robert112

Hey guys, I did a search but nothing came up.

When lifting off the throttle at say 3 thousand revs the revs obviously go down but as soon as i lift of the gas the revs 'bounce' a bit?
The best way to describe it (damn this is embaressing)
is

vnnnnnnnnnnnnn (consistant throttle and then lift off) vnnnnnnnnn vnnnnn vnnn vnnn vnnnnnnnnnnnnnnnnnnn

so it bounces say 3 times before it goes back to a consistant deceleration..

the best way to reproduce the problem is down gearing. unless i use VERY precise clutch work it is hard to not get this 'bounce' feeling.

mods: stock with 4.77 gears. problem was there before gears but has become slightly more apparent straight after the gears install.

cheers,

Saki GT

What gears does this happen in?

Lionheart

Afterburning like on the old WRC cars to keep the power and turbo spooling

Something with the gas cable that keeps hanging a bit? Gas cable that needs to be readjusted? Does it feels like the car thinks it is still getting gas the first vnnnn's?

mxt_77

If I understand what you're describing, all of my cars do that if I let off the throttle too abruptly. Basically, it's:
release throttle -> heavy engine braking -> car decelerates enough to "coast" (i.e., not really engine braking.. the "thrust" of the car has spun the flywheel up enough to overcome engine braking) -> more heavy engine braking -> again car decelerates enough to "coast" -> etc, until it reaches steady state.

I think higher compression engines and cars with lighter flywheels will have more pronounced versions of this symptom, but that's just a WAG.

ElGringoLoco

Check the throttle cable to make sure it is tight.

I had this issue ALOT at low speeds in first and second gear.

Car would shutter like it was going to stall around 2-3k RPMs requiring me to remove it from gear and place it back in.

I then lent my car to Prospect S and FyreStrike (members on the forum) to Auto-X the car. They said the throttle cable was very loose and when I got the car back the peppy response at low RPM was there and I no longer have this problem.

SheDrivesIt

What did that sound like again?

Sorry, couldn't resist!

robert112

Okay.

I have explained this very poorly BUT mxt_77 is on the right track, it's more to do with a "thrust" thing rather than the accelerator cable.

it's not like the engine is actually making the revs bounce by feeding it gas

it's more like when i down shift ANY gear and don't pay very close attention to riding the clutch and smoothly letting off it bounces the whole car and makes the revs go 'vnnnnn vnnn vnn vn" again
shedrivesit: r u happy now? lol

it feels like an engine mount or gear box mount is broken and one of them is lose and bouncing around ...

imagine a laerner trying to take off in 1st gaer and letting go of the clutch to early. you get a hop/bounce. it's a little similair to that but on down gearing and it's very excessive i have to try really hard not to cause it.

i suspect it maybe normal for a high compression motor with a light fly wheel and the fact taht i have shorter gears now may have only made the matter worse but i'm worried that again, either a gearbox mount or engine mount has stretched/broken.

Lionheart

I would say... Take it to the dealer... NOT normal imo

RACER

[QUOTE=robert112,Jun 20 2007, 05:17 AM]
When lifting off the throttle at say 3 thousand revs the revs obviously go down but as soon as i lift of the gas the revs 'bounce' a bit?

blackout

I wonder if it could be something simple like a clutch slipping. Id go with that hypothesis