Re: '93 90CS Questions for all the experts out there (long)

[Chris Newbold <cnewbold@transarc.com>]

Chris Newbold wrote:
> 
> Andrew Duane USG wrote:

> > Reset the CO mixture. My 100Q did this until I reset it according
> > to Bentley. If you do it with the hoses connected (or is it not
> > connected?) in defiance of proper procedure, you get this symptom.
> 
> I don't think is is an option on 1993- V6s. Sometime early in that year,
> they deleted the CO adjustment on the MAF sensor and replaced it with
> adaptation logic in the ECU.

To follow up on my own post and to actually provide some useful
information, you tell tell whether or not you can adjust the CO by
checking the connector on the MAF.

Disconnect the harness connector from the MAF: if there are four contacts,
you do have adjustable CO; if there are only three, you've got the newer
system and have no CO adjustment.

You can "reset" all of the adaptive values in the ECU, however, by
cutting power to it for a minute or so. Either fight your way to the
ECU in the passenger's foot well and pull all the connectors, or just
disconnect the battery. If you try the latter, make sure you've got the
code for your radio...

I did this once to see if it would have any effect; I can't say I noticed
any difference, though...

-Chris
1993 90CS 5spd 71k miles