Thread: 95 disco 3.9 v8 running like a dog

Originally Posted by petey0505

Hi Guys,

This is my first post so I apologise in advance if i leave any info out.

Recently purchased the above vehicle which had issues in starting and running but got it cheap so I took a risk. The vehicle does not like to start easily at any temperature. You can crank the motor with no throttle and it will not fire up. Give it a little throttle and eventually it might start but sounds like it is running on 4 cylinders. It will sometimes then stall and at other times if you can keep it running by pumping the throttle it will clear itself after 10-15 seconds and start firing on all cylinders.

I did find that it would generally start ok by holding the throttle flat to the floor and cranking for 5 seconds or so. However once you got it running it idles rough and has a huge flat spot around 1500 revs that makes driving it very uncomfortable. The idle also fluctuates somewhere between 600 and 1500 rpms.

Work done to date includes

Fuel pump replaced with new
Fuel filter replaced with new
Idle Air control valve replaced with new
Fuel regulator replaced with secondhand unit

All vacuum hoses checked and replaced as necessary. All the above made no difference to the behaviour of the vehicle. Finally decided to take it to my mechanics to no avail. They could not find any fault other than to say the coolant temp sensor was an open sensor and may not be reading right.

After two weeks with them and no answer the vehicle was sent to a supposed landrover expert mechanics shop. Spoke them today at length and they are none the wiser either. Apparently there are no codes showing from the computer. Their own computer readings when the vehicle was running indicated that the temp sensor and MAF appeared to working OK. Fuel pressure was 35psi and supposedly OK. They believe the vehicle is running lean which maybe explains the funny starting issues but cant remember how they came to that conclusion.

Can anyone help please. They are leaning towards a buggered ECU but don't have a spare one to swap over to test it.

In my searching of this (and other sites) I have been unable to find a similar starting issue where it runs on half the cylinders.

Any help would be muchly appreciated.

Thanks in advance.


Pete

hi.
i have a 94 disco v8.
i had problems with it stalling very regularly.
once it stalled it wouldnt start for about 5 mins til it cooled down abit.
it stalled on fraser island at xmas and i was stuck there for 3 extra days trying to get it going.
it turned out to be the magnet inside the distributor.
it had cracked in half and upset the spark gap so the car wouldnt fire.

its not exactly the same symptoms but may be worth looking at.

These replacement distributor kits are very affordable and, according to reports on other forums, work extremely well.

Rover 3.5 3.9 4.2 V8 35D Distributor with Lucas Module & DLB198 Ignition Coil Rover 3.5 3.9 4.2 V8 35D Distributor with Lucas Module & DLB198 Ignition Coil [D2M11 & CE5 & R5] - £139.99 : Electronic Ignition, Home of the Powerspark electronic ignition