DDK - Die Deutschen Klassiker

Pin10 is an input so nothing wrong there, alas.

One idea (a stretch). The ecu has a number of earth pins. These may be linked internally within the ECU or may be a “star” earth design where each earth pin has a separate function and they are all linked at one place (as per the wiring diagram, outside the ECU). This prevents earth loops / noise. I...

Is Canems a 1-man-band?
Internet suggests he is good & helpful but hard to get hold of. I know I’d have the case open & oscilloscope probes out to trace back the signal, but that’s not for everyone.

If you can establish serial comms with the ECU the microcontroller “brain” is not 100% fried. It may have lost the two output channels used for the injection pulses but perhaps just the high current semiconductors that amplify the microcontroller output. It should be repairable, in that situation.

OK I’ve tried that now I first did the tests on the DME relay and they seem to be working fine - pin 87 is charged up with 12 volts. Then I went to do your test on the injector plug. Tested the first pin and got 12 volts. tested the second pin and got 12 volts again! Not sure what that means. I tri...

Bit of info on the relay. It has two stages. Stage 1 powers the injectors with 12V plus a couple of other components (idle valve etc). Stage 1 is controlled by a 12v feed from the alarm. Stage 1 output also provides the 12V power to stage 2 solenoid which is activated by an earth side switch by the ...

Wiring diagram is useful. Injectors work by a continuous 12v feed and a ground side switch by the ECU. The connector you mentioned, is for the injectors. Pins 1 & 2 are the solid 12V feed, via a common point marked [2] on the diagram, being fed from pin 87 on the master relay. Pins 5 & 6 on ...

sladey wrote: The gearbox was earthed properly so I would think the starter would have earthed through that

Doh. When you said the earth wasn’t connected I assumed you meant the main earth strap.
Ignore me. [emoji2359]

There is a chance you’ve fried a small earth wire (sensor earth or similar) as the starter motor earth would have taken any possible return path. Haltech recommend earthing the ECU & all related components to the engine block for this reason. So there is no alternative path back to the battery,...

There is a chance you’ve fried a small earth wire (sensor earth or similar) as the starter motor earth would have taken any possible return path. Haltech recommend earthing the ECU & all related components to the engine block for this reason. So there is no alternative path back to the battery, ...

If there is a chance Loctite has been used, heat up the big nut to release it. I’ve broken big sockets in the past when they should have been okay because loctite red made a big torque into a ridiculous torque, so i play it safe & warm the nut/bolt.

Ignore it.

Sounds a bit like road noise from old tyres or a noisy driveline bearing/ component. Low frequency drone that appears when speed is above a certain point & doesn’t really vary in pitch?

I guess Porsche benefits as they are a form of halo model that adds to the brand value. Perhaps there are limits on what they can do themselves with low volume cars & still make a profit. Why make another 959 as a halo model (which was sold at a loss) when you can sub-contract instead? I also wo...

Squirt a little brake cleaner into the air intake & see if that stops the hunting. The car will run on the brake cleaner when the fuel drops out, but if it’s a spark problem this will not act as a temporary fix.

The hunting is probably because the pressure isn’t enough to open the injectors, until the pump builds enough pressure then they open & pressure drops until they shut, then repeat.