Re: Quad-4 (1228707 ECM) Rough Idle Problem

[remaklus@attglobal.net]

I didn't measure the timing with the EST disconnected, just listened
to engine continue to idle roughly.

Also, the timing on the Quad-4 cannot be adjusted, the computer
controls everything.

Shannen Durphey wrote:

> Hold on....  Tell me again how you checked timing, and what your
> results were?  On the dizzy equipped 4 cyls, GM wants the timing light
> connected to the coil wire so it flashes with every plug firing, and
> the timing is set by the "averaging" method, a service manual way of
> saying "a good guess".  The timing can really fluctuate on some of
> those older engines, and I know that trying to time by #1 alone gives
> bad results.
> Shannen
>
> Will Remaklus wrote:
>
> > I also tried disconnecting the EST output from the ECM such that
> > the ignition module controls the timing: no difference.
> >
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