Low Idle w/ Saturn tuned port EFI.

[Shannen Durphey]

Jemison Richard wrote:
> 
> I apologize in advance for bugging you folks with this but I've got a
> feeling there's something dumb I've done that is precipitating this problem.
> 
> I originally started having a really low idle (500 rpm or less in gear).  No
> increase in revs w/ air on either.  So I checked my codes and the IAC was
> indicated (now I know this meant the IAC was unable to correct the problem).
> At the time I took it to mean the IAC WAS the problem.  I replaced the IAC.
> In the IAC there were instruction stating the plunger should be no more than
> 1" extended.  I double checked this and it was right at 1 inch (it is
> obviously adjustable.  You screw it in one way or the other - don't remember
> offhand).
> 
What is this?  The IAC is adjustable?  I've never seen that, but maybe
so. 
Doesn't sound like the good old GM unit. 

OK, first question.  This idle spped is actually causing problems,
correct?  Not just annoyingly low?

Next, do you have access to a scantool?  What are IAC counts?


Is there any chance you can forward the instructionsfrom the IAC?

Shannen

> Anyway, I've since discovered the coils were both weak.  I've replaced both.
> The sucker runs like blue blazes (for a Saturn - OK you Chevy guys!) but the
> idle isn't one bit better!  I tried increasing the idle with the idle screw
> (makes perfect sense to an old carb guy!), nothing.  So I backed the screw
> off completely.  Nothing.  Then I disconnected the IAC with the idle screw
> completely backed off (and this is what's got me thinking).  This thing
> idles at about 2500 with no IAC and no idle screw setting!  The IAC is
> actually REDUCING the RPM.  Geez, I can feel you guys out there on the floor
> rolling in uncontrolled laughter.  Go for it!  Just give me the answer!
> 
> I'm thinking if I reduce the plunger extension I'll increase my idle.  Am I
> anywhere close?  And if I'm not, where should I be looking!?  I've changed
> and checked plugs, changed wires and coils.  I've checked the wiring from
> the coils to the PCM and have checked the PCM (according to the excellent
> ;-^) documentation I have on hand) and it checks OK.
> 
> Thank you in advance for your assistance and if you've really enjoyed this
> unbridled level of incompetance I'll try to keep 'em coming! ha!
> 
> Rick
> jemisonr at tce.com