sorting out my proflo, one issue

[Ross Corrigan]

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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