Clutch in idle while moving low

[jmcc]

Hey,
I had a vac leak that I'm pretty sure was causing hunting idle, I'm pretty sure I got it, no more hunting. But If I put the clutch in while moving it'll "idle" at ~600rpm and then when I come to a stop duck back up to the usual ~820rpm.

Is this normal for a 1.8t??

I honestly can't remeber if that's what it was like before.

Thanks!
Jm

[Umai Naa!!]

Could be to do with the MAF.

Does it only do this whilst moving, or just when the clutch is in? If the latter, the clutch could be dragging a little.

[Sirocco20348]

I had a hunting idle before and it was due to a filthy throttle body. The car was compensating because of lack of airflow at idle. Once cleaned it was great.

I've had many boost leaks before and they never affected idle.

Have you ran vagcom over your car lately?

[jmcc]

Hmm potential update, I've noticed some, very slight hesitation when holding the revs around 2.5k RPM. No issues under acceleration but when cruising along seems to have a bit of a hickup. I held the revs at the lights and there was a bit of a burble every so often. I'll investigate more tonight when I can get someone to help with the throttle while I have a listen around.

Could be to do with the MAF.

Does it only do this whilst moving, or just when the clutch is in? If the latter, the clutch could be dragging a little.

Only while moving with clutch in, stopped clutch in it pops back up to normal idle speed.

I had a hunting idle before and it was due to a filthy throttle body. The car was compensating because of lack of airflow at idle. Once cleaned it was great.

I've had many boost leaks before and they never affected idle.

Have you ran vagcom over your car lately?

Hmm, most of the stuff on vortex for hunting idle was around vac leaks, and its definitely stabilised since I found it, before it was hunting all the time when idling moving or stationary, and occasionally cutting out completely.

Yeah I do have a throttle issue in vagcom " group 98 error in basic settings", It won't adapt with my ECU, I have spare ECU I got from a wreck when I went and got some interior stuff and it adapts, but I have the same issue with both ECU's.

I've blasted the MAF with MAF cleaner already no change, anyone got a spare MAF I can test out? haha

The hunt continues.

[jmcc]

So good news and bad news,
Good news I ran some liquimolly petrol decarb though the intake and now the idle is stable.

But my new problem is much worse, it's intermittent too just for fun.
Runs fine on the way to work but twice on the way home I've run into this issue.

If im accelerating and then let off to just cruise the engine will start behaving "strangely".. the revs will hold up higher instead of engine breaking and I'll partially lose throttle response, eventually the car will kind of lurch and then behave normally.

If I accelerate harder while it's in strange mode boost builds normally but the revs don't increase, and if they do more slowly than usual.

Finally tonight, if I accelerate hard and then let off quickly the revs just fall to zero and the car stalls.

So yeah, strange, might be ordering a new MAF if you guys think that'll help?

[Sirocco20348]

Tbh I would be tempted to replace the MAF.

When my maf was dying, the car was just possessed. I could push the accelerator down to the floor with zero reaction from the car at cruising speed. I would test with vagcom and it returned figures that were considered good which put doubt in my mind if tge MAF was actually stuffed or another part was failing.

Eventually my maf had a massive failure, so I unplugged it and the car drove fine. Obviously I didn't push the car. Replaced the MAF and it fixed the problem.

Now I have other problems, but the car was badass for a while.. haha

[jmcc]

Tbh I would be tempted to replace the MAF.

When my maf was dying, the car was just possessed. I could push the accelerator down to the floor with zero reaction from the car at cruising speed. I would test with vagcom and it returned figures that were considered good which put doubt in my mind if tge MAF was actually stuffed or another part was failing.

Eventually my maf had a massive failure, so I unplugged it and the car drove fine. Obviously I didn't push the car. Replaced the MAF and it fixed the problem.

Now I have other problems, but the car was badass for a while.. haha

Anyone know the part number for the MAF??

Looks like my housing has been replaced with some OE bit with no part number.

[Sirocco20348]

Anyone know the part number for the MAF??

Looks like my housing has been replaced with some OE bit with no part number.

This perhaps? If have to check the Bentley's..

OEM: 06A906461L

Audi, VW Mass Air Flow Sensor (A4 TT Golf Jetta Beetle Passat 1.8T, MAF) 06A906461L by Bosch