weird problem, s/c v8 cruise control/hunting idle problems

[budwizer]

brief background,
A mates supercharged v8, was running relatively well, then during a track day, he managed to blow the drivers headgasket, and pressurise the crankcase and force oil onto the extractors and cause a fire. so pulled down the top end, put mls headgaskets on, resealed everything and it was up and running with one side affect.

So i managed to get a log before and after the head gasket blowout/engine bay fire. which ill post up if people think it will help.

basically the first log i got it wouldn't log the speedo correctly, so i put it down to the xdf, as this xdf has been modified to suit 2 bar vs bwfw tunes. so i didn't read into it.

when putting the motor in damaged the speedo sensor and had to replace it. during the log performed of it after the rebuild/speedo sensor replaced it was reading the speedo correctly !!!

since then had issues with rolling idle where it would hunt for idle but only during rolling period, plus the cruise control when it activates.. goes up and down like it can't set on a single speed!
if i remove the speedo sensor it has no issues finding idle while rolling.

any suggestions would be fantastic!

[antus]

on my car with 12p there is a minimum speed to use the idle table but i would tend to roll up to the lights and hit the clutch at about 20kph. it'd idle high untill it got to 5kph and went in to idle mode. technically it was doing the right thing but it didnt feel right. i upped the idle speed to 20kph and now it will idle normally rolling to a stop. maybe you need to do something similar.

[budwizer]

Ill upload the two logs before and after the top end rebuild, the adx seems to work for alot of the tune, however im not entirely sure it works for all of it.. As the xdf has been modified to suit 2 bar bins. So it has a flag set for vacuum leak, both before and after rebuild, and runs to well for there to be a leak. So i tend not to believe that.

Antus your theory could be correct. However i can't access the tune to see whats what. But the fact that cruise control used to work properly with the old vss sender.. And yet the adx couldn't read it properly, but now the vss has been replaced the cruise doesn't work and it hunts during low ks.

If i remove the vss signal.. Engine won't hunt for idle while rolling. And cruise won't work. So i don't know whether to conclude that the old vss didn't work therefor the before rebuild the problem was always there? Just didn't get a good vss.
The max vss signal that the pre-rebuild log took was like 15kph.. Now it works beyond 130kph... Lol

As i said ill post log soon. may help.

[delcowizzid]

you will probably find now that the vss is working all the speed related things are causeing issues more than likely the decell fuel cut and accell fuel probably switching from one to the other rapidly makes them hunt along or it can just be the swings of the o2 sensor in closed loop

[budwizer]

Heres the two logs:
i realise that both logs say that there is an error code of a vacuum leak, but engine performance doesn't represent this, so i put it down to the modified xdf.
you can see at around the 47second mark of the "after rebuild" that the rpm that goes from about 1000 to 1200.

vr_$12_v1.03 TP5.adx

Log before rebuild.xdl

log after rebuild.xdl

thanks very much in advance