[AZRangeRover]

My Range Rover has an odd problem. It always starts ok but it will occasionally (intermittently and randomly) begin cutting out and stumble and act as if it's running out of gas or has a loose ignition connection. When the problem occurs, it will never actually stall out completely since it will return to idle fine but once I apply any throttle, thats when the problems are really noticed! Sometimes if I floor the throttle through the symptoms, after a little while...with some popping and minor backfiring up through the air cleaner, it seem to help it go back to normal eventually. If I pull over and shut down, it always restarts ok, but the problem is usually still there up until it runs its course and then just goes away as suddenly as it began! I am not sure what triggers this and the fact that it comes and goes randomly is a mystery! I think it must be electrical, possibly distributor related. I have checked everything visibly on the engine and nothing seems noticeably apparent and all is connected. The fuel pump had been replaced recently by the previous owner. I imagine the fuel filter had been replaced at that time as well(?) Does this sound like a fuel issue? Possibly a relay going bad? Has anyone else experienced this before? Please help! I have a complete Range Rover factory shop manual on CD up for grabs for someone who can help me through with this until it's fixed! :drink1:

 

[John C]

You're on the right track, it might be the ignition amplifer (there is a relocation kit for it +/- $200). The ignition amplifiers would overheat and fail. Or it could be the fuel pump or fuel pump connector on the frame by the rear wheel (corroded). Could also be the fuel pressure regulator or even the ignition coil. Just a few things to check.

Good luck,

John C.

 

[Jonesy]

AZ - have you tried cleaning the Plenum chamber? THese things are notorious for causing engine shutdown if not cleaned and kept clean....I had similar problems with mine and this fixed the problem totally!

Good luck.
PS Keep the CD I prefer paper so I bought the manual, but thanks anyway! :buttrock:

 

[hamrendan]

I am with Jonesy for the start up part, but after its warm is where it leads me to believe that is not the problem , Clean that first and hope thats the problem.

Assuming you have changed the Fuel filter in the last 5 years thats probably not it..check the cap and rotor first.. ( its free) Fuel filters $12.00 are cheap. Fuel pump crosses are about $80.00 and are pretty easy to change yourself ( you have to change the connectors usually though) Coil $27.00 for a cheap cross. The truck will buck( like a bronco ) with a bad coil or it won't start at all (BTDT)_

This is a good start, either way i dont' think its too expensive of a problem to sort out

Good luck (CD in drive but thanks for the offer)

 

[OkieRover]

I like all the posts.
Clean the air idler valve first.

If your ignition module has failed it is likely it ate your coil as well. At least that's what mine did....twice!

 

[lonestarrover]

I had 90 RR doing the same thing. Mine would stall out under acceleration and when I would let the throttle go, engine would kick in again. Before you start relocating amp, etc. Change the Distributor cap and rotor. Be sure to use a Lucas cap and rotor or a NAPA parts. A lot of the aftermarket ign stuff is worthless. Fuel pumps either work or not.

 

[AZRangeRover]

Thanks for all the advice everyone!

I'll be sure to go through and check/clean/replace each of those. If it was a bad cap and rotor, it would probably buck and hesitate all the time? Maybe it has a hairline crack? It's worth changing anyways. If it was the ignition amplifier or ignition module (are they the same thing?) and it ate the coil with it...wouldn't it either quit running altogether...like a bad fuel pump or a clogged fuel filter? (The fuel pump was replaced 6 months ago by previous owner. Not sure about the fuel filter though.) The odd thing is that it always starts up fine and runs really well 85% of the time...both with engine warm or cold. The stumbling and bucking only comes on randomly both with engine warm or cold. It's almost as if someone randomly turns a switch from running "good" to running "bad!" When I say bad, it will idle fine...but anything more than 1/8 throttle opening will cause it to buck and cut out as if its about to run out of gas. The intermittent randomness of this problem makes me think of a loose connection or something electrical triggering it to act up. What about the fuel pressure regulator?? That sounds like it could be the possible problem. How can that be tested and what happens when they fail? ..Could it fail and possibly allow fuel pressure in the rail to drop intermittently causing my random symptoms? Could it fail and still allow it to run fine 85% of the time? The mystery continues to elude! I'm just going to have to mull over the RR manual on CD again! Also...How would I go about cleaning the plenum chamber? PS. The air idler valve could be an issue with my occassional high idle at startup, but I don't think it would cause my symptoms. THanks for the picture-I never checked that yet. I will clean it tonight and hope it helps. THanks again for everyone's help with this!

