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Wiring nightmare...

Hi - I've not posted alot on this forum, but i've found alot of interesting things out which have been very useful.

Now i've got a technical question, which totally baffled me yesterday while installing an RB20DET lump into my friends S13 chassis 200sx. The engine came from a working car, which was driven immediately before the engine being taken out and put into the 200sx.

We started the conversion last week, aiming for completion on Friday night, or latest Saturday morning. Anyway, a very knowledgable member of the SXOC who had also done this conversion some time ago gave us a full step by step guide to wiring in the engine. It was my job to follow this, which I did carefully to ensure that everything was ship shape.

We got the engine into the car, connected all of the ancilleries and I pulled in the freshly splined loom, which I then connected to all of the relevent under bonnet stuff.

Then came the testing, we ran the ECU diagnostics, code 55.. alls good, time to test crank, she cranked perfectly. Right its time for the real crank, fuel pump fuse back in, crank... nothing. OK...

We then made sure all the plugs were in the right place, everything was as it should be and re-tried it... still nothing.

The logical thing to do first is to check that were getting spark and fuel... on removing the spark plug and checking that its sparking we get a perfect, strong spark. No worries there then. Now this is the issue...

Fuel... or lack of. There was no fuel being injected. Right, test all the injectors, all have the correct resistance. Test the loom for continuity to the ECU on the correct plugs, perfect. Check the injector loom for +12v on the common side... nothing. Hmm, perform the check at the ECU end for voltage... 12v, then check for continuity from the ECU end of the cable to the plug, continuity.

We figured that is why were not getting fuel, but why not?

Can anyone help? please? :)
 

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Check the injector loom for +12v on the common side
What do you mean by the "common" side? Does the Skyline definitely use a "permanent" ignition live, then open the injectors by giving them a switched ground? Or did you try both terminals on the injector plugs anyway? Did you hear the pump prime with the ignition?
 

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It's my car that Doz and several other members of the SXOC were working on for about 14 hours on Saturday, so massive thanks to them for their efforts...

The Skyline opens the injectors using a switched ground AFAIK. We did try both terminals on the plugs anyway, and the pump is priming with the ignition - and the fuel lines are full of petrol.

Petrol's definitely making it to the rail, it's just not being injected!

It's really confusing and we spent about 12 hours trying to figure it out and didn't get anywhere.
 

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Unless a skyline's injectors are different you should have around 5 volts at the injectors with a switched earth. If you have a spark then the ecu is switching so you should have switching at the injectors. Have you tried a noid light on the injector plug? Im not sure on the rb20det but on the rb25det's pin 101 on the ecu is is for injector no 1. Check you have switching there. If you have there is probably a problem with the wiring loom. If not id be looking at the ecu.
 

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Just looked at a wiring diagram and it looks like the injectors are 12 volt earth switched. Check pin 45 on the ecu for an ignition live, this should also go to the injectors. With the injector plug off and the 'tab' facing up the live should be on the left hand side.
 

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Yep, 12V for injectors, 5V for sensors. Good work with the wiring diagram :) Is the ECU the one used with the engine when it was working? Unless it has been knocked, my doubts would be pointing at the freshly-made loom.
 

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Got it running last night and I'm over the moon :D :D

There was a break in one of the wires. Replaced it, it fired straight up :)
 
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