P38 2.5 Inj Pump modulation issue.

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markav8r

Member
Posts
67
Location
Northern Ireland
I left my 2001 P38 2.5 to an independent Landrover Garage to have the injection pump replaced with a factory overhauled unit due to the original leaking past the seals. It was running fine otherwise. After swapping pumps the car cuts out, and the garage suggested that it was a faulty pump. They suggested having the original overhauled, so I let them send it away. After fitting the overhauled original pump, the engine continues to cut out especially when on the overrun. Thanks to this forum I checked the "modulation" and discovered it was between 4% to 7%.instead of the 45 to 55%. I have sourced the timing pin, and they claim that the pump is timed correctly (although they weren't using the exact crank locking pin). The garage suggested various possible causes, all of which they have replaced now (Crank sensor, even temperature sensors) Injector 4 has also been changed. Is it possible that the garage are using an incorrect timing point on the flywheel? (I have now also bought the crank locking pin and left it with the garage). Or that the pump sprocket has been knocked out a link (one possibility they suggested). The car starts and runs OK, albeit with far less power than it had previously, it just cuts out regularly on each trip. I've been without the car for many many months due to this.
 
I left my 2001 P38 2.5 to an independent Landrover Garage to have the injection pump replaced with a factory overhauled unit due to the original leaking past the seals. It was running fine otherwise. After swapping pumps the car cuts out, and the garage suggested that it was a faulty pump. They suggested having the original overhauled, so I let them send it away. After fitting the overhauled original pump, the engine continues to cut out especially when on the overrun. Thanks to this forum I checked the "modulation" and discovered it was between 4% to 7%.instead of the 45 to 55%. I have sourced the timing pin, and they claim that the pump is timed correctly (although they weren't using the exact crank locking pin). The garage suggested various possible causes, all of which they have replaced now (Crank sensor, even temperature sensors) Injector 4 has also been changed. Is it possible that the garage are using an incorrect timing point on the flywheel? (I have now also bought the crank locking pin and left it with the garage). Or that the pump sprocket has been knocked out a link (one possibility they suggested). The car starts and runs OK, albeit with far less power than it had previously, it just cuts out regularly on each trip. I've been without the car for many many months due to this.
It is possible to get the locking pin in the wrong place and using the correct pin is essential. The timing is wrong, I assume you checked the modulation at 2K rpm? If you have diagnotics that gives live readings of the modulation, you can use that to get the timing near enough tapping the pump gently round.. Sounds like the garage is useless.
 
It is possible to get the locking pin in the wrong place and using the correct pin is essential. The timing is wrong, I assume you checked the modulation at 2K rpm? If you have diagnotics that gives live readings of the modulation, you can use that to get the timing near enough tapping the pump gently round.. Sounds like the garage is useless.

Modulation is checked at idle with engine warm not at 2000 rpm. ;)
 
I left my 2001 P38 2.5 to an independent Landrover Garage to have the injection pump replaced with a factory overhauled unit due to the original leaking past the seals. It was running fine otherwise. After swapping pumps the car cuts out, and the garage suggested that it was a faulty pump. They suggested having the original overhauled, so I let them send it away. After fitting the overhauled original pump, the engine continues to cut out especially when on the overrun. Thanks to this forum I checked the "modulation" and discovered it was between 4% to 7%.instead of the 45 to 55%. I have sourced the timing pin, and they claim that the pump is timed correctly (although they weren't using the exact crank locking pin). The garage suggested various possible causes, all of which they have replaced now (Crank sensor, even temperature sensors) Injector 4 has also been changed. Is it possible that the garage are using an incorrect timing point on the flywheel? (I have now also bought the crank locking pin and left it with the garage). Or that the pump sprocket has been knocked out a link (one possibility they suggested). The car starts and runs OK, albeit with far less power than it had previously, it just cuts out regularly on each trip. I've been without the car for many many months due to this.

The garage don't know what they are doing. Engine cutting out whilst slowing down is usually a quantity servo fault. But get the static timing done properly first. They have wasted your money on all those bits that were not needed.
 
At 4-7% it won't take long to go out of range and then the car will cut out. Read RAVE, or get the garage to. IT is pretty easy to follow, even for a beginner like me. Chain stretch usually causes a modulation up above 80-90% so don't think it is chain stretch. Got to be adjusted wrong. You need to get the lift just right on the dial-guage. Sometimes it can move as you tighten so you need to check it 2 or 3 times before reassembling all the injector pipes.
 
That's what I thought, but you said 2K in an earlier post so I changed my reference. Must have been a bad day:D

Don't think i would have ever said check modulation at 2000 rpm as i definitely know that not to be correct. Everybody has a bad day now and again though. ;):D
 
At 4-7% it won't take long to go out of range and then the car will cut out. Read RAVE, or get the garage to. IT is pretty easy to follow, even for a beginner like me. Chain stretch usually causes a modulation up above 80-90% so don't think it is chain stretch. Got to be adjusted wrong. You need to get the lift just right on the dial-guage. Sometimes it can move as you tighten so you need to check it 2 or 3 times before reassembling all the injector pipes.

The static is to far advanced. Much to far advanced.
 
If they have never done this job before they must follow the correct procedure for pin location and timing set up using a DTI. There are two timing pips, one 40 degrees before the TDC pin hole and one 20 degrees after it. It is easy to get hung on one of those which will put static miles out. With the pin correctly inserted the engine should be immovable in either direction. The pump is set to 0.9 mm cam lift after having followed correct procedure for zeroing DTI and then inserting timing pin.
 
I have no internet at home anymore. So I only go online when out and about. Looks like there isn't so much action for the P38s on here these days ... apart from Pete's ongoing EAS issues.
There's not much action because we've nearly fixed them all:rolleyes:.
Have you not payed your bill grrr rrrro_O:p
 
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If they have never done this job before they must follow the correct procedure for pin location and timing set up using a DTI. There are two timing pips, one 40 degrees before the TDC pin hole and one 20 degrees after it. It is easy to get hung on one of those which will put static miles out. With the pin correctly inserted the engine should be immovable in either direction. The pump is set to 0.9 mm cam lift after having followed correct procedure for zeroing DTI and then inserting timing pin.
Damn your good man, i am convinced you helped design these thingso_O;)
 
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