Got the car back wiuth brand new VHPD engine. Drove for about an hour - lovely.
Then the engine dies - running one moment, next moment the tacho drops to zero and the engine stops pulling. When I try to start
ignition on, everything lights up but no fuel pump
starter key, I hear a relay close at the back of the car, but no cranking
I’ve checked the fuel pump fuse and inertia switch, there is power as far as the MFRU (white-purple). The relay has power to the coil (thin white-purple), but I have been unable to etablish whether the MFRU works correctly.
The ECU is brand new, the Lucas 5A module is matched, it all worked just fine. The Lucas immobiliser seems to work correctly, the Cobra immobiliser has not been changed and seems to disengage.
something basic, like is the battery FULLY charged? Could have enough to light the dash but not enough to crank…
Otherwise Immobilizer gone. There are ways to bypass this but I don’t know how (some people here will come with the answer)
I’d definately check that the alternator is charging the battery - something as simple as a loose wire on the alternator can prevent it from charging the battery, whilst no red light appears on the dash. I know, it happened to me last weekend!!!
I have had the alternator problem in the past - ECU switching off halfway through a race (that I would have won - aaarrrggghh) … but it isn’t that. All the links are good and there was no warning light, plus the battery had enough life to run the headlights for 15 minutes after I stopped while I looked for the problem (it has a bike battery).
It shouldn’t be the immobiliser - both fuel pump and starter loops have been shorted out for years. Similarly it’s not the racing master switch - that would cut out more than pump etc.
It’s something simple and blindingly obvious. I’m about the trace back the wiring to the ECU … I think it’s not getting power and I think it was either a fuse going or a wire break that’s cutting power to the ECU for the tacho to have dropped to zero the way it did.
The loom with the battery and alternator cables had been misrouted and had chafed against the drive shaft - one alternator lead had shorted out and the 40A ECU maxi fuse had blown.