VX L67 with 69mm TB Cold start stalling

[immortality]

I've copied over the VS SC IAC tables IAC steps for cold cranking.

I'll get the new memcal into the car tonight hopefully if the missus decides to come home before the hours total darkness.

[immortality]

Put the chip in this morning, First start it stalled as per usual (I'm assuming it hadn't yet reset the IAC), restarted it, the revs started to die but then it picked up the idle and settled nicely so everything seems fine.

I guess the next few days will tell.

[VX L67 Getrag]

Yeah hopefully it may settle itself in, but if not & seems to have helped can add more but just make sure it's not being stopped by max commanded steps & N.O.T. steps are around 20 @ idle with no load items on!

[immortality]

Well, mixed results. Missus said it still stalled this evening.

I wonder if I need to do a full reset on the PCM.

[delcowizzid]

open the throttle blade with the screw some more if its too closed no amount of iac steps will help on cold start then hope the tps volts is still low enough .if it isnt and you cant twist it lower on the screws you will need to trim the edges of the blade or drill a hole in the butterfly

[immortality]

Yeah, I'll recheck the idle steps, I get the feeling that I had left the aircon on the last time I checked it. I know I ended up closing the butterfly blade more than it was previously.

[Holden202T]

The fact it started low then increased idle makes me thin needs more butterfly or maybe initial iac position needs increasing!

[immortality]

Update:

Put the butterfly blade back to it's original position, started car. Almost died but the idle comes up, the slowly starts to die again. Almost like the stall saver is kicking in? Scratch head

Start poking around the wiring behind the blower, sucking noise..... VAC leak

Took about 10 minutes to find but there what looks to be about a 1/4" hard plastic vacuum line, looks like it comes from the TB somewhere and goes to what looks like the purge solenoid( it had pulled out of the rubber elbow, looks like it was glued but the glue has gone off). Refitted, noise gone. It was also fuming around the back of the engine, with the vac line refitted that seems to have stopped as well.

Guess I'll have to see what happens tomorrow morning with the cold start.

Will re-check the operating temp idle steps and TPS volts later after it's had a good run.

[immortality]

Been playing with it tonight (ambient temp about 14° C).

Engine starts fine (always did), it idles fine (about 1200rpm at a guess) but then the idle starts to drop. Before it was dropping so far it died. Now it's dropping to about 600-700rpm, then it comes back up to about 800rpm. I have increased the cold (P/N) idle about 100rpm to 900rpm.

I'll take a log in the morning of a cold start so I can see what it's actually doing on.

[The1]

id check your fueling as stated before, more air needs more fuel, cold start wont be using o2's so it's probably running lean explaining the stalling and other issues. If youve set the IAC to 30steps at hot idle then the rest should be fine, so playing with that will net going round in circles.