Death on sudden opening of throttle

[Barrett Flowers]

diy_efi at efi332.eng.ohio-state.edu wrote:
> 
> I've finally rebuilt my intake system (welded up from steel exhaust
> tubing), but I've got the following problem:

What kind of engine, and how big is the tubing, and how long is it?

> When the throttle is mashed at lowish RPMs i.e. <2000RPM
> the engine dies for about 1/2 - 1 second, before getting its
> act together and then pulling strongly.
 
> My setup has a second set of injectors mounted on the runners,
> if I switch to use these a the primaries the problem gets much
> worse. This indicates to me its something like fuel dropping out
> of suspension.

Are they the same type injector and same spray pattern? Mounted in the
same direction?
> 
> Changing the injection timing (Sequential system) does help a little,
> but not much.
 
> Q. Whats happening here? Theories anyone?

Possibilites:
Ignition timing
Low port velocity due to runners being too large
Valves too large/small
Spark plug gap
design problems 

> Q. Do other people here have this problem? Whats the solution?

advancing the cam 4 degrees may help.
 

     -Barrett                                          
vette at disknet.com
     1989 Carroll/S.C.A.R. Performance Corvette
     Paxton S/C, Borla, FX-3/z51/HD Springs, Exorbitant engine mods.
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     1984 S.C.A.R. Performance Corvette- Mod Engine, leather, TCI 700-R4
     ICQ contact # 6317092   Owner: SCAR PERFORMANCE
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     Southern Indiana, near Louisville, KY
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