sorting out my proflo, one issue

[Tom Sharpe]

>From my experience, the spark map is relatively advanced. Try retarding the spark
at those bad points -- mine has a couple at -10 and -8 to prevent "hunting".  I
think the internal code also needs filters on the RPM and vacuum.  Try different
sizes and lengths for the tube feeding the map sensor.
I also set spark at 10 deg. and run global spark at -2. Tom S.
Mine also has a hot cam w/ "tight" spread.  Idle is horrible but it purrs like a
kitten (large cat) above 1500 when it jumps up on the cam. Vacuum jumps from 10-12
to 18. I would like to make my own tables w/ less spread between cells below 2K rpm
to make tuning easier.

Ross Corrigan wrote:

> I just got my 1980 280zx running with the edelbrock proflo unit sitting
> atop my '98 full roller .520/.523 cammed small block chevy.
>
> The chip I got with it is meant for the ZZ4 cam I'm running as per the GM
> crate motor but I've increased the potential with mixed rockers and
> superior heads....but conversely my exhaust is somewhat poor with a sharp
> 90 and a shallow low rise inlet air setup.
>
> The 'issue': 'rough' possibly stumbling from 1000rpm on up to 2000 rpm at
> mild to mid throttle (ie. if WOT from a stop it's fine and hauls ass)....if
> not WOT from idle and then throttle fed in the whole car shakes as it
> 'fights' to 2500rpm or so and then runs fine.
>
> I tried each of the following as an alteration to the base chip, resetting
> to the base chip b/t each list of points
>
> -I've raised the global fuel modifier by 2%/4%/6% right on up to 20% with
> no change.
> reset
> -raised the fuel at 12" vaccuum by 6% at 1000rpm/2000rpm/3000rpm, no change
> reset
> -raised spark by 6 degrees at 1000rpm/2000rpm/3000rpm, no change
> reset
> -decreased global fuel modifier by 2%/4%/.......on up to -14% for
> 1000,2000,3000 rpm (it smooths the curves b/t the points I give it and the
> ones unaltered)
>
> (I only got it running 2 days ago and am now driving it to work.  I really
> HOPE to get the o2 sensor installed this Saturday which should help me know
> more......the system won't calculate an a/f but it does have a rich/lean
> light for some help....)
>
> Any ideas on what it can be?  At cruise it'll have b/t 20.5-22 " vaccuum
> depending and in idle out of gear it's at 17-18" vaccuum and once in gear
> stopped it drops to 15.5-16" of vaccuum (idle isn't so steady....I'm
> thinking it's due to one exhaust pipe being more restrictive so I KNOW one
> side runs richer than the other, older plugs said that steadily).
>
> It's sitting at 25 degrees spark at idle as well.
>
> Thanks in advance.
> Ross Corrigan  /  Vancouver, Canada      , yes 4.11 R200's once again available
>
> Ahh, finished with that inferno of work and returning back to the lifelong
> ahem, physics experiments :) ) )
>
> mailto:280zx at home.com      ICQ # 11549358
> http://207.212.212.139/~corrigan/gearheads/pics/wheels/sirbg.jpg    where a
> Z belongs
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