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1995-2002 Range Rover P38A
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Discussion Starter #1
Hi,
Can someone explain me how the timing solenoid works?
Is it connected to the stop solenoid indirectly?

My car randomly cuts out in the traffic when idling and this was there for last 3-4 months. This happens anytime with or without loading the engine.
Yesterday, checked both these with my Nanocom and noted that when timing solenoid is activated engine struggles. At this moment the 'timing modulation' goes to 93, fully retarding the timing. But stop solenoid when tested just shuts down the engine.
So, assuming the timing solenoid is faulty(though no fault codes in this regard) , disconnected the wiring to it and running now. Should not there be a fault code on timing solenoid.? Yet, the 'timing modulation' moves with increase in RPM. How can this be ? I thought the timing modulation is the adjustment in timing via the timing solenoid.

Other info:
present timing modulation is 4.73 - hot engine idling (too advanced, (I know)since December 2018 after changing the timing chains, this was the only way to get rid of 'hot start' issue. This gives the fault 'Timing out of range' fault.
In-tank fuel pump is not working since about two months. -hope to replace it soon.
 

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Premium Member
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1,257 Posts
Chances are the stalling is due to the failed fuel lift pump. Normally the injection pump will suck fuel through, but if you get air bubbles, pressure could drop enough to stall. Timing seems less likely, that would mainly affect starting. The timing solenoid rotates the cam plate, which regulates the timing of the pressure stroke.
There is also the injection quantity control solenoid, on top of the injection pump. It cuts the injection on overrun, if that sticks it will also cause stalling or non-start.
A lot of good info on https://injectionpumps.co.uk/pdf/bosch_ve_pumps.pdf

Filip
 

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1995-2002 Range Rover P38A
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Discussion Starter #3
Thanx Filip, I thought no one is going to answer.

There are no air bubbles, I'm 100% sure. No leaks from leak-off pipes.
I 've run the car without in-tank pump, about 4 years age for 2-3 months. During that period it never stalled but to start you got turn it for 7-8 cycles, every time. Up to about 80 KMPH it was good then starts to show the effects .


Now the in-tank pump has given up and the RR starts within 1-2 rotations as the timing is too advanced, I guess.
Only other culprit is timing.

Why would it tend to make the engine struggle, when tested via Nanocom?
When the timing solenoid stops responding (as I disconnected the wiring connector) the ECU should know, isn't it?

Thanx for the PDF anyway.
 

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Fuel pumps can fail in different ways. I've ran my Defender TD5 without one for a time, it started easily but lacked power. Others just wont start. Including a P38 DSE I fitted a new pump to. So I wouldn't rule it out, and as it needs changing anyway, start by replacing that. I appreciate you don't see any evidence of air bubbles, but you can never be sure what exactly is going on between the tank and FIP through all the lines and filter etc, when using the car. A blockage in the broken pump or air could cause the stalling.

As for the timing, I can't answer if it should throw a code. The fact that you see the timing modulation change on diagnostics could be just the output of the ECU. It wont necessarily mean the solenoid is reacting to those chances. As evidences when you tried with it disconnected. If you force the timing with the engine running, you will alter the fueling, so it seems logical the engine responds (struggles in your case).
The static timing being a bit advanced will be an advantage in some circumstances (starting) but could cause problems in other conditions.

As an aside, I'm having some problems with FIPs myself. I have 2 on the bench, dismantled, and both seem to have the plunjer stuck in the distribution head. Instead of being able to move and rotate freely...

Filip
 

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1995-2002 Range Rover P38A
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Discussion Starter #5
Got the in-tank pump and will fit it when time allows.
Yesterday, tested the stop solenoid as some tendency to stall shown again. With Nnaocom when activated it didn't stop the engine but almost stopped, kind of struggling to stop. But when switched off with the key, it's a clean stop.

Removed the stop solenoid and re-fitted without the internal plunger. I have a doubt about ECU playing up as both solenoids showed up the same symptoms when tested. Without both solenoids working, Nanocom just displays the message as they are working (when tested for) but at such moment the 'timing modulation' goes back to full retard position (94) .This is corrected only when switch off and restarted.
Will see how it runs in the coming days.
 

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1995-2002 Range Rover P38A
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Discussion Starter #6
It's back. Yesterday, in traffic felt the sudden tendency to stall though it didn't kill the engine. It was like switching off & on again, momentarily. From the web comments, specially the BMW forums, I guess it is the fuel quantity controller circuit in the inj. pump.
Your ideas eagerly appreciated as the cost of replacing the inj pump is prohibitive.
 

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Standard procedure for shutting down the engine is to reduce the injection quantity to 0. The stop solenoid is more like a back-up, a remnant from older pumps without electronic control. But it should stop the engine nevertheless. Could it be leaking at the seat?

Filip
 

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1995-2002 Range Rover P38A
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Discussion Starter #8
It is the symptom that re-appeared. I can shut down/start the engine any time I wish to.
There are no leaks in the fuel system, anywhere.

I disconnected the stop & timing solenoids to verify any mis-behaviour from these.It seems that these are not the culprits.
 

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1995-2002 Range Rover P38A
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Discussion Starter #9
Well, itis more frequent now. with 3-4 times a day. I guess it's time for a recon inj pump.
 
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