Thread: DISCO 3.5 EFI Not starting?

Originally Posted by garciaj

Any ideas why there appears to be no spark/engine wont start?
Replaced the dizzy, base plate in the dizzy, black module on side of dizzy, changed coils and leads but still no spark. Appears that the coils is working but no spark.
Checked the fuel pump, changed the plugs and tried a different computer and tried a different dizzy also.
Even have the guys at the shop stumped.
Engine has had the top end rebuild recently and ran fine for 200 kms and I went to start it and it just wouldn't fire, just winds over freely.
Would appreciate any suggestions as I'm over driving the Nissan patrol!

Been there done that - all of it except repacing the computer.

In the replacing of parts did you replace the distributor rotor with a non-Lucas rotor? I stumped the sparkies too until we put back the Lucas rotor; and all was good. It's documented on here, so have a search.

Good Luck

Grant

`Had same problem with my old 3.5 somedays start and others not. Spent $1000 on a fuel injection specialist who sent computer away with no joy. Tracked it down to all the ( New) spark plugs were stuffed. They were replaced and it ran fine and started all over again. It turned out that the ignition switch was stuffed and separating from the back where it plugs in. Worth a look before you spend big . Good luck

My brother had one, there is a vacuum pot on top of the manifold that cuts out the injectors under high vacuum. If its faulty it cuts them out even more. Easy to find, on drivers side of manifold (I think) just join its two wires together and see if it works then. I took my brothers one out and it never had a problem. Lucky he had a factory manual, he had managed to swap various fuel pump relays around when it first stopped, and they are not all the same! I will also recommend swapping the rotor button, I had one short circuit through to the shaft. Hard to spot but obvious when testing for spark at the coil lead then at a plug.

is the rotor button turning when you crank the engine ?

The rotor is turning but will try a new Lucas one.
I also checked the ignition switch, that was a problem in the past.
Hoping the new rotor will fix the problem.

Changed the coil lead into the cap? Changed the dissy cap? If a sparks getting sent from the coil it can only really be one of two things - the rotor or the cap itself. Is there any spark at all at the plugs, or is it a very weak one (i.e. not enough to fire the engine)?

Originally Posted by garciaj

Any ideas why there appears to be no spark/engine wont start?
Replaced the dizzy, base plate in the dizzy, black module on side of dizzy, changed coils and leads but still no spark. Appears that the coils is working but no spark.

Did you buy one of those cheap chinese Ebay Dizzy components???

Install a Genuine LUCAS rotor
Install a Genuine AMP ... The amps on the Ebay $120 dizzys last about screw all seconds .......
Install a genuine "black can" coil ...

if your using those Bosch style eletronic coil unit's ... Toss it in the bin

Try starting the motor at night (complete darkness) and watch the leads for arking out ... I have split brand new leads inside of a month of purchase

Also ... have you checked that your getting full voltage feed at the coil???


Mike

Well, it's finally come to the end and the disco is going.
After fitting a new dizzy, new coil, new leads, black boxes and modules and new plugs and god only knows how many other parts. Swapping parts from another disco and a lot of head scratching didn't help, it had to be taken to the auto sparkies, who tracked it down to a broken wire.
It may appear that when the engine was pulled out to rebuild the top end and fit the new cam and etc that the damage was done to the wire.
It just seemed strange that it done about 200 kms before the trouble started.
At least one good thing that as come from it, is that it as a new ignition system in it so fingers crossed I might get some troubled free miles?!