Idle woes .....

seight · Post by **seight** » Sat Jun 22, 2013 12:17 pm

Well a picture paints a thousand words! Just watched Phils videos and it seems my valve goes in then out when turning ecu on. But he clearly shows it should be out then in. Plus it seems my iac idle steps are arse about tit with more steps at higher temps. But the cranking steps are the right way round.

How did that happen?

No wonder Scott's numbers confused me.

Should be sorting it tomorrow if I can find somewhere that sells a timing light! Bloody dropped mine.

Mike

DaveEFI · Post by **DaveEFI** » Sat Jun 22, 2013 2:00 pm

Can't remember what ignition you have - but my posh timing light
(inductive pick-up, RPM and advance functions) wouldn't work with EDIS. My old basic one did. Had to get it back from my brother.

seight · Post by **seight** » Tue Jun 25, 2013 6:37 am

Timing light bought, timing checked - bang on at idle

But dam, getting this idle valve setting right is a real pain in the ass. I don't have much time to change the setting before it moves off up the temp scale. I'm sure it would be easier if I had a straight forward bypass screw on the throttle!

BTW ignition system is EDIS. I'm just using a base ignition map that Phil supplied which gives 8 degrees at idle. Should I be starting with a 'better' ignition map?
Engine is :
4.2
EDIS
V8D MC1 cam, stage III heads.
ported hotwire manifold/trumpets with ACT plenum.

All advice welcome

thanks
Mike

SuperV8 · Post by **SuperV8** » Tue Jun 25, 2013 12:07 pm

Well a picture paints a thousand words! Just watched Phils videos and it seems my valve goes in then out when turning ecu on. But he clearly shows it should be out then in. Plus it seems my iac idle steps are arse about tit with more steps at higher temps. But the cranking steps are the right way round.

There is a test to do to check the wiring is correct.
http://www.megamanual.com/ms2/IAC.htm (I know I said don't used both manuals

but this doesn't seem to be covered in the extra manual)
It says if the stepper motor works in reverse you should change the wires over.

Tom.

stevieturbo · Post by **stevieturbo** » Tue Jun 25, 2013 12:34 pm

Have the engine idle and test the valve.

ie increase duty and rpm should rise, and less, it should fall.

Once that is correct, set duty to say 10-20% and then adjust your idle to desired hot idle speed using the throttle blade.

After that use idle control to fine tune, cold idle etc.

8deg is a perfectly reasonable timing number for most engines at idle

seight · Post by **seight** » Wed Jun 26, 2013 6:50 pm

Well, got it warmed up tonight. It's still a bit rough on the way up to temp though. However to get a decent idle I had to set it at 85 steps

for 71 C and above. Decent idle was in the 900's any less than that and everything else was jumping around all over the place too much to see what was going on.

That's quite a lot and surely down to having no adjustable throttle stop which means my throttle is more or less closed with no pedal pressure. If I 't cant sort out the idle on the way up to temp then I'll probably have to make one somehow.

Looks like I've got some work to do ! Think I'll leave the idle for a while and move on to the rest of the 'tuning'. Then come back to it when I've got a bit more experience.

Mike