Silly stupid injector question...

Alex94TAGT
12-28-2006, 10:19 PM
My manuals are not located in the same city, so I'm in need of online help:

-I was under the impression that, when the key is turned to the ON position, the fuel pump primes AND the injectors fire several seconds-worth of fuel for initial startup. Is this correct?
-Or, do the injectors only fire while cranking, in conjunction with the optispark signals?
-(Or perhaps both above statements are true?)

It's a 1994 OBD1 LT1 TA. I'll post more info if deemed necessary, but this is a pretty generic question.

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(Datamaster shows 0% DC while cranking, which I assumed to be normal. Physical inspection while turning key 'ON' produces no fuel out of the injectors, which I assume is not normal, so I'm a little SOL for the time being.)

shoebox
12-28-2006, 10:30 PM
I don't think the injectors pulse until after there are signals from the opti. Datamaster injector duty cycle values are calculated, so it may not have enough info to do so just at cranking.

Injuneer
12-28-2006, 11:53 PM
There are no "cold start" injector pulses when you turn the key to on. The enrichment is handled by the PCM setting a richer mixture when it calculates the pulse width for cold start.

Alex94TAGT
12-29-2006, 01:38 AM
That's exactly what I needed to know. Thanks to you both~

[Edit] And Whoops -- Didn't know we had a specific Fuel/Ignition forum now. I haven't been online much. Sorry Fred! (assuming you moved it for me).