Crank position sensor

[Barry R 0]

Hi all,

 

I am new to the forum but have always found some great answers on here thank you and am now at the point where I need a little help. I have a few 205 GTi's non of which are currently on the road but the car in question is basically a shell, a 1988 1.9 Gti with an engine that won't start. It looks to have been a track day car in the past and as such is very stripped out. I know that the problem is that the injectors aren't firing, I have fuel pressure and the tachymetric relay seems ok, and I am in the process of checking the wiring continuity to various components and have found that the crank position sensor wiring has melted (exhaust i think) and is not connected and I cannot even see where it was connected too but my question is,  will this stop the injectors firing as I gather that a lot of 205's dont have a crank sensor.

[Tom Fenton 1,524]

It’s not used on the 8v engine.

[Thijs_Rallye 86 4 Cars]

Do you have a spark when you are cranking the engine? The hall sensor in the dizzy is main the RPM input for the ECU.

[Barry R 0]

Does that mean its not used to fire the injectors, if so what is it used for? I have had the car running with fuel in the inlet manifold so presume that the spark is being  generated ok

[toolie72 67 1 Cars]

Fly lead from distributor connected?

[Thijs_Rallye 86 4 Cars]

15 hours ago, Barry R said:

Does that mean its not used to fire the injectors, if so what is it used for? I have had the car running with fuel in the inlet manifold so presume that the spark is being  generated ok

 

No, it is used for everything the ECU does, spark is the easiest to check. If you have a spark that means your "crank" sensor is working. If I am not mistaken, the tachy relay needs to see a rev signal from the dizzy before it powers the pump.

 

Never assume something is working because you think it does on an old French car ;).

[Barry R 0]

Thank you for the replies so far, I do have a spark but the crank sensor is definitely not connected, I am sure that my issue is with the injectors not firing. I have traced some of the wires  from the injectors, the grey ones all join and return as one to the ecu but the purple wires shoot off in various directions to various components, SAD device, temp sensor, a relay on the bulkhead (working) and more so I am in the process of checking those and will hopefully find where the crank sensor was connected. Does anyone know where I can find a wiring diagram with cable colours on as the haynes does not show them.

[Thijs_Rallye 86 4 Cars]

The sensor in the dizzy is the equivalent of the crank sensor for a jetronic engine. A jetronic managment system doesn't have a crank sensor.

 

Have a look at the diagrams in the haynes manual, maybe that will shed some light where you can search next. If you have a decent spark which you've checked the crank sensor is working fine and the problem lies elsewhere.