high idle after fitting 2.4 inlet and 6.8mm TB

gozer_1_4

Good morning
I've just fitted the 2.4 inlet and the 68mm TB to my opel speedster, but since the first engine run, the idle is very high, around 1500 rpm and it doesn't go down even after warming up the engine.
Do you guys ave have any idea what the cause is?

thank you very much 😃

Karlosfandango

Does your 2.4 tb actually work? Everyone over here that has tried to fit it has run into problems and there looks to be no easy fix. Do tell if you have any more info.

blue_se2

68 mm tb is the SC one IIRC?? 2.4 tb is 65mm dunno..
have you reset the ECU

gozer_1_4

the tb is working, i've just changed the wiring and the fuel pressure regulator to make the engine not running lean.
but as far as i know the 68mm tb is the 2.0 turbo engine's tb
By the way it is all working, no engine lamp, no error codes, just an annoying very high idle.
What could it be the reason?

gozer_1_4

blue se2 said:
68 mm tb is the SC one IIRC?? 2.4 tb is 65mm dunno..
have you reset the ECU

Not yet... but i disconnected the battery for at least two days before restarting the engine, so i thing it is the same notsure.gif

blue_se2

yep that should reset it lol.

gozer_1_4

that idle is driving me mad! i really can't figure out the reason why

blue_se2

any air leaks?

gozer_1_4

blue se2 said:
any air leaks?

i'm looking for...

edbutler

Is the Throttle Body Ported?

Some people had these symptoms after some 'over enthusiastic porting' which basically meant the internal diameter at the TB idle point was wider. Porting should be done away from the throttle plate's direct path.

gozer_1_4

edbutler said:
Is the Throttle Body Ported?

Some people had these symptoms after some 'over enthusiastic porting' which basically meant the internal diameter at the TB idle point was wider. Porting should be done away from the throttle plate's direct path.

no, it is not... it is the original gm 68mm TB
By the way, i'm now checking for any air leak...i hope it is the solution

blue_se2

What happens with the standard TB if it's ok rules out an air leak and points to the TB?

blue_se2

also have you rewired the TB i beleive some of the wiring needs to be reversed IIRC.

gozer_1_4

blue se2 said:
also have you rewired the TB i beleive some of the wiring needs to be reversed IIRC.

i think the wiring is ok
The engin is being inspected right now, tomorrow i'll have some news dunno..

gozer_1_4

everything solved! it was necessary to reset again the ecu...
thanks to everyone

blue_se2

glad you got it sorted oh yeah and welcome to the forum!

exmantaa

Please post your engine specs here, as we are very interested to here the outcome of an actual working bigger (SC) TB on the 2.4 manifold. :-)
headwork? cams? exhaust?? reprogrammed ECU?

Thxs

gozer_1_4

exmantaa said:
Please post your engine specs here, as we are very interested to here the outcome of an actual working bigger (SC) TB on the 2.4 manifold. :-)
headwork? cams? exhaust?? reprogrammed ECU?

Thxs

nothing at all...well i know that it won't be a big deal for me having changed only che inlet (2.4), the TB (68mm), clodes the EGR, drilling out the precat and changed the fuel pressure regulator without working on the head or changing the cams... but i'm going to try the car and see if it was worthed or not.
I thing i won't roll it, just trying on track and street.
I will post some impressions on monday.

gozer_1_4

blue se2 said:
glad you got it sorted oh yeah and welcome to the forum!

thank you very much cheers..

gozer_1_4

Hi
Finally i had a chance to drive my car.
My technician says my car now is 15 hp plus and i can say it runs definetively better, quicker throttle response and i can feel an higher torque, but i cant' say if it is real tha 15cv plus or not.
Since i haven't roll it before the work, i'm not going to roll it after...
But in the end, i'm quite satisfied