ECM Fault?

[Bruce Plecan]

I have seen the same as Ludis
Grumpy


| Are you absolutely sure that there can be any additional asynchronous
pulses
| in between? I thought that enrichment is achieved in a normal way - by
| decreasing the time between pulses.
|
| -----Original Message-----
| From: Ludis Langens [mailto:ludis at cruzers.com]
| Sent: Monday, December 06, 1999 4:03 PM
| To: gmecm at efi332.eng.ohio-state.edu
| Subject: Re: ECM Fault?
|
|
| "Akselrud, Boris" wrote:
| >
| > What I found by
| > looking at the signal with an oscilloscope is that there is an
additional
| > abnormal impulse approximately 0.1 .. 0.3 ms wide in between the normal
| > impulses opening the injector. This abnormal impulse comes and goes,
| > perfectly corresponding to idle rpm fluctuation. Even when I step at the
| > accelerator pedal, up to a 2500 rpm I can see the abnormal pulses and
| again,
| > they are not always there, they come and go with 1..2 sec interval.
|
| These pulses are the result of "acceleration enrichment".  Your ECM is
| sensing the TPS opening, and/or the MAP pressure increasing, and/or it
| is opening the IAC.  All three events will cause extra fuel to be
| injected asyncronously of the normal injection.
|
| The question here is - is the AE the cause of your unsteady idle, or is
| the unsteady idle causing the AE?
|
| --
| Ludis Langens                               ludis (at) cruzers (dot) com
| Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
|