Range Rover surging ?

[VladTepes]

RR 1995 LSE 3.9l V8

Seems to be surging or cutting out and back in especially at speed (at least I noticed it more on the highway, might just have been that there were fewer other distractions).

I'm thinking it might be:
a) interruption to spark ?

However when I run the engine up and down in revs in neutral it seems to be running smoothly through to 3000 revs.

b) gearbox ?

Don't know how these work - is there some sort of electronic signal from the ecu that may be at fault ? Perhaps it's low on fluid which I'll check soon. On that - should trans fluid level be checked warm or cold ?

c) something else ?

Anyone have any ideas or experienced a similar thing ? I;d love some iea of how to approach it because I can;t get the thing in MR Auto until next Thursday and I;d like it fixed ! Also have no desire to spend any more money that absolutely necessary.

[incisor]

there could be soooo many things showing those symptoms.....

check your fuel filters, did it start just after fueling up? blocked filter or dirty fuel

ignition module can cause these symtoms on a disco, do rangies have the same setup ?


fuel would be my first look and see

[Pedro_The_Swift]

mine surges all the time,,,





when Mrs Pedro drives---:D

[incisor]

could be a speed sensor as well, they make the vehicle behave like that as well i am told...

[harry]

vlad you might like to get the temp sensor checked, like i put up with my disco doing the stop for ages until it really pooped me and got worse. initially stopping whenever it wanted to, long story, then it got to really bad fuel consumption, no i mean really bad!
so off to ricks 4wd - they changed a temp sensor and its been a good girl ever since.
which temp sensor i hear you repeating,
nup , dunno, i couldn't even find it when i got home from ricks,
and next day i got it all muddy, but a water temp jigger i think,

[harry]

so outlaw, what happened to my banner, it all looks like gobblygook?

[George130]

First suspect would be fuel.
Auto box should be checked with engine running and in neutral (Otherwise it was park). Best done at normal opperating temp (Not ultra HOT or COLD).

[walker]

I would be guessing fuel as well.

Mine did it a lot after I put the bigger motor in. Unlike yours I am running carby but the problem was that it was running lean. This means when you put your foot down everything is ok but if you are cruising at speed and just accelerate a little bit it surges.

Fuel filter
ECU problem
fuel injection problem

I ended up taking it to a tuning place and he found the problem and fixed it and did a full tune for a set price of $88

[PhilipA]

typical of worn TPS ( throttle position sensor)
regards Philip A

[discoute]

Check the air flow meter and hoses have no loss of vacum ie holes or splits, clamps are tight. Throtle position sensor sounds like it could be a problem.

ECU will try to compansate for any loss of air velosity thru the air flow meter. Does it run rich, can you smell this from the exhaust ?

glen