Subject: Not diy_efi....how to disable a computer carb

[Don.F.Broadus at ucm.com]

That is a good fix also. My experience with the M/C solenoids is that the
solenoid fails either open or shorted  coil so the part will need to be
replaced anyway and that could be the only thing wrong and the C3 system
might come back on line.

> -----Original Message-----
> From:	neilaura at accessworldnet.com [SMTP:neilaura at accessworldnet.com]
> Sent:	Tuesday, June 15, 1999 8:16 AM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	RE: Subject: Not diy_efi....how to disable a computer carb
> 
> At 03:26 PM 6/14/99 -0500, you wrote:
> >I would still check the M/C solenoid. The solenoid controls the primary
> >metering rods buy moving them up and down at a duty cycle
> >controlled by the ECM and its inputs. My 82 T/A did the same thing your
> olds
> >is doing , running extremely rich. The Q-Jet runs rich because a spring
> on
> >the metering rods pulls them completely out of the primary jets. The M/C
> >solenoid when energized pushes the rods down into the jets leaning out
> the
> >mixture. The only way to bypass the M/C solenoid is to convert back to
> the
> >vac type metering rods if this is possible . Fix the carb or go to a non
> >electronic Q-Jet and non computer HEI, of course the ECM now has nothing
> to
> >do.
> >Don
> 
> That's only part of it Don.
> When the solenoid pulls the needles down and closes off the jets it, also
> opens an air bleed valve to further lean out the mixture.
> Possible options are. Physically hold the needles half way in/out of the
> jets.  Or use a 555 as a base for a generating a 50% square wave, and
> disconnect the engine check light.
> 
> Neil