 

[Jonesy]

You should be fine with the advice here....let us know if it doesn't work! OR if it does...:clap:

 

[OkieRover]

If it was the ignition amplifier or ignition module (are they the same thing?) and it ate the coil with it...wouldn't it either quit running altogether...like a bad fuel pump or a clogged fuel filter?

That's exactly what happened on mine. I thought I wasn't getting fuel. But I wasn't getting any spark. Actually my spark was really weak. But before it stopped all together and wouldn't start, it acted just like you describe.

I'm sticking with my air idler valve solution as my recomendation.

I really want to know what it was though, so after you fix it tell us!!!!!
I'm dying to know!

 

[glenncof]

Hey OkiRover, nice picture of idle control valve. Looks new.

 

[OkieRover]

Nope just clean.
I found this miraculous cleaner in the parts store!
It's called Brake Cleaner!
I buy it 6 at a time when it goes on sale for around 1.99 a can. I use it liberally.

:lol:

Any way it works wonders.

 

[Green Achers]

I'll be sure to go through and check/clean/replace each of those. If it was a bad cap and rotor, it would probably buck and hesitate all the time? Maybe it has a hairline crack? It's worth changing anyways. If it was the ignition amplifier or ignition module (are they the same thing?) and it ate the coil with it...wouldn't it either quit running altogether...like a bad fuel pump or a clogged fuel filter? (The fuel pump was replaced 6 months ago by previous owner. Not sure about the fuel filter though.) The odd thing is that it always starts up fine and runs really well 85% of the time...both with engine warm or cold. The stumbling and bucking only comes on randomly both with engine warm or cold. It's almost as if someone randomly turns a switch from running "good" to running "bad!" When I say bad, it will idle fine...but anything more than 1/8 throttle opening will cause it to buck and cut out as if its about to run out of gas. The intermittent randomness of this problem makes me think of a loose connection or something electrical triggering it to act up. What about the fuel pressure regulator?? That sounds like it could be the possible problem. How can that be tested and what happens when they fail? ..Could it fail and possibly allow fuel pressure in the rail to drop intermittently causing my random symptoms? Could it fail and still allow it to run fine 85% of the time? The mystery continues to elude! I'm just going to have to mull over the RR manual on CD again! Also...How would I go about cleaning the plenum chamber? PS. The air idler valve could be an issue with my occassional high idle at startup, but I don't think it would cause my symptoms. THanks for the picture-I never checked that yet. I will clean it tonight and hope it helps. THanks again for everyone's help with this!

OK, I've given you 10 months to report how you fixed this... Well?! :laugh
My 1998 Discovery I is doing the same thing. I'm about to go clean the Air Idle Valve now. It case that doesn't solve my identical problem, I'd like to get to the solution next.:grin

 

[csk_nz]

I had this exact problem on mp 1990 Vogue. Turned out that there was a batch of faulty ECUs in 1990, and an ECU swapped fixed the problem.

 

[ricky_jordan_619]

I'm having a similar issue with my 1991. It starts to buck/misfire between 65-75 mph. new fuel pump, filters, spark plugs, distributor, stepper motor. ran all the tests from the workshop manual and all sensors are within range. she is running rich by the smell and black tipped exhaust. gonna replace the fuel pressure regulator and the ignition coil along with the dist cap and arm. Don't know what else to do.

 

[mikieman]

is it throwing a code... sounds like o2 sensor

 

[signalMTB]

In the Porsche world, this sometimes means valve gaskets.

 

[crazyguy]

I'd love do know what the solution ended up being, even though I know this is an old thread.