Died won't start

[JJREED]

Picture the scene; Glorious summer evening, driving home from work in my '93 4.0 Chim. In the middle, Yes the middle of the tricky traffic lighted cross roads near home, the engine dies. Unfortunately The lights were red so I had to undergo the shame of being pushed off the junction!!

Anyway got it home, and tried to find the culprit. Usual checks reveal:

All electrics working.
All fuses fine, swapped around a couple of relays and think all is OK.
Fuel pump runs as usual.
Immobiliser APPEARS to operate as the right in the centre of the dash changes red/green and the fuel pump runs.
12V at the coil as expected,
Stepper motor runs.

But - No spark (Connected in an old plug and get no spark)
so....No fire....

Can't tell if the injectors are firing but if I touch them when cranking I can't feel anything, although, i've not done that before so I'm not sure that's an indicator.

Help me I;mm all out of ideas short of ship the thing off to a specialist!

[s p a c e m a n]

I'd start with the ignition amp/coil wiring. Unplug, clean the connections and refit. Where where you testing for spark from, king lead?

[JJREED]

Thanks I was thinking this. I was testing for a spark using a spare plug, although yes I should look at the king lead as well to rule out the coil

[JJREED]

I also definitely have 12v at both coil terminals.

[ClassicChimaera]

So either coil or lead or onto and into,the dizzy, cap rotor arm and or ign module.

This is where having working spares comes in really handy for the home mechanic.
I had coils and ign modules that I'd somehow collected spare as well as good caps and rotor arms I kept after services,
You can work from the most obvious and just change things one at a time until you hopefully get a spark. ( old school mechanics approach to electrics) it can at least discount various parts from your thinking.

Is your battery cranking fast, if so 100A fuse sounds ok.

[InYaMooey]

ClassicChimaera said:

This is where having working spares comes in really handy for the home mechanic.
I had coils and ign modules that I'd somehow collected spare as well as good caps and rotor arms I kept after services,
You can work from the most obvious and just change things one at a time until you hopefully get a spark. ( old school mechanics approach to electrics) it can at least discount various parts from your thinking.

:cough: :cough:

https://www.pistonheads.com/gassing/topic.asp?t=16...

[Steve_D]

If you have no spark then clear from your mind thoughts about immobiliser, injectors and fuel pump relays as they are all on a separate system.
The ignition system is just dizzy coil and ignition amp so just focus on those.
If you have no spark at the coil king lead and you have cleaned/inspected all the connections then the next likely culprit is the ignition module. These do have history for failure.

Steve