[Gmecm] Port injector wiring

[Steve Ravet]

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Robin Handley
> Sent: Wednesday, April 26, 2006 11:04 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Port injector wiring
> 
> > That's the way the factory has them wired, so no problem.
> 
> True, but the factory has 4 injectors on each line and I was 
> worrying that, if both lines are internally joined, then I 
> would be loading the driver transistor with just 4 injectors 
> in parallel instead of 8. Is this ok?

It's fine.  Adding things in parallel reduces the overall resistance,
increasing the current demand, and putting more load onto the driver.
Having 4 injectors instead of 8 means half the load on the driver.
It'll be fine that way.

> 
> I was also a little surprised to see that the injectors 
> aren't just wired between the signal and ground pins - the 
> diagrams that I have show power into one pin of the injector, 
> and the other pin of the injector connected to the ECM signal 
> pin. Then the dedicated injector ground pin connected to 
> engine/battery ground. Is this right for a 1227727/1227730? 
> Should I keep the dedicated injector ground pins separate 
> from other ground lines?

transistor drivers usually switch the ground connection rather than the
power connection.  As far as grounding goes, if you have the schematic
then duplicate it as much as possible.  I don't think the injector
grounds need to be kept separate.

> 
> > I would think you would have some serious tuning to do to 
> get a v8 cal 
> > to
> run your 4 cyl.
> 
> You could be right! I will have a WBO2 to help me, though, 
> and I have devised a way of modifying tables via ALDL while 

Isn't there a port 4 cyl box/calibration you could start with?

--steve



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