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GTIR no spark


buriedalive

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Slowly working my way through with a GTIR which apparently had a Link fitted at some stage (was last on the road in 2013) so working backwards from #1 I get no spark directly from the coil. I have found that the wiring to the distributor has been modified. I believe the previous owner has deleted the factory ignition module? Anyone familiar with GTIR's able to confirm that? Maybe there isn't one? The module that is there gets very warm so I took it off its bracket. I might put a heatsink on it.

There is power to the distributor (orange/red wire). Coil also has power with key on. 

I have heard of people deleting the ignition modules on S14's etc but they are COP, will that work on a GTIR? 

Other issue I have is when trying to run Trigger Scope it disconnects but I suspect that it low voltage (battery is in the boot) so its on charge. I might borrow another battery to be sure

EDIT : ECU is a NS15X Plug & Play by the way. I just checked my last log file & the ECU is seeing engine speed at least, even if it looks a little weird (I suspect it reconnected as I was cranking the engine)

PXL_20220418_034843585.jpg

PXL_20220418_034856356.jpg

TrigScope.jpg

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The J131 box is an ignitor - I think the GTiR originally had one a bit different to that but that should work.  In your pic the center pin (green wire) should go to ground, the right pin (yellow) should go to ECU Ign 1 output, the left pin (black?) should go to the coil negative.  

Do you get no spark even using the ignition test function?

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On 4/18/2022 at 9:26 PM, Adamw said:

The J131 box is an ignitor - I think the GTiR originally had one a bit different to that but that should work.  In your pic the center pin (green wire) should go to ground, the right pin (yellow) should go to ECU Ign 1 output, the left pin (black?) should go to the coil negative.  

Do you get no spark even using the ignition test function?

That's correct on the wiring or at least Yellow gets 12.5V with the key on and the green goes to one side of the coil. I've tried another coil, no change. 

Shouldn't I get continuity between that yellow wire & Pin #1 (Ignition 1) at the ECU plug?

When I do the ignition test in PCLink what should happen? Is it like injector testing where I can see/hear it working so should I see a pulse at the coil wiring or should it actually produce a regular spark every 5ms if I have a spark plug in the coil lead?

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2 hours ago, buriedalive said:

Ok strangely I get continuity at Pin #25 which would be Ignition 4. Can I just change the output to Ignition 4 via PCLink?

Hmm thats very odd.  Is the wire the same colour both ends?  

If you are absolutley sure it goes to pin 25 it would be best to depin that wire and move it to pin 1.  You cant reassign ign 4 to do distributor ign, it must be ign 1.

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Traced backwards from #1 on the ECU and found the original ignitor wiring (cut off just below the coil). Checked continuity for all 3 wires and they go where they should do so cut off the ignitor plug & joined it back to the factory location. Still no spark but I feel I'm getting closer. No idea what it was wired to before to end up at Pin #25

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Fitted another ignitor to the factory location, still no ignition test capability or spark. Fitted an OEM ECU which I believed was faulty due to visible water damage and found I had spark. Refitted spark plug & Fuel Pump Relay & car tried to start. Refitted Link & found the same positive result. Ignition test now works. Ignitor doesn't get hot so I believe the original must have been faulty. I also believe I have a connection issue near the ECU plug as moving it causes the fans to kick on & off as the Link drops in/out. But I have spark now so I can perform base timing setup.

I do still have to figure out why the Link reconnects when cranking as I can't perform Trigger Calibration

Thanks for your help Adam

Logg 30-04.jpg

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Id start by setting up ecu logging to record RPM and battery voltage at 200Hz, the crank for a few seconds.  Download the log at that will show us what battery voltage is dropping to, and if ecu is completely shutting down or just disconnecting from USB.  

5X3xUuy.png

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  Yes, it looks like the ecu is switching off briefly at the start of cranking.  The red line indicates where the ecu has shut off and you can see that battery voltage was still heading downwards at that time.  You then see it takes a little while for the ECU to boot back up again and this is where you see the RPM jump from zero straight to 215, where as if the ecu was live the whole time it would show a gradual increase in RPM from zero to ~200 as the crankshaft starts to turn. 

Bat voltage is very low, bouncing around only 8.5V the whole time it is cranking and it would drop even lower than that at the start of cranking.  Typically you shouldnt have less than around 10-10.5V during cranking.  It may just be the battery that is tired, if battery is remote mounted often the culprit is cables that are too small or no ground cable from battery to engine (dont use chassis as the main ground). 

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Battery is in the boot. I actually had two batteries connected to try & rule that out as an issue. I had to clean up all the earths when I purchased the car to get any sort of life out of it at all. I'd rather have the battery in the engine bay anyway so I might look at refitting it to the stock location as I'm sure I'm going to have issues getting it re-complied with a battery in the back anyway. I will check the earth cable from engine to body aswell. Thanks

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Has it got a ground cable all the way from the battery to the engine?  If not I have seen that cause large voltage drops as the chassis gets older. 

One other thing you can try which might stop the ecu from shutting down - pin 4 controls the main relay, it may be the big drop in voltage at the start of cranking that is causing this control circuit to switch off the main relay.  Get something like a paper clip pushed in to touch the terminal on ecu/loom pin 4, Connect this pin to ground then the main relay will be permanently engaged.  See if it still disconnects when cranking like that.

UAD73sN.png

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