RB25 Not getting spark. What could cause this?

[MATTs14]

Ok guys nobody would respond to my other thread so what are all the possible scenarios as to why i would not be getting spark. Have at it!

[MATTs14]

Seriously nobody can help me out?? This forum has really started taking a turn for the worst. Used to you could get on here and people would be willing to help but not so much anymore.

Trust me people, I know what you're thinking. SEARCH! But i've looked through each and every single thread i could find on this particular topic as well as every topic about somebodys rb swap not starting.

I've tried diagnosing the problem by myself but it's just beyond me this time.

I'm thinking it has to be the ignitor. Any input????

[FinkenS14]

Let it sit for a little while longer man. I usually give it overnight.

Have you recently unplugged your CAS, or made sure its plugged in all the way?

Mine doesnt like to start if I disconnect the CAS without disconnecting the battery and connecting it again before I try satrting the car, who knows why. Also make sure its plugged in all the way, and your grounds are all good.

[MATTs14]

I unplugged it today to check and see if the injectors were working and they were but still no spark. I bypassed the igniter and was able to get power to the main white wire to the coils but not when using the igniter.

Is it possible that the igniter could be bad enough that it wouldnt allow spark at all??

Also what grounds should i check? I replaced my intake manifold to a Freddy and the place near the water neck that used to have 2 spots for grounds only has one so i just put both on there. This ok??

What other grounds should i double check?? Does the ignitor need to be grounded??
Modified by MATTs14 at 9:57 PM 8/26/2009

[Joe]

Seriously nobody can help me out?? This forum has really started taking a turn for the worst. Used to you could get on here and people would be willing to help but not so much anymore.

Trust me people, I know what you're thinking. SEARCH! But i've looked through each and every single thread i could find on this particular topic as well as every topic about somebodys rb swap not starting.

I've tried diagnosing the problem by myself but it's just beyond me this time.

I'm thinking it has to be the ignitor. Any input????

56 minutes.

you waited 56 minutes and expected a reply. dude you need to relax. people arent sitting on this forum 24/7 ready to answer every single thread within seconds of it being posted.

not only that but you have provided a piss poor basis for a technical question thread.

what are the symptoms, how do you know (how have you tested it. dont just say "it doesnt have spark idiot") and what have you tried so far.

[MATTs14]

Yea i understand that but i posted another thread and got nothing. At any rate...i tested it by a few different methods.

First of all i tried the old school method of pulling the coil out and the spark plug and seeing if it had spark at all and there was nothing.

I also bypassed the ignitor by linking the 2 plugs together and selecting one cylinder, i chose number 4, and was able to get the test light i was using to blink intermittently when cranking and holding it to the white wire on that coil. I was under the impression that it needed power at all times when the key was on but its possible that i read that wrong. Also it should be noted that when conducting this same test neither of the other wires to that coil plug had power at any time.

This leads me to believe that it is in fact my ignitor but it doesnt make sense that the ignition relay only has power to the main black/red wire and none of the others.

[Joe]

sounds like your not powering your ECU or igniter. you said the ignition relay isnt hot when the key is on? thats a problem. id start with that. there should be 1 constant 12v, switched power from the ignition, then supply power to the igniter when the key is on (switched power is hot) then a ground.

p.s. removing the igniter and plugging the connectors in together? worst idea ever dude...

[MATTs14]

I didnt actually put the 2 plugs together so everything is ok. Nothing was cut and nothing was spliced.

The ecu is working and has power because the fuel pump is priming and the injectors are clicking. The ignition relay does have power going to it but isnt distrubiting power from it.

In a simpler fashion, heres what i did. I have a simple generic test light and touched it to the black/red wire and there is constant 12v power with the key on and nothing when the key is off. I hook everything up like its supposed to be and touch the white wire with the tester. I figure there wont be any power to it until i crank so i crank and still nothing. I'm seriously stuck on this one.

And Joe, i apologize for my impatience and I don't see the need for any hostility on either end, I was wrong and am simply here to seek answers to my unanswered questions. Thanks for all your help as you are pointing me in the right direction and getting me closer to getting it running.

[918240rb25]

did you ever figure out your issue? i'm having the same problem except i get a constant power to all 6 of my coil's but when i crank i get no spark.. i also get power to injector's and fuel pump..

[Cjmartz2k]

I just swapped a stock RB25 motor into my skyline to sell it. It wouldn't start, but I was getting fuel (pumps on, injectors squirting, plugs wet). I pulled a plug and cranked it with the plug in the coil and no sparky. I was using somebody else's already "swapped" harness (R32 to RB25). Turns out one of the relays wasn't getting the power it needed. I just fed it a swiched 12v source and it fired right up.

[stevespeed]

was about to say the same thing, also check the orange wire to the ecu pin.. 43 I think, make sure you wired that so it goes back to the chassis plug for its ground

[918240rb25]

hey ya i have power to my relay's, on one of them has thick wires red/black- red, white, and the small orange, three of them have power to them and the orange is the ground, on the other relay on one wire has power blk/wt there are 2 other bk/wt and one orange, only the one blk/wt wire has power the other 2 don't, do i need to have power to all three of those wires on that relay 2?

update: i searched and the wt/blk wires do not have power thru them but that relay does not come on and one of the wt/blk wires goes into that big white plug and is cut off on the other side, does that need to go to anything?

Oh and the orange wire just goes from the ecu to both relay's and that's it, do i need to ground that wire out?

Modified by 918240rb25 at 4:47 PM 9/8/2009
Modified by 918240rb25 at 4:52 PM 9/8/2009