Slight Tap Drops Revs

[Manuel Kasko]

Hey guys

Just noticed siting at idle if I tap the accelerator slightly it drops revs then picks up.

Idles at about 800-900 but with the tap drops to near 500

Could this be related to my current issue with my throttle being jerky as I either come off throttle or coming onto throttle.

I been reading up and few people said TPS voltage and with the jerking throttle while driving can also be related to the diff needing to be shimmed.

Thoughts guys please?

[51NNA]

Possible tune related, seen it plently of times.

[Hadouken]

That's jez blasphemy

Do the revs drop the same if you turn the steering wheel?

If so, I say afm

[The Mafia]

List your mods? Maybe it's the T88 turbo?

[51NNA]

No offence against the tuner at all, over time engines sometimes change and the tune might need some more or less fuel from 0% tps

[GTSBoy]

It is most likely that the TPS is not adjusted properly. The way I used to adjust it (RB20, not 25, but should be same) before knowing about what the closed throttle TPS voltage was supposed to be was to set it so that the slightest movement of the throttle would cause the injectors to do their little double pulse (you can hear it happen). That was close enough to the correct setting that it was always fine. The actual at rest voltage is about 0.4v.

[Manuel Kasko]

I will check the TPS voltage when I get a voltage checking gizmo

Tune was only recent and I spoke to DVS about it and he said could possibly be that.

But I only just noticed it doing it at idle so it was kind of hard for him to diagnose over messages

I'll post the results up in here

[Bsa]

My old 32 was doing it then my tps was stuffing up just before tune replaced it and all good

[Manuel Kasko]

Well fingers crossed its something that simple

Im going to get the diff shimmed anyways afterwards

[DVS JEZ]

Yes it will be in the tune, wen it goes from idle map to fuel and ignition map. Ur nistune was a bit of a pain in the tps department.

Remember it was way out and i had to adjust the tps trigger voltage. I mustnt have got it perfect.

Try adjusting the tps slightly either way otherwise i will have to fix it up for u

[Manuel Kasko]

Lol I try forget about that day Jez

We had a shit of a day with the car

Do you have to fix it if I play around with it manually?

[Manuel Kasko]

Actually I remember you showing me it flashing up on the screen and we messaged the nistune bloke

[DVS JEZ]

Yes thats correct. The rb20 ecu has a tuneable tps trigger voltage. Rb25 doesnt as they use a different tps that works off a set voltage to trigger idle maps on and off.

Yes i got it to turn on and off but it mustn't be perfectly adjusted.

U will need a multimeter or consult cable to adjust it. Or u can try trial and error. But make sure u mark it before u adjust it incase u go backwards

[Manuel Kasko]

Ill grab my brothers multimeter once I pay him the case I owe.

Thanks guys

[Manuel Kasko]

Just a quick one guys how exactly is it adjusted?

I can't see a way to open the TPS up

[Bsa]

You leave it connected loosen the bolts and turn it they are very sensitive

[Manuel Kasko]

Okay sweet cheers BSA