V8 fueling/ ignition problem.

Hi all i have a 3.9 v8 petrol/lpg discovery on a 95 M reg ,its being fine until today when i wont start at all, i have removed the plugs and it seems to be fueling heavy on the left hand side of the engine as you look in from the front but the right side plugs are dry and brown as you would expect after run perhaps,any reasons it would fuel one side and not the other, would the mass air flow effect this?
Any help would be great many thanks, Dan

Hi Dan,
I had a similar problem with my 4.0 v8, it seemed to just not start one morning, when the nice AA man came out (lazy i know but it was ****ing down with rain) he disconnected the fuel pump, (by pulling the fuse probably) turned it over for a while then when it was all connected it started fine, apparently it was flooded but i didn't think that would be the case as i didn't spend ages pumping the throttle and cranking the engine! try it and see what happens.

Dan

Hi Dan,

Spooky, mine's just done the same thing! Haven't been able to get it to start since the weekend. I've changed all the electric bits (distributor top, plug leads, coil and rotor ) but to no avail. I'm currently waiting for a genuine LR rotor to arrive as this fault is one of the consequences of cheaper rotors. I've also just extracted the spider (immobiliser) from under the radio support tray on top of the heater unit in the dash and am waiting for the spider by-pass unit. The Disco is renowned for this bit going faulty (according to a very reliable LR company her in Bucks!).

Mine was running rough on gas for a few days prior to not starting at all and the only other probability is the ECU.

So, if anyone else out there has had/fixed a similar problem I would be very grateful to hear about it!

I'll keep you informed as to progress, please let me know if you manage to get yours going again.

Cheers, Mike.

dancarthew said:

Hi Dan,
I had a similar problem with my 4.0 v8, it seemed to just not start one morning, when the nice AA man came out (lazy i know but it was ****ing down with rain) he disconnected the fuel pump, (by pulling the fuse probably) turned it over for a while then when it was all connected it started fine, apparently it was flooded but i didn't think that would be the case as i didn't spend ages pumping the throttle and cranking the engine! try it and see what happens.

Dan

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Thanks Dan i will give that a whirl in the morning.

Thanks Mike for your reply, i have also changed cap , leads , rota arm and other usual suspects, my only worry was why 4 cylinders were wetter than the others sidded on the engine? I will post my progress, thanks again.

is this a common problem with non OE rotor arms then? as mine did exactly the same thing

Hi,
Apparently so. I have had two independent LR experts tell me the same thing now and one is the LPG specialist for Lincolnshire who I have known for twenty years and trust implicitly. Unfortunately he's 150 miles away!

I don't know why the rotor type is so critical, I know the spark has to be clean and powerful (especially on gas) to get the best out of it but every rotor I look at seems very similar to the next one. The OEM one is £25 - £30 and the company sending it to me keep them on the shelf (along with the immobiliser by-pass) as it is such a common problem. Again they are a reputable company who have helped me out before.

It'll be with me on Friday morning so I'll post again when I check it out.

The joys of Landy ownership eh....

Dannn said:

Hi all i have a 3.9 v8 petrol/lpg discovery on a 95 M reg ,its being fine until today when i wont start at all, i have removed the plugs and it seems to be fueling heavy on the left hand side of the engine as you look in from the front but the right side plugs are dry and brown as you would expect after run perhaps,any reasons it would fuel one side and not the other, would the mass air flow effect this?
Any help would be great many thanks, Dan

Click to expand...

Im no exspurt but even if its only fueling on one bank surely it would still fire? Is there a spark at all 8 plugs?

I think it would only fire up if the cyclinders are equal across the engine were as the problem i am having is sided,so it does make an atempt but on one side but its not enough. Yes sparking well i think this could be fueling fault i have read somewhere about a possible ecu fault?

lambda sensor on affected bank sounds good possibility for sooty bank
should still start.

Woo Hoo! I now have a working Disco and the engine sounds fab! What was it??? the bloody immobiliser system hiddden under the radio! My new by-pass plug arrived this morning, I plugged it in and the engine fired in less then two seconds after turning the key. It appears the rough running on LPG has gone too - what a result. And all for less than a tenner! Thanks must go to the guys at Mark Smith Land Rovers in Bicester for correctly identifying the problem, talking me through the immobiliser removal (without taking the dash out) and sending my the part as fast as they did!

that will invalidate your insurance BTW

Hmm, good point! I'll ring my broker in the morning and see what he says. With it being such an old disco it might not make much difference. Fingers crossed.

Thanks for picking up on it!

Cheers,

Mike.

on another line, is the fault on LPG or petrol? is it single point or multi point injection? if the fault is on petrol, are all the injector connections on? timing/dizzy set right? is LPG emulator connected right?

fanatic said:

lambda sensor on affected bank sounds good possibility for sooty bank
should still start.

Click to expand...

lambdas don't work till the engine is running!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
so with that carp out the way fit only gen dealer issue cap leads and rotor and change the coolant injection temp sensor disconnect the battery for 30 min to clear the faults and retry

hi guys new member my name is Ron ,I am from Geelong Victoria Australia ,I have a 94 Disco V8i that i just brought . I also have a non starter as from 3 days ago its a real **** off . After i saw the write up about the immobilizer witch I have ordered from my disco dealer in town. my next question is how did u change it with out pulling apart the dash. could u please let me know as i get my By Pass Plug tomorrow thank u all have fun & be safe

remove the stereo and the fascia around it get a rave manual it is worth the hassel helps out i would also be inclined to replace the coolant injection temp sensor as well as this can cause plenty of faults too