Intermittant prob- No Spark at plugs

[Rovernaut]

I am plagued by an intermittant "No Spark " problem.
I have changed the Coil, leads plugs, plugs, recently the Dizzy cap and rotor.
I've cleaned the connections on the ignition amplifier rto the distributer. On my 96 Disco V8 it's next to the radiator, not on the distributer like earlier models.
It now happens in the morning after sitting, and also in the afternoons.
My thoughts are it could be the ignition amplifier, but have been told that the later ones are less prone to problems. Also I've been told, if they play up it's usually when the system is hot? Mine does it when cold start.
I also thought it could be the security system playing up intermittantly, but the engine cranks over but there is no spark at the plugs.
Would the security system allow the engine to crank?
The battery voltage appears ok.
I have checked and cleaned the ingnition amplifier connections and visually checked the wires, they seem ok.
After a few minutes I try again and she fires up.
Any help would be appreciated.

[mickrangie]

Would the security system allow the engine to crank?

some turn injectors off, fuel pump etc some disable starter motor...

I'll ask a mate of mine tomorrow (land rover mech) and post

Mick

[Britswed]

Gday

The factory security system can do this but usually the alarm syder just fails.If it is do not replace the syder but fit a link wire then wont happen again.

What sort of rotor button did you buy genuine or aftermarket???

The cheaper aftermarket rotor buttons arent the best

Cheers Malcolm

[auto_eng]

I'll second the dodgy rotor cap possibility. When I changed my RR ignition to electronic I used a 96 disco dizzy. It came with a brand new rotor button that had a fault and would intermittantly short to the main shaft in the dizzy. Have a look for any burn marks.

Have you tried running your engine in the dark with no lights on? Best way to see if you are getting a short somewhere.

I have a new ignition module for a 96 dico that came with my dizzy. Let me know if you want to try it and I'll send it to you. I changed my to a Bosch unit so don't need it any more.

[madrangie]

Try looking at the resistor power wire going to the coil ( the white one) it most likely will be breaking down from the in line(on fire wall) plug to the coil . I had the same problem a few years back . easy fix replace 1/2 metre of wire and runs great agian ..
Joe

[Rovernaut]

Thanks for all the replies and offers.
I will have a good scratch around on the week end .
I still think it's the module. But then again I might have a break on a wire somewhere. I found a couple of times that when I handled the wiring after searching and cleaning it seemed to start after that.
I also found there were connecters on the wiring from the dizzy to coil. I might replace the connection lugs to the coil also.

[Pete85RR]

If it's a total failure to spark, when it's failing try plugging in a spark plug to the lead that plugs into the dizzy from the coil. crank it, and see if it is sparking. if it's not sparking you know its the coil or module or wires that connect to the coil, and not a fault in the dizzy/rotar button.

[Rovernaut]

If it's a total failure to spark, when it's failing try plugging in a spark plug to the lead that plugs into the dizzy from the coil. crank it, and see if it is sparking. if it's not sparking you know its the coil or module or wires that connect to the coil, and not a fault in the dizzy/rotar button.

Thanks already did that.
Last weekend I removed the OEM coil connectors and soldered new (round hole) connectors on. I have replaced the Bosch oil filled coil with a new Bosch electronic coil.
I undid some insultaion tape on the OEM wiring that leads from the coil to the Distributor and found 2 blue/white wires that had 2 separate joining connectors, which on the coil side on the connector has a wire looped back onto the other connector. It made no electrical sense so I removed the connectors, joined the 2 blue white wire together and then soldered the ends onto a single wire which bolted to the coil.
So far it has not had a problem.