The V8 Owners Forum -

As some of you are aware ive been unable to get a spark on my range rover 3.9 v8 1990. Ive previously removed the dashboard to have the loom repaired due to it burning out.
The loom is all back in now but it just doesnt want to spark.

The coil is receiving the 12v ign feed from the white wire. Ive checked the wiring diagram and all is wired as it should be. Ive now replaced the ignition amplifier and the coil but it still will not spark.

The only thing concerning me now is the fact that the ecu is wired from the coil negative.

Any ideas before i put a match to it !!!

wayno wrote:
....The only thing concerning me now is the fact that the ecu is wired from the coil negative.

Any ideas before i put a match to it !!!

Where was it wired from before the big meltdown? Or was all evidence destroyed in the fire? maybe it needs its own +ve power supply? Doesn't the wiring diagram show much?

Can you not disconnect the ecu and just see if you get a spark on the ignition alone, or is it all integrated into one? All these ecu things are well beyond my meager knowledge of electrickery.

Was running perfect before the wiring burnt out. Its wired exactly as it should be a company called simtek refurbed my loom and theve made a spot on job.

Ive tried disconnecting the feed to the ecu i think its only a reference wire for engine speed.

Ive fitted a 3 pin amp and used the adapter loom.

Can anyone tell me what the wiring colours are. Ive been told by the place i bought it from but just want to double check

put a test meter on the +ve on coil
and see what reading you get,
if it goes to 0 there is your problem the coil is getting no power while cranking.
will need to check the ignition switch and i think the coil gets a 12v feed from the starter while cranking, someone will correct me here.

Hi there chaps just thought id let you know after many swear words and slammed bonnets i finally decided to let an auto electrician have a poke at getting my car sparking.

After a couple of hours several multimeters, osilloscopes and cups of tea he finally pinpointed the problem to be an incorrect air gap ???? WTF !

After previously replacing the amp and coil i was stumped to why it wouldnt spark. Even though i had not touched the pick up module and it ran fine before the wiring episode the gap was incorrect.

The sparky readjusted the module and the old lady fired into life.

He explained that even though i hadn't touched the pick up maybe my new amplifier was more sensitive and was not recognising the pulsing from the module.

Just like to say thanks very much for the help and advice youve gave me.