*Helping a friend* Kade swap into an s12, injectors no fire?

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shift_
240sx Wannabe
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*Helping a friend* Kade swap into an s12, injectors no fire?

Post by shift_ »

Ok so I've searched around quite a bit and have been unable to find what I need, so I figured I'd come to the gurus of the Ka.

Here's the deal, a friend of mine has swapped a kade into his s12.

He has done all kinds of things that I don't know about, I'm just stepping into this mid stream to try to help him out.

So here's the problem, the car will turn over but not start. It will start for a moment with a spray of starter fluid, or a few groundings of the injectors, meaning the ecu is not happy for some reason and not firing the injectors.

Here's what I know:

Tested all wiring from injectors to ecu, continuity check good

+12v to injector harness is good (they will fire manually)

Tested cas as best I could, meaning I rotated it slowly to observe a square output going between 0.2v and 5v, and also tested this at the ecu to confirm feedback to the ecu

Car is in time(or at least close enough to start for sure, tested with light and compression)

There is a red light on in a small window of the ecu that I observed, meaning the ecu has power.

We tried noid lights in the injector plugs and no lights across the board.

So with everything I could think of off the top of my head, all I can think of is that the ecu is not sending the injector signals.

One other thing I thought may be a problem is the maf, but the car should start with no maf signal at all correct? so even if it's unplugged or the ecu is seeing no feedback from it, shouldn't cause this issue right?

What I really would like to know is what (all) feedback does the ecu need to see in order to give the proverbial green light and be happy with the world and let the car start. Are there other sensors that the ecu is looking for on start up that I can confirm/check?


Thanks guys
fully built block, 8.8cr, sc6152s, jdm oem kouki bits
ICEMAN.KCMO
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Re: *Helping a friend* Kade swap into an s12, injectors no f

Post by ICEMAN.KCMO »

So when you turn the distributor over by hand, then injectors are not clicking? Make sure to turn it over by hand to verify. You cant hear the injectors clicking while you are turning over. If the coil is firing, the ecu is/should be sending the signals to the injectors. Is the fuel pump priming? Is fuel getting to the injectors? If the Injectors are not clicking and you are getting spark, I would say it is a bad ecu. But I doubt that is the problem here.
Steve.
shift_
240sx Wannabe
Posts: 109
Joined: Wed Jun 29, 2005 9:37 pm
Location: terre haute, Indiana
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Re: *Helping a friend* Kade swap into an s12, injectors no f

Post by shift_ »

Thank you for the response.

Yes the fuel pump is priming, and if I ground the injectors a few times each, upon the next engine turn over, the engine will fire for a few few seconds, indicating fuel is at the injector and they are working properly.

And also, yes the coil is firing, we have a separate distributor that I hooked up to the harness but outside the engine so I could rotate it easily, and with key power on, when rotated very slowly, you can actually hear the coil spark in the distributor that's still in the engine with all the plug wires connected.
fully built block, 8.8cr, sc6152s, jdm oem kouki bits
ICEMAN.KCMO
Knows Some Stuff About 240's!
Posts: 435
Joined: Sun Nov 12, 2006 8:33 am
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Re: *Helping a friend* Kade swap into an s12, injectors no f

Post by ICEMAN.KCMO »

But you do not hear the injectors firing? If the coil is firing and the injectors are not, it sounds like an ecu. I'm sure you check your grounds. Can you get s spare ecu and try it?
Steve.
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