'89 Corvette injector firing

[Ward]

Virtualy all EFI system change injector firing format at some point in there
dynamic range. Its virtualy imposable for an electromagnetiv valve,
(Injector) to go from near zero pounds of fuel/he to 200#/hr and maintain a
constant stratagy. 

More to the point it makes virtualy no differance in power output which
stratagy is employed. You 89 F car uses right left batch fire and "all"
batch fire. The r/l batch is used most of the time, "all" batch is used near
WOT. Thwese are called double fire and single fire by GM.

This is why TBI system convert to Multi-Port, (if all the time sensitive
filers are re-done).

There are some small gains in emissions for sequental file at or near idle
operation.

Some TBI system never fire in sync with the engine, they typicaly fire on a
12.5 msec clock; with out regard to engine position.

I think the calibration you are interessed in is reflected on the ECMGUY
page, it should be a type $32 calibration.

I hope this answeres your question

Ward


On Sat, 11 Sep 1999 13:01:34 -0500, Jason Haines wrote:

> Does anyone know if the 1989 Corvette ECM changes from sequential to
batch
> fire at a specific rpm or injector pulse width? I know two injector size
> calculations exist in the code (different conversion function but the
same
> flow rate) along with a gallons an hour specification (presumably for the
> fuel economy computer)? I know GM did this on some early ECMs and I
wasn't
> sure if the 1989 computer did this (the 1989 was the last year for mass
air
> flow on the V8 ECM prior to going back to MAF when they went to the FLASH
> EEPROM PCMs).
> 
> Thanks 
> 
> 
> Jason
> 





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