cranks but will not fire

[Thommo]

Hi there knowledgeable LR folks.
D1v8ES Manual on straight petrol. (standard electrics except fitted with dual batts thru isolater etc)
Intermittent (once every month or so) vehicle stalls and will not fire.
Cranks just fine.
Fuel Pump works and fuel being delivered OK
Power to Coil & Plugs OK

Replaced ignition module (no problems for about 3 months but prob now back)
Coil (Standard) appears to be producing spark OK

Usually fires when it is good and ready: (sometimes a coupe of hours)
Some times when it stalls and wont fire I have cranked in gear to clear intersection etc and whilst cranking it fires up but not always.

Can happen with vehicle at running temp or cold.

Whilst checking for spark/power at coil etc and grounding a test light and someone cranks motor it sometimes fires but not always.

Sometimes the fuel cut of sensor activates but I think that is just when I am hammering it off road with big bumps as to does the impact sensor setting of hazards etc. I do not think these are related to my problem.

Every-time it fails and I arrange a tow to get it to a diagnostic check it fires up (once just as I was about to be winched onto tow truck).

I am thinking a loose earth? or faulty security system (factory).
Have had the "spider" harness done a couple of years ago.

Everyone wants to help fault find when fault occurs but vehicle will never do it when I have diagnostics available.

Any ideas friends :(

[nicho]

have you tried removing the fuse for the factory alarm?? my hazards flash when i hit some serious bumps but i shut it down and it restarts fine! Does it only do it when the engine is hot?? Your coil could have an intermittent fault so have you used a known good one for a test mule? just because you can see a spark doesnt mean its a strong one! You say its getting fuel but is it too much fuel? when it finally starts is there black smoke from the exhaust or is it clean? I've seen a lot of posts here about sticky or blocked injectors look throught the archives you may see something similar to your problem

[DiscoClax]

As it's causing you obvious grief I would suggest looking at doing the Bee Utey Bosch module upgrade and going from there. The ignition sytems in our buses are a known weak link and at best marginal. Do the upgrade, check all connections, etc and replace the coil with a MEC717 to go with the BIM024 module. If yours still has the module on the dizzy (like mine had) then that's a recipe for grief. Get it away from there at the very least and remote-mount it near the coil. If the module isn't firing cleanly then the EFI won't be either as thats where it gets it's engine speed signal from. Poor spark + poor fueling = unhappy driver... My two bob's.

[scruffy]

As it's causing you obvious grief I would suggest looking at doing the Bee Utey Bosch module upgrade and going from there. The ignition sytems in our buses are a known weak link and at best marginal. Do the upgrade, check all connections, etc and replace the coil with a MEC717 to go with the BIM024 module. If yours still has the module on the dizzy (like mine had) then that's a recipe for grief. Get it away from there at the very least and remote-mount it near the coil. If the module isn't firing cleanly then the EFI won't be either as thats where it gets it's engine speed signal from. Poor spark + poor fueling = unhappy driver... My two bob's.


My one Bobs worth........Fully agree x 2 Bob

[Thommo]

Thanks for confirming the direction I was heading.
It does it hot or cold.
All fuses checked out OK
Have tried other OK coils but no joy.
(Once changed coils and no joy, put old coil back and after a few more cranks it fired! Go figure!!)
My set up is a coil & ignition mounted together on LH inner guard
Looks like I will replace coil & ignition module even if it is only to further eliminate whatever gremlins are living in my vehicle.
I would really like to sort this issue out as I am starting to think of putting a 4.6 in the future.

Cheers
Thommo

[TooQik]

Sounds very similar to a problem I had which was rectified by swapping the distributor.

Here's my thread if you haven't read it already:

http://www.aulro.com/afvb/discovery-1/120467-96-disco-v8i-possible-ignition-issue.html