Rb25 With Rb20 Wiring Harness Troubles.

[apl]

Hey Guys,

I just finished a full build on an r33 rb25 in swapped it into my r32. Im using the complete rb20 wiring harness, rb26 injectors with the injector resistor, and an rb25 ignitor or power transistor. Whenever i crank it to try and start it for the first time, my ecu(rb20ecu chipped for rb25) fries a couple resistors inside of it. Ive heard that the rb25 ignitor will not work with the rb20 wiring harness. I have also had no spark when cranking the engine, but all the ignition coils have power. Can anyone give me some hints or help in the right direction?

Thanks alot!

[blind_elk]

S1 or S2 RB25DET? Are they the coils that came with the engine?

[BHDave]

provided the ignitor is wired the right way it will work.

If you have just plugged it in it won't work, but it will not kill the ecu (as i have tried it and my ecu lived)

[apl]

Its an r33 rb25 with vvt. Splitfire coil packs. What do you mean it wont work if just plugged in? It clips into the rb20 wiring harness fine, no additional wiring is needed.

Could improper wiring of the injector resistor do this?

Edited September 16, 2008 by apl

[BHDave]

Its an r33 rb25 with vvt. Splitfire coil packs. What do you mean it wont work if just plugged in? It clips into the rb20 wiring harness fine, no additional wiring is needed.

Could improper wiring of the injector resistor do this?

yes it does, and thats why i said if you just plug it in it won't work. If you are happy to keep going down that path don't read any further....

ignitors are directional. have a look at a 20 and a 25 one side by side. One has the earth on the input side (so 7 pin input plug, 6 pin output), one on the output side (so 6 pin input, 7 pin output). I also think the earth wire come off the middle pin on the 25 ignitor from memory rather than the end one but i could be wrong. haven't looked for a while.

More trivia! On one of them 123456 correlates to cylinder numbers, on the other it's firing order. Again, can't remember which.

[apl]

yes it does, and thats why i said if you just plug it in it won't work. If you are happy to keep going down that path don't read any further....

ignitors are directional. have a look at a 20 and a 25 one side by side. One has the earth on the input side (so 7 pin input plug, 6 pin output), one on the output side (so 6 pin input, 7 pin output). I also think the earth wire come off the middle pin on the 25 ignitor from memory rather than the end one but i could be wrong. haven't looked for a while.

More trivia! On one of them 123456 correlates to cylinder numbers, on the other it's firing order. Again, can't remember which.

You are correct BHDave! Thats for the knowledge. I guess i can stop frying ecus now .

Also, only my first 2 injectors are working. All have power, but just the first 2 open and close. I connected one of the non-firing injectors to a firing injectors plug, and it still didnt work. Is there a test i can perform on the injectors or a way to free them up if they are stuck?

Thanks guys.