Range Rover P38 diesel injector pump problem

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Simply put, when the throttle pedal is pressed the ECU receives a signal and positions the quantity servo to service that rpm/power request. The feedback pot then sends a signal telling the ECU the requested position has been achieved. If the feedback pot sends the wrong signal or the wiper loses contact with the track, sending no signal, the ECU drops the emergency stop solenoid to stop the engine. Fuel flow fault means the pot is telling the ECU that there is a different servo position than that requested. If that continues you will need to get the pump refurbished.

Thanks, Wammers.

Just for my benefit, will it be looking at the throttle at idle? Presumably it is just sat there at 0%? If so, why are his values all over the shop at idle?
 
Yep.

Could be that i was not idling all of this logging. Reved the engine at some of the save logs.
But it is still the limitation that you cannot see more parameters at the same time. E.g. throttlepisition and crankspeed at the same time as the fuelling parameters.
Is there not a way to log all of these at the same time. would be much more useful data.
Will be doing a new test tomorrow.

And I get Your point Wammers, Will be looking for a refurbished pump. Do these have to be coded to the ecu or is it normal dieseltiming?
 
Yep.

Could be that i was not idling all of this logging. Reved the engine at some of the save logs.
But it is still the limitation that you cannot see more parameters at the same time. E.g. throttlepisition and crankspeed at the same time as the fuelling parameters.
Is there not a way to log all of these at the same time. would be much more useful data.
Will be doing a new test tomorrow.

And I get Your point Wammers, Will be looking for a refurbished pump. Do these have to be coded to the ecu or is it normal dieseltiming?

No just the same part number as the old one.
 
Thanks, Wammers.

Just for my benefit, will it be looking at the throttle at idle? Presumably it is just sat there at 0%? If so, why are his values all over the shop at idle?

At idle with throttle pot at less than 9%, engine speed is controlled by the ECU referencing CPS to maintain 750 RPM + or - 50. Fluctuations will occur as loads are applied and removed. Eg steering inputs, alternator loads. If load is removed the RPM will rise above 750 fuel is then reduced to return to 750. If a load is applied as mentioned fuel is increased to maintain 750. So there will always be fluctuations. Loss of contact with the feedback pot will cause hunting and or stall. If engine RPM drops below 500 RPM due to load the engine will stop.
 
Yep.

As for the loss of contact from the pot. You reckon it is worn out in certain places? As it happens on both idle and 1800 rpm, but not on higher rpm.

Just out of curiosity. Why is it that it seems to be working fine after it has been stopped for a while and engine is cold?
Today I moved the car 10 km without a misfire. Idle was stable at junctions. Power was ok and would not have noticed anything wrong if I did not know it existed.
 
Yep.

As for the loss of contact from the pot. You reckon it is worn out in certain places? As it happens on both idle and 1800 rpm, but not on higher rpm.

Just out of curiosity. Why is it that it seems to be working fine after it has been stopped for a while and engine is cold?
Today I moved the car 10 km without a misfire. Idle was stable at junctions. Power was ok and would not have noticed anything wrong if I did not know it existed.

Just keep watching it then. Intermittent things are hardest to nail down.
 
When my FIP started acting up it only did it when warm. Guess in that case the expansion when hot was enough for the tolerances to go far awry.

Had the same with a camshaft sensor on another car, now I think about it. Electronics don't seem to like heat.
 
Wouldn't worry about using the Nanocom viewer. Excel is better.

I've put your results in the zipped Excel file below together with a top level comparison to mine. View attachment 139421

Your values are way more variable than mine (although your timing modulation is pretty good in that it is around 50%). The injector set point and actual should be within 0.5 degrees of each other but your keep dropping out. The fuel is all over the place too.

View attachment 139422

What this means in practice I don't know! Need someone like @wammers for that.

If it were me I'd start with the lift-pump check from the Technical section. It is easy and free to do. Plus the in-tank pump is relatively cheap.

My set point is always 1.8 degrees. Yours is all over the place. Not sure why that would be but when it changes that's when your timing modulation goes out and the fuelling suffers. This was with a fully warm engine, right? The higher values would indicate a cold engine. Maybe the temperature sensor is acting up? If you go into the General screen I think you can record the temperature inputs?

After that I'd be looking at that injector set point. I'm not sure where it is getting that reading from? Wammers will know. I think it might be the needle sensor in the number 4 injector. Has the #4 injector been touched or got wet? If that #4 sensor is damaged then that will cause issues. I cannot remember if the car will run on default values with it unplugged? Maybe someone on here like @tomcat59alan would know if it is worth a try.

Given past history I'm leaning towards #4 injector but I think we need a guru's view. Hope that helps a little.
Sorry been away, but not to the sun. That's next week.:D. The engine will run with number 4 injector unplugged.
 
So now the car has run smoothly the last 8 days or do. But today after starting from cold engine, it started acting up again. Frequently cutting engine for half a second.

So I stopped, turned off the ignition. Connected my nanocom and started up. Then it runs fine again. Perfect....
 
So now the car has run smoothly the last 8 days or do. But today after starting from cold engine, it started acting up again. Frequently cutting engine for half a second.

So I stopped, turned off the ignition. Connected my nanocom and started up. Then it runs fine again. Perfect....

I would suggest you do not start engine with Nanocom switched on. If you need to restart with Nanocom attached, switch it off, then start and switch Nanocom back on.
 
Presumably to prevent damage to the nano' then. Makes sense, incase the risk of any electronic spikes to the unit. Maybe? :rolleyes:

I got one of the evaluation models a few weeks before they went on sale to the public. Maybe it was to protect that. But sure i have read it somewhere in the bumff.
 
How come wammers, will it damage the nano' or interfere with Ecu signals?:eek:

I think it is because power gets cut to the diag socket so it like a hard reset on the Nanocom. Probably OK if you're not in any module but possibility of corruption if it is writing at the time.

I suspect inside it is just a little £20 Aduino single processor unit running a stripped Linux OS. The average Smartphone would blow the pants off it. Pity he hasn't ported it to Android really, especially as Android is basically a different flavour of Linux at its core.
 
Back
Top