3.5 EFi Dies for a day!!

[Jaguarman]

Hi,

I have a fault with my Range Rover. It is running 1987 3.5 EFi gear. Twice now, it has died on me whilst out. Both times, it won't restart. If left for 2/3 minutes, it will fire on one cycle, and then stall again. Trying to restart, it just cranks. Leave it another few minutes, and it does the same again!
The first time it did this, we found that the injectors were not being controlled by the ECU. I pulled it back to my workshop, and fitted a substitute ECU. Away she went!
The running gear has been fitted to a 1972 Range. Tracing through the wiring diagrams, I found a ballast resistor that should have been inline with the pulse wire from the constant energy unit to the ECU. With this replaced, I have covered 400 or so trouble free miles, thinking that I had found the cause of the blown ECU. Until yesterday!!
Half way through a green lane, it did it all over again!

Frustrated, I dragged it home.....again....and left it.
This morning, it has fired up and runs lovely again!!!!!
So, chances are, my last ECU was fine. If I had left the car overnight, it may have fired up fine.
What the heck is this???!!!!!
Any ideas will be greatly appreciated!
I use the truck for my business, pulling in dead Jags. THANKFULLY, it has yet to do this to me whilst pulling a car in.....but it's only a matter of time!!!

Cheers,
Keith

[Ebooters]

Hi it sounds like the ingnition amp on the distibutor
this sends the trigger signal to the injectors as well as triggering the coil

[Simon B]

Hi, I had this kind of fault on a 1990 3.9 EFI. I changed the amplifier module first, then the dist. cap, coil, ECU and the airflow meter! Cost loads of money! By sheer chance, I put a really old rotor arm in the distributor (I`d recently replaced it with a new one), and the problem was gone. Turns out that this is a really common fault on them. The rotor insulation breaks down and it earths through the post, but it often won`t happen when the engine is really cold (jumping the cap in the spark plug easier when cold? Still not sure). Anyway, cheap rotors are the cause, which my new one was. I was told to buy only genuine Lucas, and even some of those are dodgy.
I would buty a couple of new ones, and see what happens. Good luck!
Simon B

[Jaguarman]

Thankyou both for your replies.
Things have progressed - a little!!
I have replaced the thermotime switch, coolant sensor, and aux. air valve with known good used items.
The car has never started very well once warm, so I though what the heck - lets swap some parts out as i have them!
With this done, it starts up really well - everytime. It has yet to die on me....the way it did at the start of the post anyway!!
NOW....it runs really well, until up to full temperature, and it will start to drop out cylinders, cough, backfire through the inlet, and eventually die!! Give it 20 mins and it will be fine again

Any ideas, or matches??!!!!

Cheers,
Keith

[Simon B]

Go on - give a new rotor arm a go! It won`t cost much.
SimonB

[Jaguarman]

Originally Posted by Simon B

Go on - give a new rotor arm a go! It won`t cost much.
SimonB

Will do boss Keep you all posted!!!

[Jaguarman]

Originally Posted by Jaguarman

Will do boss Keep you all posted!!!

Well, its 5 dyas now with a new cap and rotor, and it has yet to mess about!! I will, again - keep you posted!!!!

I may venture down a green lane soon - with a support vehicle

[Simon B]

Go on, admit it, it was the rotor! I wouldn`t be able to resist putting the old one in to see if the fault re-occurs. When mine did this, I swapped them several times before I was convinced, then someone on another forum told me it was common.
Simon B