[byron911]

Hi

sorry this lengthy question is my first tech post....but help would be most appreciated.



Firstly the car:

1978 SC with an '84 3.2 fitted (wired by a 5 year old I'm thinking)

The said wiring is a nightmare that I'm going to tidy up and re-label as I work through the mess, this I suspect is the basis of the problem.



Secondly, the problem:

The car has started and run well since purchasing it a few months back, however a few times it wouldn't start (It turned over ok) but with persistence and fiddling with the poorly wired aftermarket immobiliser and central locking, it eventually would go. Symptoms included turning the key to 'on' and or start and the door locks would lock after unlocking with the remote key fob.

Anyway, a few weeks back I drove it a few km into town, shut it off and returned a few minutes later and no start. It coughed and ran for a few seconds then died..it's been comatose since.



What I've done to try and fix it:

I firstly removed the immobiliser and central locking including all metres of crappy wiring. It was only connected to the fuel pump circuit

Still no start

I've chased the DME wiring harness and tested the relay, they seem Ok. Power to the fuel pump, earths good, injectors clicking.

I removed the ECU and discovered a blown resistor on the board which is connected to #4 pin on the connector. This is 12v start supply direct from the ignition switch. I removed and replaced the resistor with a newy. I've limited knowledge of electronics, but figured that with a replacement ECU @ $700.00, I may as well try to fix it myself. I cant test the ECU, however I've tested every terminal in the ECU harness connector according to Bentley and all the parameters are OK.

I've removed, cleaned and reconnected grounds

Still no start, however it coughs a little, like it just may run...

I've worked thru the Bentley manual troubleshooting guides thoroughly

Spark....OK. Shorted a good plug to ground and it fires so I suspect a fuel problem

I've squirted carby cleaner into the air intake and it runs for a couple of seconds...it's gotta be fuel right!? I can smell fuel and suspected flooding initially, I've replaced the spark plugs just in case.

But the injectors fire (they were recently serviced) I've tested fuel volume which is spot on, I haven't a coupler the correct size to connect my pressure gauge though so pressure not known. I jumped the pump to 12v to run it without the DME relay and tried to start but still no good.

So, I'm stumped..

maybe there's still a fault in the ECU, maybe a dodgy ignition switch, wiring not earthed or connected to supply properly??

I've ordered a replacement DME relay, although it tests OK

any other ideas please

Greg