Hi guys,

I'm having some problems with my gt engined coupe s not starting. I have had it in a local garage and they have failed to get it running. See below for there description of where it is at. Is there anyone out there that can repair an ECU? I would rather get the one it used to run on repaired rather than take the risk on another used one.

Has anyone got any idea how I can diagnose this issue? I really don't know what to do next! Would anyone be keen to test my ECU on there car and see if the no spark issue is in the ECU? I can't think of a better way to confirm if it is indeed a faulty ECU. I would happily take the risk and post my ECU to a complete stranger from the internet at this point!😂

Have you opened up any of them to see if there are any visible signs of failed/failing components?

I'd be happy to have a go, especially if there are visual clues.

 

Is the present engine the car's original? Is ECU #1 the car's original?

Are the other two exactly the same part number including suffix letter?

VIN might be useful to know.

 

ECU #1 is the only one I have ran the car on. The car is a coupe s. Originally 1.3 carb, when I bought the car it had been 'fitted' with a 16v on bike carbs. I bought the GT conversion from another converted polo. So unsure on the original engine specifics. 

I have not opened any ECU. I will open it up tonight and upload some more pics.

ECU#2 is identical to ECU#1. ECU #3 looks different but all numbers match 1 and 2

Take some pictures of the coil, distributor, wiring near the fuse box. Have you just plugged the coupe S internal loom into the GT engine bay loom? It’s been well over 10 years since I last played with GT conversions but I seem to remember there being some differences on the Mk2 and Mk2F looms.

I will flood this place with pics tonight. The engine was running perfect for a few years with ecu#1 and distributer and wiring as it is just now. So I don't want to change too much if don't have too

 

ECU #2

ECU #3

This is the inside of the OG. ECU #1

Does the lid of the tin box open easily? Is there stuff on the other side of the board?

Here is inside the tin and the other side. Not sure what to look for but nothing jumping out at me

I have had a quote of £210 to repair the ECU. Should I go with the repair and hope that is the issue? It's looking like I don't have much option at this point....

I doubt it’s the ECU, the fact that you can get a spark with one means it’s more likely to be a bad coil or hall sender in the dizzy, possibly a wiring fault.

I asked the mechanic the same thing. Could it be dizzy / hall sensor? he said it's unlikely because it runs perfect on ECU #2. Albeit only for around 4 seconds while it uses fuel in the system as that ECU doesn't activate the fuel pump. I hope it is the ECU as I dropped it off this afternoon for repair!

ECU sorted?

I have had the ECU repaired. When I got it back they had put the attached note in with the ecu. As I had already replaced the plugs and leads, I needed to then replace the coil before installing the ecu. It then fired right up literally first turn of the key!

Happy days

 

Good news.

 

Was the old coil primary short circuited, so only some windings inducing high voltage in the secondary?

Not sure on the exact issue with the coil but it's all up and running again, just in time for an MOT next week.