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Roy Keen
Minden,NV
76 X Glenbrook
[quote title=C Boyd wrote on Sun, 03 May 2020 21:30]Sir, I thought the 4,6,8 engine was started in 1981 with the trunk less Seville? Anyway as a side
note.. the last 403 I worked on with a flat spot off idle ended up being a bad carb gasket under the top plate. I took it off to inspect and replace
accelerator pump. It was at the GMCMI rally in Tallahassee. Jim Bounds had a used carb he gave me for parts and I salvaged the pump and gasket.
Most people remove that idle pusher and the vacuum valve on the front of the pass head and the solenoid on the front of the drivers head, but being
OCD ( old, cranky, dyslexics ) I put it back on.
6cuda6 wrote on Sun, 03 May 2020 20:30
> I think the best ever was Cadillac's 1986 4-6-8 engine.... one of the few cars i never wanted to work on and didnt care what they wanted to pay
> us...i know a few techs that would have liked to hang the engineers that designed that thing.....lol.
>
> Matt Colie wrote on Sun, 03 May 2020 19:38
> > I can (unfortunately) tell you how it ended up like that..
> >
> > After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix it."
> > That meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You would not
> > believe some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so the extra
> > heat would get the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making alternate between
> > rich and lean to keep the cat hot.
> >
> > Great times they were - NOT
> >
> > Matt - the refugee from dynoland
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