MGBGTV8
Active Member
- Posts
- 690
- Location
- Alfreton, Derbyshire
Here we go again, lads!
My '94 V8 Disco has spat it's dummy out... Went out this morning to nip out for some bread. Started the Disco and it was running very rough - lots of misfiring. Switched it straight over to gas and it ran great. Better than usual come to think of it...
Bought my bread and came back to the truck. Wouldn't start. Bum.
Walked home and got my other half to run me up with a can of petrol on the off-chance it might be out and the gauge was telling lies.
Started it up on the 2nd or 3rd attempt and again was running rough as a badgers backside.
Once again I switched straight onto gas and ran it home and parked it up.
It now won't restart.
There seems to be enough fuel getting through such that when she's turned over the engine will catch and then cut out immediately.
When the key is turned the fuel pump primes and cuts out after 4 seconds like it's supposed to.
If I get an assistant to turn the engine over I can hear the fuel pump re-engage as the engine cranks over. So, presumably that rules out the fuel pump relay?
When the fuel pump has primed the system, if I depress the Schrader valve with a screwdriver there is a little squirt of petrol that dribbles away to nothing.
If the key is turned such that the engine cranks over there is a continuous dribble from the Schrader valve.
There is a nice strong spark.
I have eliminated the ignition system completely in that I have got an assistant to turn the engine over such that it catches. A gentle mist of carb cleaner in the mouth of the MAF will allow the engine to idle.
That says to me that the injectors aren't doing anything...
The other thing I believe I've eliminated is the idle control valve - it still clicks and makes noises when the key is switched off.
I've spent the evening trawling through the interweb trying to find something to work from to start diagnosing the problem a little more. Unfortunately, I lost all my Rover EFI stuff when the last computer went pop.
So far I've managed to come up with the two PDF's that I've uploaded. However, if anyone has a link or a PDF of something D1 (single alarm button) specific that'd be really helpful.
As I see things, the next thing to do is:
1) Buy a fuel pressure tester and check that the fuel pressure is @ 2.5 bar when primed. (Presumably that figure should be the same when cranking? or is that a red herring?)
2) Start working through the two PDF's I've found.
First Question... should the mains relay and the fuel pump relay be identical? They are on this car.
Second Question: Given all the above info, has anyone had any similar symptoms to deal with? Is there anything blindingly obvious I'm forgetting about?
Third Question:
Where does my ECU live???
My '94 V8 Disco has spat it's dummy out... Went out this morning to nip out for some bread. Started the Disco and it was running very rough - lots of misfiring. Switched it straight over to gas and it ran great. Better than usual come to think of it...
Bought my bread and came back to the truck. Wouldn't start. Bum.
Walked home and got my other half to run me up with a can of petrol on the off-chance it might be out and the gauge was telling lies.
Started it up on the 2nd or 3rd attempt and again was running rough as a badgers backside.
Once again I switched straight onto gas and ran it home and parked it up.
It now won't restart.
There seems to be enough fuel getting through such that when she's turned over the engine will catch and then cut out immediately.
When the key is turned the fuel pump primes and cuts out after 4 seconds like it's supposed to.
If I get an assistant to turn the engine over I can hear the fuel pump re-engage as the engine cranks over. So, presumably that rules out the fuel pump relay?
When the fuel pump has primed the system, if I depress the Schrader valve with a screwdriver there is a little squirt of petrol that dribbles away to nothing.
If the key is turned such that the engine cranks over there is a continuous dribble from the Schrader valve.
There is a nice strong spark.
I have eliminated the ignition system completely in that I have got an assistant to turn the engine over such that it catches. A gentle mist of carb cleaner in the mouth of the MAF will allow the engine to idle.
That says to me that the injectors aren't doing anything...
The other thing I believe I've eliminated is the idle control valve - it still clicks and makes noises when the key is switched off.
I've spent the evening trawling through the interweb trying to find something to work from to start diagnosing the problem a little more. Unfortunately, I lost all my Rover EFI stuff when the last computer went pop.
So far I've managed to come up with the two PDF's that I've uploaded. However, if anyone has a link or a PDF of something D1 (single alarm button) specific that'd be really helpful.
As I see things, the next thing to do is:
1) Buy a fuel pressure tester and check that the fuel pressure is @ 2.5 bar when primed. (Presumably that figure should be the same when cranking? or is that a red herring?)
2) Start working through the two PDF's I've found.
First Question... should the mains relay and the fuel pump relay be identical? They are on this car.
Second Question: Given all the above info, has anyone had any similar symptoms to deal with? Is there anything blindingly obvious I'm forgetting about?
Third Question:
Where does my ECU live???
