Throttle Issue. Stumble and bucking from off throttle to on.
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Throttle Issue. Stumble and bucking from off throttle to on. 1999 Camaro SS, LS1/t56. Only mods are SLP lid and borla catback.
The motor bucks a little bit when I start giving it gas. If I granny shift, no matter how slow I roll into the throttle it'll buck for a second and then accelerate fine. Same if I let off the gas, staying in the same gear, then get back on it, it will buck a bit.
If I stab the gas it will bog fairly hard for just a second then start pulling normally. From what I can tell it'll do it at any rpm. Though, less noticable in lower gears.
The issue seems to affect the decel fuel cutoff too. Coming off throttle, again no matter how slowly, as soon as I'm off it'll engine brake super hard. Harder than I feel like it should. If I let off the gas, then push the clutch in, sometimes it'll clunk the drivetrain. The only way to consistently avoid this is the hit the clutch a second before letting off the gas(not enough to rev, just so the engine doesn't brake before the clutch is depressed)
If DFCO is active and I press the gas, once again no matter how slowly, it seems like it instantly comes out of DFCO and bucks.
Other than the bucking/stumble the car runs perfectly. Pulls hard, no misfires, etc.
I've tested my TPS, and it seems to be working perfectly. Smooth voltage from 0.5 to 4.4. No thrown codes. Last year it threw an O2 code. I don't quite remember the specifics but cleared it and it never came back. A few months later, I located a rather large vacuum leak on the PCV line and that fixed a high idle issue but didn't do anything for my other issue. Hasn't thrown any other codes.
Anyone have any suggestions on where I should look next?
The motor bucks a little bit when I start giving it gas. If I granny shift, no matter how slow I roll into the throttle it'll buck for a second and then accelerate fine. Same if I let off the gas, staying in the same gear, then get back on it, it will buck a bit.
If I stab the gas it will bog fairly hard for just a second then start pulling normally. From what I can tell it'll do it at any rpm. Though, less noticable in lower gears.
The issue seems to affect the decel fuel cutoff too. Coming off throttle, again no matter how slowly, as soon as I'm off it'll engine brake super hard. Harder than I feel like it should. If I let off the gas, then push the clutch in, sometimes it'll clunk the drivetrain. The only way to consistently avoid this is the hit the clutch a second before letting off the gas(not enough to rev, just so the engine doesn't brake before the clutch is depressed)
If DFCO is active and I press the gas, once again no matter how slowly, it seems like it instantly comes out of DFCO and bucks.
Other than the bucking/stumble the car runs perfectly. Pulls hard, no misfires, etc.
I've tested my TPS, and it seems to be working perfectly. Smooth voltage from 0.5 to 4.4. No thrown codes. Last year it threw an O2 code. I don't quite remember the specifics but cleared it and it never came back. A few months later, I located a rather large vacuum leak on the PCV line and that fixed a high idle issue but didn't do anything for my other issue. Hasn't thrown any other codes.
Anyone have any suggestions on where I should look next?
A few things to try: Check torque of intake bolts, they do loosen up. Check block vacuum at idle (there should be some). Clean maf. Use spray method to check further for vacuum leaks. Disconnect maf, see if there's a difference (ignore the CEL light).
