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Discussion Starter · #1 ·
I recently put a full exhaust on my 929, change valve shims and when I got done putting everything back I had no spark. After looking over the wires and connections couldn’t find nothing I pulled the harness out. I then re checked every wire and put the harness back in , still no spark but now I have no prime. I have 12v going to the coils and all through the black and white wire connecting all the fi components. My engine stop relay sends power to fuel cut relay but the pump don’t prime and there is no power going to fuel pump. The pump will prime when I use a jumper wire in the relay connecting the black and white wire to the brown wire going to the pump. I checked my timing and that is good. My zener diode was bad or so I thought because I tested it after I removed the harness and got 10 v but after order 4 packs of them I still could not get 9v by using 1 diode but apparently you have to put it in backwards , Anyway I just used a 12v to 9 v Adapter and I’m getting 9.3 volts at the ecu. Please please please help me I’m stumped!!!!!
 

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ok, so you have 12v on the injectors and the coils? the power goes to all injectors and plug coils, then earths through the ECU. I'd be checking continuity back the the ECU plug, and all ground connections from the battery to the engine, swap relays to double check them too, or bypass them and see it that works.
 

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Discussion Starter · #4 ·
ok, so you have 12v on the injectors and the coils? the power goes to all injectors and plug coils, then earths through the ECU. I'd be checking continuity back the the ECU plug, and all ground connections from the battery to the engine, swap relays to double check them too, or bypass them and see it that works.
Sorry for the late reply, and to answer your question I’m not getting voltage to secondary coil wires(colored wires) unless the plug is grounded .I have continuity from them to ecu so I know they are good. Also I bypassed the side stand and bank angle sensor, I am getting 9v to ignition. When I test all relays for continuity they all work while hooked up to battery , however after switching them around , none work on fuel cut. I tested everything man, I bit the bullet and orderd a new harness and ecu. I’m praying this works. I should have them both within a few days. I don’t know what else it could be. Also, I tested the brown and black wire for ground at fuel cut and ecu and neither have it.
 

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If there is 12v on the black/white wire at the relay then that is good! The black/white also powers each coil and each injector so check you have 12v there also and each item earths through the ECU, so the coils, injectors, fuel cut off relay all get power from the b/w and earth through the ECU.

The ECUs are pretty reliable so I'd be looking for corrosion in the multi pin connectors and also in the junction box in the loom here at the RH side in the loom. the pins corrode and cause endless electrical gremlins!

IMG_3594.JPG IMG_3597.JPG
 

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Discussion Starter · #6 ·
If there is 12v on the black/white wire at the relay then that is good! The black/white also powers each coil and each injector so check you have 12v there also and each item earths through the ECU, so the coils, injectors, fuel cut off relay all get power from the b/w and earth through the ECU.

The ECUs are pretty reliable so I'd be looking for corrosion in the multi pin connectors and also in the junction box in the loom here at the RH side in the loom. the pins corrode and cause endless electrical gremlins!

View attachment 109039 View attachment 109040
So I have 12v on coils and injectors, tested kill switch and it’s good however, from what I just read is the brown and black is ground for fuel cut relay and ecu is supposed to send ground to it in order to pump and I’m not getting it. I do have continuity in the wire though. And I checked that already and found the end was melted a little bit so I cut all the green wires and solderd them together and then the same with the black and white. Still nothing. So far I tested kill switch, side stand, bank angle, engine stop relay, headlight relay, 9v from ignition to ecu, I re checked my timing 3-4 times, I even replaced the cam position sensor, I checked the ignition pulse, I checked just about every single wire for continuity and the only problems I found was 1. The orange ground block was melted at the end, I cut and fixed. 2.engine stop sends power to fuel cut and to injectors and coils and everything else but there is no power going to brown wire in fuel pump . 3 in the manual it says to test 4 spots for ground, on the black plug it’s the 2 green and pink they were good on the grey plug the green was good BUT the green n pink had no ground. It says if there is. I ground check for break in wire between green n pink and green. I found no breaks in either, so I connected it to the green wire to supply ground. So now I do have ground on the green and pink but still nothing!!! I have a new ecu coming in tomorrow, a harness on Wednesday and I’m going to replace the battery. If that don’t fix it then I give up!!!!!!
 

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Ok look I got a 2003 954 and I've been working on this damn thing for almost 6 months. It ran when I got it but had issues now won't even start. I'm confused about a few things . I got no prime. Both wires on the coils are showing hot with my test light. And now I got a single black and white wire with gold dots that's been cut and I can't figure out where it's from. It's runs up to the under seat .. any ideals would help. I do have the repair Manuel and have read it day and night back to front front to back..
 
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