Saint - That sums it up pretty well even I understand it! Just playing Devil's Advocate here, what if the crank sensor is actually O.K. - what else on a P38 would stop the coils from firing?

I can only talk about the good old RRC which has a completely different set up but the principles are the same but on a P38 the ECU controls the ignition as well as the (sequential?) injection. So if I understand you correctly, the ECU has power, the coil packs have power but no trigger. Is the crank sensor the only trigger for injection and ignition? If it is then crank sensor has to be main suspect but what about immobiliser? could that be a factor?
 
Saint.V8 said:
ECU needs a Crank signal to time the ignition and the cam signal to time the Injections
Click to expand...

If the crank sensor was good but the cam sensor was bad would the lack of injection trigger prevent the ignition signal being sent from the ECU to fire the coil packs?
 
neo2 said:
Ive got two new intermotor coil packs delivered today ive loosend the bracket but they are so tight i cant seem to get them out anyway so left them for tonight and the crank sensor is a new genuine one and ive not tried that ethier as yet as i only got it today but im working 8am to 8pm tomorrow as well...

Whats your thoughts on the gearbox error im worried about that as well...
Click to expand...
Yes the coil packs are a bugger to get at - best wait till you are fully rested and relaxed for that job!! patience is the key with those...

As for the Gearbox issue - that could be caused by low batter yvolts as it is usually the first to show a fault on low volts (that and the Traction Control!).

I am certainly not a Gearbox guru, Bemble and JamesMartin are your guys for that, I'm just a Design Engineer and Autoboxes baffle me!

But the gearbox fault shouldn't stop the engine from firing up.
 
classic kev said:
If the crank sensor was good but the cam sensor was bad would the lack of injection trigger prevent the ignition signal being sent from the ECU to fire the coil packs?
Click to expand...
Looking at the logic of how it works....a loss of cam signal shouldn't affect the ignition - you should still get a spark - and a cough if you squirt Easy Start up the intake...

The Immobilser has been satisfied as it has allowed the BeCM to pull in the ignition relay (15) and send power to the coils via the WHITE wire....


If the Crank Sensor was good and the ECU was good, you had power to the coils and an earth from the coils via the Sparkplug bodies to the Engne case- all the wiring is good and sound......there should be no reason not to get a spark.
 
Saint.V8 said:
Looking at the logic of how it works....a loss of cam signal shouldn't affect the ignition - you should still get a spark - and a cough if you squirt Easy Start up the intake...

The Immobilser has been satisfied as it has allowed the BeCM to pull in the ignition relay (15) and send power to the coils via the WHITE wire....


If the Crank Sensor was good and the ECU was good, you had power to the coils and an earth from the coils via the Sparkplug bodies to the Engne case- all the wiring is good and sound......there should be no reason not to get a spark.
Click to expand...

I'm kind of talking as my behind guides me here but would an earth fault explain the loss of ignition (and injection?) trigger? Anyway, I'll leave you guys to it 'coz I don't think I'm really helping out here. Good luck.
 
So in a nutshell i need to fit the crank sensor and the coil packs next and take it from there yeah.....

On the other hand id gladly take ricks offer of fixing m car in 20 mins lol


Saint = yeah its showing traction control error as well but like i said it never showed a fault and drove perfect untill i parked it up and then it started all this **** so its not mechanicle gearbox error got to be electronic side...

Rob
 
classic kev said:
I'm kind of talking as my behind guides me here but would an earth fault explain the loss of ignition (and injection?) trigger? Anyway, I'll leave you guys to it 'coz I don't think I'm really helping out here. Good luck.
Click to expand...
Lack of Earth to the engine itself could result in no spark or one that is so weak it is indistinguishable as there would be no way to earth the coil...

there should be some king of earth path as the engine is bolted to the gearbox which is connected to the shafts to the axles which are atached to the chassis....

But you do need a decent earth strap on the engine to get a real good spark...

And you are helping - you are pointing things out, and question my logic - which is great as it helps us all to reallly focus in and ensure we have checked everything.
 
neo2 said:
Kev i got lost off 200 posts ago lol
Click to expand...

Thinking on what Kev said,when you tested the coils did you report that 2 of the pins showed no earth.I know you said one pin on each showed 12v and one must be the trigger wire,but surely one of them on each coil should be an earth??? Am i gibbering :confused::p
 
neo2 said:
So in a nutshell i need to fit the crank sensor and the coil packs next and take it from there yeah.....

