Help with tuning

[yoda69]

Vl400 is correct, I'd actual doubled it as the engine ony fires each cylinder once every 2 revolutions, more used to sequential than batch fire.

Yoda69

[darky82]

Ok I get now cheers.

I adjusted the desired idle rpm today, it made the iac drop after it was set again, now the idle screw is all the way out and still sits on 0 steps.

I had no error codes pop up besides a dizzy one, and a trans error they only flashed on and off for a second?

If I have worked it out correctly I get 84% for duty cycle.

[Holden202T]

if your idle screw is right out and the iac is still on 0 steps then my guess is you either have something stopping the throttle from closing right up (accelerator cable maybE) or you have a vaccum leak somewhere thats causing it to get it more air than just around the butterfly.

[darky82]

My car has been suspect to vacuum leak since I built it, everything has been checked and rechecked. I cannot find a leak, I even eyed my manifold up on the engine before installing to check for gaps.
Had a slight gap where the manifold meets the heads on the top edge but pulls flush when bolted down, never a sign of a leak on old gaskets. It was thought that maybe cam was to blame but specs should not cause the problem. Does not like to idle, wants to idle like a ported rotary, but something is giving me a splutter every few seconds than than rar rar rar rar pop pop rar rar pop pop rar rar rar rar rar. It's had engine builders stuffed! But she will drive with out missing a beat?
Crappy idle I have lived with.

I will pull of my throttle body today and have a look around, I guess it would throw a code if it's wiring ti iac.

[darky82]

Also managed to sort out the iac, the throttle cable was too tight.

Incressed desired idle to 9000rpm, it also changes with coolant temp and when setting desired rpm and when driving.

This has also changed my Wideband reading, i got 13.3 wot, was around low 12's high 11's.

[gibbo]

Thats a pretty high idle

[darky82]

Yeh not wrong but seems I bit happier there. How can this throw out FR.

[Holden202T]

i can't see how that would change WOT readings .....

what map reading do you get at idle and what does the wideband say ?

[darky82]

idle new.xdl

[Holden202T]

well going off the idle map sensor 75 kpa ... is pretty high, the cam must be fairly big to do that it would probably be more happy with more spark advance at idle too .... but its pretty eratic, do you have the same main spark numbers in the idle rpm area as in the idle spark table ?

the wideband is pretty much spot on the target AFR at idle, 14.1 i reckon its not in idle afr table at that point ...

i wouldn't be surprised if it would want a bit richer idle too, but thats just something you need to work out from trial and error i guess.