'90 GTST No start - Need tech support

[gxram]

Please forgive my ignorance to any short forms and acronyms in advance . I am not familiar with JDM cars nor the tuner atmosphere that supports them.

I'm working with the owner here on his '90 JDM Skyline that simply will not start. It's got a RB20 Turbo swapped in (DET?). I am not certain about any ECU swapping to support the turbo (we're waiting on that info from the previous owner). The car ran fine up until last week, when one morning it simply did not start. Cranks over, no start. Towed it to the garage, which is where we're at now.

First check was fuel. I don't have a spec, but the pump kicks on and plenty of fuel is delivered to the rail. Next check was spark - No Spark. 3 wire's to each coil, on which I have power/ground/and "E". There is nothing on "E". I also checked the injectors with a noid light, and they do NOT flash. I have not checked if it's positive or ground that I'm missing.

What's stopping me from further diagnosis is I cannot communicate with the ECU in this vehicle. I have a Snap-On MODIS and NISS-1 connector that physically fits but I'm getting no communication. I only have software for North American vehicles, and this is a JDM unit. I was hoping to scope for crank sensor input (No spark, no fuel pulse... made sense) but again, I'm rather stumped.

I'm hoping someone can help with a good complete-vehicle wiring schematic, or a proper ECU pinout (I've googled it, 1001 results... you guys would know best) that I could at least start checking for proper inputs to the ECU. Also we tried another ignitor, did not work. Ignitor was supposedly pulled from a running motor but of course I can't verify that.

TL;DR
90 Skyline JDM RB 20 swap
Wont start
Got fuel
No ignition
No injector pulse
HELP!

Thx,
-Eric.

[Chewy]

no ignition or injector pulse, along with no responses from the ecu could just mean that the ecu is zorched. Talk to the guys at rightdrive, they might be able to send you an rb20 ecu as they're pretty common. Either that or check the crank angle sensor on the front of the head to make sure it's connector is plugged in well and it's wiring hasn't rubbed through anywhere, and even pull it to make sure the pegs that seat into the exhaust cam aren't sheared off for some reason. ( had that issue with an rb26, not cool)

[gxram]

There is no dedicated sensor directly off the crankshaft then? Just the sensor off the exhaust cam? That things huge... is it variable timing?

I'll have to look up rightdrive. Do you know if the ECU should talk to the scan tool as a 240SX?

[Chewy]

The sensor on the front of the head reads off the cam angle rather than the crank. But it does still handle ignition and fuel timing. I would think you'd be seeing some response, since the programming is basically the same. Also it doesn't have variable cam timing. Hope that helps.

I haven't had the pleasure of using that scan tool, but you could try both non turbo and turbocharged 300zx.

[BrianV8]

cam angle sensor controls injectors, if u take it off turn the key off and spin it u will hear the injectors fire. IMO check all the wires back to the ecu or try a new one see what happens

[cschepp]

Your ignitor that sits at the back of the engine covers has taken a shiit. It would be time to give it a replacement! Let me know what happens

[Chewy]

Ignitor just triggers coilpacks dude, he has no fuel or spark.

[cschepp]

^ no he has fuel. I think it should be just the ignitor. Can't be 100% sure but that's what I'm putting my money on so far.

[Skym]

Can use Blazt Consult -

http://www.blazt.biz/

Or Nistune (modify stock ECU so it can be retuned like a new car stock ECU, but can be done in realtime) which has Consult as part of tuning software.

CAS = injector timing, base ignition timing BTDC (ECU adds ignition timing via ignition map to BTDC figure to get ATDC where it fires sparkplug). Brian has already mentioned the procedure to check CAS. Also you'll probably need to remove battery terminals, press brake pedal to remove any left over charge which resets ECU and should get rid of CAS error code.

[beacher1B0]

How about just checkin for ECU codes? If the CAS was bad the ECU would say so, correct?
OP - Find yourself the R32 Engine manual. It will help alot.

[Chewy]

^ no he has fuel. I think it should be just the ignitor. Can't be 100% sure but that's what I'm putting my money on so far.

Oh, my bad, he'd said he had no injector pulse, which along with base ign. is run off the cas.