VEMS : revs rpm dropping off when engine loaded

[A80Avant]

set the kpa value for fuel cut to zero in case you have a value there. That is also under the settings for the fuel cut/resume.

that cured my stall when going on neutral. However the PID in my opinion will not work well that way.

is your ISV located in the normal area that Wagner manifold uses?

[QuattroFever]

ok, had to go for a blast to cheer me up and managed to dial out my surge which im pretty happy about. :mischeif:

It seems that maybe the heat has something to do with it. After a motorway cruise pulling in a garage here and there ive noticed its not as bad. Not dropping off if i press the clutch in on the move.

Still drops a little if you blip it under load. Its a little shaky and idling a little higher than it was in tescos when it was stable. Speedo reads 1150 and vems shows 950-1050. I can live with that!

ISV is in wagner location, felt very hot to the touch when i checked the oil.

Feels like a productive eve. Have to see how she behaves in the morn/next traffic jam.

Thanks to all for the help!!!

[A80Avant]

It is hot because of the location, not because of anything else. I am not sure if that affects its operation. Probably not.

You are getting there !

[QuattroFever]

been out for a drive and its not too bad. same as last night. Guess it will need some tweaking to get it spot on. Idle doesnt seem to want to come down to my general idle setting though.

is that the effect of one of the PID? or maybe was a temperature thing made it lower and that why it went up slightly after I went for a drive?

[A80Avant]

that was excactly my effect of keeping the D high. also in my car once the engine temp goes higher, idle was going higher as well and D was making it worse.

if now it is ok,then at least you have a start.

you didnt tell me where you are!

[QuattroFever]

london, bit of a trek

[A80Avant]

aaa indeed. i will be in london around june time the earliest...

[QuattroFever]

I can stick it out till mrc rr day if you go, it's perfectly drivable and I can still keep tapping away in the meantime.

if we can be drawn away from eyeballing the cars of course.

[A80Avant]

on the 12th of june I will be in london anyway, so that is sooner than MRC. Send me a pm of your email and ill write you a small guide through.

[Jamo]

It's such a mystery why idle is such a problem on all these cars and we need different settings. I've had to revert back to my original settings on idle with NO ignition timing.

Using ignition timing makes my engine sound awful and no better that just using the IAC with PID 35 3 7 and Asymmetric PID Conf

[QuattroFever]

Im currently using
PID 23 7 0

was using
PID 23 7 170

i though that the high D helped with oscillation but when i took it out it made no difference.

It's strange...you think you've got the settings right and the next time you go for a drive its like its rewritten the rule book!


I've given up. I've resigned myself to the fact that the car isn't OE anymore and can't be expected to idle OE.

although it shouldn't be this way, at least I might keep my sanity.

[Jamo]

Oh no don't give up, tuning idle takes a lot of time, took me months for me to be happy, in the meantime you can disable ISV and run on ignition timing only, A4kquattro has posts on the settings

[QuattroFever]

its great 99.999% of the time but it seems when it gets warm ~50 -60'c it starts to hunt a little. and when it gets up in the 80's and you sit still for any period of time it starts stumbling. when the fan cuts in etc etc.

if I go higher than those settings like 24-25-26 it makes the hunting worse and if I go lower it cant recover from the fan cutting in. So I'm pretty confident that the settings for P are about right.

The I is at 7 any lower and it doesn't quite make its targets and higher seems to make no difference until it starts to cause oscillation.

D seems to do naff all...I thought it helped dampen the oscillation but when I was curious and took it out it still done exactly the same as it did with it.

maybe I should try another ISV and see what changes.

[Jamo]

Depends have you got a map you can post up or screenshots of your ISV settings, also remember an unbalanced ve table and ignition will cause the same hunting

[QuattroFever]

there is one further back in this thread but its not current. I have changed my base settings and adjusted my VE table to gain a higher resolution as was recommended. gone back to the req. fuel that peter supplied me with and leaned everything out alot more.

I will post an updated .vemscfg