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

neilaura at accessworldnet.com neilaura at accessworldnet.com
Sun Jun 13 03:49:29 GMT 1999


At 09:35 PM 6/12/99 EDT, you wrote:
>Hey all.
>
>I need help.  The computer carb on my 83 Olds 98 (307) has decided to send
so 
>much fuel into the mixture that it pumps gas fumes out the tailpipe.  Is 
>there a way to disable it safely???  Any help is appreciated
>
>Al
>
As far as I remember the Olds was fitted with a feedback Qjet carb. If you
are spitting raw fuel out of the tailpipe it has very little to do with the
computer controlled solenoid in the carb. This solenoid has a 50% duty cyle
in open loop, to give close to a 14.7 - 1 mixture. And then fine tunes the
mixture in closed loop, using the O2 sensor as a guide. 
First things first. Is the float level right (it can be checked with the
carb in place). Are the vacuum hoses on correctly (yesterday repaired a
shady tree mechanics botch job. The carb vent hose was connected directly
to the manifold!.). And lastly Qjets are notorious for leaking at the
blanking plugs underneath (carb has to come off for this one).

Neil



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