[Diy_efi] idle control 1227747

Darryl M Gilbert dgilbert78
Thu Mar 9 03:20:35 UTC 2006

Hello: Yes checked all that. The WINALDL shows IAC at 80 but RPM at 1100,
to slow the engine down we have to close the air bleed more, but for some
reason the ECM likes the 1100 idle speed. The Target table is down at
approx 650 or so, but the ECM will not invoke the table, if it did it
would drive the pintle in more. I can mechanically adj the stop screw to
drive the idle down, but then the IAC counts are off. From what i
understand you want a low IAC count while maintaining the target idle,
but can't understand why the IAC count will not come down to cause idle
to come down. Base idle timing at 0 deg, anytime idle stop is adjusted,
the TPS is re adjusted to specs

On Wed, 8 Mar 2006 18:52:20 -0800 (PST) Rick McLeod
<dunvegan at sbcglobal.net> writes:
i believe there is a target idle rpm vs. coolant temp table, what values
are in it?

also, p/n switch, is it working,?

have you set up base idle speed, meaning is it being mechanically held up
there? most have a connector to open and then set up base mechanical idle
(be sure to reset iac pintle per procedure), then set up tps according to
procedure (I thought it was .5V)

make sure you don't have a vacuum leak, could cause a high idle similar
to mechanically advanced idle speed stop, the close-loop would smooth the
mixture thinking it was supposed to be running that speed

i would start looking for a path of air somewhere other than the
throt-body and iac, have seen that due to cracked non-ported vacuum
especially the line to fuel pressure regulator, will also sometimes suck
fuel if a minute leak in diaphram

good luck, hope this gives U some ideas

Darryl M Gilbert <dgilbert78 at juno.com> wrote:
Hello: 1227747 355cu in SB Chevy. Trying to figure out how to get idle
down to the idle speeds in the target idle vs coolant table. Currently
ECM wants to keep the engine running approx 1100 RPM, with 80 IAC steps.
Temp is at 171 deg F. TPS reading .51 volts at idle, but Idle speed will
not come down to target idle table speeds?? Is there a switch that tells
the ECM when to invoke the target idle table?? I think IAC steps vs
Coolant is for Fast Idle when cold?/ Any help will be greatly appreciated
Diy_efi mailing list
Diy_efi at diy-efi.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.diy-efi.org/pipermail/diy_efi/attachments/20060308/fefd8e3f/attachment.html 

More information about the Diy_efi mailing list