Why Doesnt My Rb25 Have Spark Or Fuel

[Proximity Motorsport]

Hey,

I am putting back together an R33 GTS-T 1995 model and basically the previous owner decided to strip it and I decided to put it back together. Previously it had an RB25DET NEO but I think its just a rb25 S2 loom because the ECU plug only has 2 rows, and there is no ignighter pack plugs

1995 S2 R33 GTS-T Shell

S1 RB25 Motor with NA S2 Coils and CAS

S2 RB25 Loom

S2 AFM

Standard S2 Turbo ECU

The car used to have a patch loom with a Haltech E11v2 and wired into the standard loom was a Apexi SAF-C and AVC-R and today I removed all the splices for the SAF-C and AVC-R.

The car IS NOT sparking or firing the injectors... this is what I have done so far..

The only wire that was completely cut was Pin 27 (AFM Intake air quantity signal) its solid grey in colour. The car did have a map sensor with the Haltech but I have put a S2 AFM back into the car and none of the wires to the plug were cut or tampered with.

Anyway I joined the grey wire back to itself, and when it is plugged into the ECU I found continuity through that signal and the speed and rpm signals although there was alot of resistance. Im not sure if this is okay or not.

Anyway the fuel pump primes when the ignition is turned on, the car cranks, but does not fire. There is fuel getting through the rail. So these are the things I've tried and nothing has worked..

• The ECU is getting power and a good ground and I have tried 2 ECUs
  
• The CAS is getting power, and ground, and signal wire 51 (120 degree) and 52 (1 degree) both have continuity to the ECU
  
• The injectors have power to the main harness although I did forget to check on the plug (I know)
  
• The coils have power and ground to all of them, and the signal wires all have continuity back to the correct pins on the ECU (Pins 1,2,3,11,12,13)
  
• Unbolted a coilpack and put a spare plug in and tried to crank motor with it earther on chassis and motor and no spark
  
• When unplugging and plugging back in the CAS it primes the fuel pump and I tried 2 different CAS's and no difference
  
• I removed the CAS from the cam and turned the shaft the correct direction (with power on and everything plugged in) and there was no spark coming from coils and could not hear the injectors ticking
  
• The main earth on motor is connected to chassis, and all other earths on the loom have been sanded clean, and then paint was removed with a dremel from chassis and they are all tight and connected (as far as I can see!)
  

So is there anything I'm missing here? Is there any way of checking what signal the signal wires are getting on the coils? Is it a positive 0-5v signal? I dont really know alot of auto electrics.

Thanks

[The Dan]

If you are turning the CAS with the IGN on and you are not getting spark or injector pulse, then your CAS is the problem. Is the CAS getting a FULL 12v?

[Proximity Motorsport]

Yes it is, and its out of the motor, although it has been sitting, but was working perfectly okay before. The spare I used is from a R33 that was crashed, and was working perfect before the crash.... hmm maybe I should call around and get a mate to bring a spare around if i can find one.

Is there any way of checking what the signal is getting to the coils? Is it as simple as checking with multi meter?

[GTScotT]

You can take a coil out and pop a spark plug in it grounded to the motor, then take the CAS out of the head and spin the drive with your fingers.

If the CAS has 12v going to it (and the key is to ON) the injectors should click and the plug should spark. If not, try replace CAS.

[snozzle]

yeah had a problem like this too, the internal drive of the CAS was rooted, sometimes worked, sometimes didnt.

new cas, problem solved, try sumone elses cas before you buy another one though

[Proximity Motorsport]

You can take a coil out and pop a spark plug in it grounded to the motor, then take the CAS out of the head and spin the drive with your fingers.

If the CAS has 12v going to it (and the key is to ON) the injectors should click and the plug should spark. If not, try replace CAS.

Yeah thats exactly what I was doing, and I tried two CAS's... but hopefully they both mysteriously died while they sat for the past 12 months running because that was make it an easy fix.

Thanks

[Cowboy1600]

Have you checked all the fuses in your boot?

Start with the green ones.

[DVS JEZ]

you can check the spar drive with a LED test light at the ecu and at the ignitor if yours has one, i reckon to check the ecu wiring at the ecu where the patch loom was wired in,

Oh and was the motor in an auto originally? might need to wire the park neutral switch

[R.3.2.G.T.R]

yeah had a problem like this too, the internal drive of the CAS was rooted, sometimes worked, sometimes didnt.

new cas, problem solved, try sumone elses cas before you buy another one though

exactly what mine was doing, getting normal voltage but internally rooted, swapped with another cas and works normally

[Proximity Motorsport]

hey guys I'm still having drama. Everything looks electrically okay. I have tried THREE Cas's now and they were all working when removed from motors, one working earlier the same day, so definately not a faulty CAS.

To check if the coils are getting signal would putting a timing light over the white wire on coil one work? I'll try this when I get home, at work atm. Have you guys got any other ideas before I start pulling the loom out to change it out for another

you can check the spar drive with a LED test light at the ecu and at the ignitor if yours has one, i reckon to check the ecu wiring at the ecu where the patch loom was wired in,

The Haltech had a plug in patch loom. What do you mean with the LED test light? How would I check it? Just put light to ground and to one of the incoming signal wires of the coils? So the signal is 12v?

[Proximity Motorsport]

anyone got any more ideas?

[The Dan]

anyone got any more ideas?

Take it to a mechanic

[Proximity Motorsport]

Take it to a mechanic

mmmmm................. rather not...

[DVS JEZ]

hey guys I'm still having drama. Everything looks electrically okay. I have tried THREE Cas's now and they were all working when removed from motors, one working earlier the same day, so definately not a faulty CAS.

To check if the coils are getting signal would putting a timing light over the white wire on coil one work? I'll try this when I get home, at work atm. Have you guys got any other ideas before I start pulling the loom out to change it out for another

The Haltech had a plug in patch loom. What do you mean with the LED test light? How would I check it? Just put light to ground and to one of the incoming signal wires of the coils? So the signal is 12v?

an LED test light is used To check small pulse signals such as ignitor signals from ecu to ignitor or ignitor to coils. Also injector pulse signals at injectors. Use them the same as a normal test light.

Can u try a different ecu? Maybe urs is fried

[Don Dada]

Is the 120* and 1* signals from the cas wired the right way around?

[Proximity Motorsport]

an LED test light is used To check small pulse signals such as ignitor signals from ecu to ignitor or ignitor to coils. Also injector pulse signals at injectors. Use them the same as a normal test light.

Can u try a different ecu? Maybe urs is fried

I tried an ECU from a S2 R33 GTS... are they the same as turbo? I also tried my Vipec for rb25 out of my r32 and no difference.

There is no igniter pack because its series 2, but I will try this test light as soon as I get a chance

[Proximity Motorsport]

Is the 120* and 1* signals from the cas wired the right way around?

I would hope not, because the loom hasnt been touched, apart from where I disconnected apexi SAFc and AVCr, only an engine swap as old owner disintergrated the piston...

Ill try testing signal wires through the week next week sometime.

Thanks for the input guys

[rb30dett]

The ecu triggers the injectors & ignition via the earth so check for continuity to the ecu and the earths from ecu again.

[Proximity Motorsport]

Thanks for all the help guys. Checked the cas wires for earth n power, then checked the signal wires, while turning the cas by hand and noticed the signals had permanent earth, so I checked continuity with multimeter and narrowed it down to the plug, so I soldered a new one on and finally, I have spark and fuel. Thanks for the help guys

[DVS JEZ]

good to hear its sorted