On the other hand id gladly take ricks offer of fixing m car in 20 mins lol


Saint = yeah its showing traction control error as well but like i said it never showed a fault and drove perfect untill i parked it up and then it started all this **** so its not mechanicle gearbox error got to be electronic side...

Rob
Click to expand...
I am pretty certain the GB and TC faults are battery related.

Yep fit the coils and Crank sensor as far as I can see, beyond tracing the wiring through and checking for continuity from the ECU to the coils, they are the only things left.....

If on fitment we still get no joy - I'm stuck and have exhausted my knowledge on the Petrol P38....

I am sure Rick can do a much better job than I as he deals with them day in and day out - I design Jet Engines (well parts for them!!).

If Rick won't come up to you, do you have a way of getting it down south?
 
rodntod said:
Thinking on what Kev said,when you tested the coils did you report that 2 of the pins showed no earth.I know you said one pin on each showed 12v and one must be the trigger wire,but surely one of them on each coil should be an earth??? Am i gibbering :confused::p
Click to expand...
As can be seen on the attached schematic - the coil pack doesn't have an earth....

The Power is fed to it through the WHITE wire, and the ECU fires of each coil in turn by earthing through itself (the ECU is the earth)
 

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Will do i will keep you all posted as well...

I cant get it down there i dont think fingers crossed he fancies a drive out lol...
 
Saint.V8 said:
As can be seen on the attached schematic - the coil pack doesn't have an earth....

The Power is fed to it through the WHITE wire, and the ECU fires of each coil in turn by earthing through itself (the ECU is the earth)
Click to expand...

:praise:

You are good at this SaintV8:D:D:D:D:D
 
Just to throw my 2p in the ring, have you checked relays for switching?
Petrol engines need fuel air n spark: you have air only!
A lot of cars use an earth via/from ecu to switch relays, so try a volt drop from engine to battery.
Or run a supplementary earth from engine lifting bracket to batt neg. (A jump lead works well!)

Do you have a noid light?(approx 15.00 for a set from unipart. Basic led which fits into injector plug!) Check injector pulse with it. If you have no spark, no fuel pump run and no pulse, something ain't switching!!!!!!!!
Some immobilized systems and inertia switches will allow crank, but no fuel pump or spark!
Later inertia systems are triggered by air bag ecu!
Have been caught out by Vauxhall vectra cranking but not firing due to immobiliser chip missing after key being dropped.
Also changed wheel on vw golf after it was kerbed and had to clear airbag light as it was cranking but not firing also.
AND (sorry to go on!) had Ford Scorpio non starting after head gasket being changed, cranking not firing, traced to an earth strap, one of 6 or 7, not being connected back on to battery earth.
ALL of these took time to diagnose and locate, and minutes to fix!!!!!!!
SO HANG ON IN THERE BUDDY! YOU CAN DO THIS!
As Morpheus says in the movie" You have to believe, Neo!"
 
I think Saint has this one licked. The original short basicly sent 12v up everything with a connected earth. The better the earth the more likely it would be to get damaged. The coil packs have no earth but the crank sensor is bolted directly to the block and you cant ask for a better earth than that. Change the crank senor (20 mins job) and i am willing to bet Ant's salary that it starts :)
 
Sorry chaps if coil packs are that hard to fit ,isn't it better to fit crank sensor first it might just be that,Then coils at least you would know what it was rather than both together ...,with the crank sensor don't they have a shim to stop
It being damaged by the flywheel tang be Carefull
 
Last edited:
defender300td1 said:
Sorry chaps if coil packs are that hard to fit ,isn't it better to fit crank sensor first it might just be that,Then coils at least you would know what it was rather than both together ...,
Click to expand...

Agree with that. easier job, and it'll be proper frustrating not to know which it was when she fires up!!
 
jt_armstrong said:
I think Saint has this one licked. The original short basicly sent 12v up everything with a connected earth. The better the earth the more likely it would be to get damaged. The coil packs have no earth but the crank sensor is bolted directly to the block and you cant ask for a better earth than that. Change the crank senor (20 mins job) and i am willing to bet Ant's salary that it starts :)
Click to expand...
That'll be a small bet then!! :D:D:D
 
Have been reading this thread with great intrest.

Think it might be a good idea if you have not done it yet is to send Rick a pm with the summary you did a few posts back. Also might be a good idea to include the pic of the wire that was shorted.

You guys have done a great job so far and i hope you get it running. I have my fingers and toes crossed....
 
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