance of the flywheel. If it idles OK, shakes only at take off, and then smooths out after you're moving, it's not a balance problem. Even if the flywheel was replaced, as long as it was an OEM piece, it will be balanced for your engine. These things came off an assembly line. But, if your car has been noticeably more shaky at idle after the clutch change, then it may be a balance problem.

If your original flywheel was reused, what was done to it? If it wasn't touched or was just scuffed up by hand or with a grinder, it's most likely warped from the failure of the original clutch. Let's face it, who of us here is gentle with these cars? An abused clutch generates heat, heat warps flywheels. We've all been there. Any way, if it was resurfaced, how rough was the finish on it? Even if a resurfaced flywheel is perfectly straight, if the cut was too rough it wont grab correctly when taking off and will result in a "bucking"/ stalling feeling. But this bucking/stalling will present mostly at take off only. On the plus side if it was too rough a cut, it should eventually smooth out a bit and so will the take offs.

I look forward to hearing back about what was done when the clutch was redone. I hope my rant helps and God bless you.

-Chvrlt283

Quote: "I ask about the engine feel at idle because MeToo brought up a point about balance of the flywheel. If it idles OK, shakes only at take off, and then smooths out after you're moving, it's not a balance problem. Even if the flywheel was replaced, as long as it was an OEM piece, it will be balanced for your engine. These things came off an assembly line. But, if your car has been noticeably more shaky at idle after the clutch change, then it may be a balance problem."

If the flywheel is OEM or even aftermarket--and, if it was changed, and the balance weights from the old flywheel were not installed into the new flywheel, the engine is permanently out of balance. All Firebird/Camaro LT1 OEM flywheels are neutral balanced when made. However, the LT1 engine is externally balanced after it is assembled and this is done by adding weights to the dampner and the flywheel--called "offset" balancing. The flywheel comes pre-drilled for the screw-in weights and these weights must by transferred from the old one to the new one. This info is in the factory service manual.

The engine could idle rather well, with little to no shake, but by about 3,000 rpm, it will vibrate pretty badly. Shaving or machining the OEM flywheel generally will not change the factory balance that much that it can be felt, although rebalancing is probably the best bet.