77 xjs - no start

SYMPTOMS - originally ran well then strated coughing and spluttering, then cutout.
Now she doesn't start at all.

WORKS TO RESOLVE TO DATE
all injectors ultrasioonically cleaned,
suge tank cleaned out,
new fuel filter,
new plugs
new bosch dizzy

I this one of those bloody relays? Or something in the Bosch D jetronic?

Fuel is priming correctly into the system and still runs when ticking over, so its not the pump.

I don't have a fuel pressure gauge but I know in the rails it should be around 26 to 30psi.

HELP!!

 

Firstly welcome to the Forums.

I am assuming Victoria in Aus?????.

When time permits, please do an intro in the New Members Area.

You have done heaps, but.

The original EFI system was operated by a 3 wire trigger board inside the distributor, just below the rotor. These were a failure from the go get, and whilst many still remain, the 4 wire board is bullet proof.

Look at the rear of the distributor housing, and count the wires in the flat mini loom that is there. 3 or 4 wires.

If its a 3 wire, remove the cap, and using a magnet on a stick, wave it over ONE end of that board, and listen VERY CAREFULLY, and you should near the reed switches actually clicking. Then do the same at the other end. If you have clicking consistently at both ends, the board is deemed OK.

Next is the magnet in the heel of the rotor, so MORE CAREFULLY, remove that rotor, and attempt to pick up a small steel nail. It is picks up, that is deemed OK as well. That rotor magnet is not strong by any means, and has no need to be.

If yours is a 4 wire trigger board, then the 4th wire must be connected to a GOOD reliable 12v Ign ON source, and the +ve of the coil is NOT a good source.

The OPUS Ignition system is a mongrel as well, and they just die, all on their one. Usual cause is the brass screws retaining the internal power resistor, of the OPUS Amp in the middle of the V, lose their grip, and sometimes simply tightening them, restores spark.
Most of these OPUS Amps have been moved out of the V, so maybe look around if its not staring back at you. They got hot, and fried, oops.

Turn ON the Ignition, engine OFF, and rotate the throttle capstan, and LISTEN for the injectors to "click" as each segment of the throttle switch is passed over. If you got clicking, good, no clicking is a dud switch, and they are NLA, but I have a new one in the many boxes of hoarded stuff in my shed.

 

Further to Grant's point, depending upon funds etc, new ignition sets for the pre HE XJS are available from SNG Barratt if you end up needing one.