Fluctuating Idle RPM -Diesel P38

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
kapilamuni said:
So the thrust washer has no impact on the dial gauge reading?
Click to expand...

It depends how you applied the dial gauge. The thrust washer dropping out would effect fuelling not timing. I do not know what you are doing or how you are doing it. If you apply the dial gauge to the piston and load it by a couple of mm then turn engine and find low point on the cam when gauge stops dropping, then zero it, as N2O says if you rotate the engine you will get lift of a little over 2 mm. That does not prove the washer is in place. Basically if you cannot get enough movement towards engine to get at least .95 mm lift on cam you have timing marks on sprockets too far apart. When the timing marks are correct with new chains with .95 lift on cam the retaining studs should be around half way along the slots to allow for further adjustment as chain stretches. And the modulation should be around 45% to 55% with the actual point of injection within a couple of degrees of injection set point. You have none of this. If the thrust washer falls out it alters the relative position of the pressure relief hole in the piston to the control sleeve, the control sleeve position for idle is preset when the pump is calibrated, that would effect fuelling not timing and cause the recent problem you had when you needed to tap the pump centre section to obtain steady idle. You say the car ran well for a long time after you had removed the mid section and replaced it and the lumpy idle only started after you changed the chains, this was corrected by moving the pump mid section. Changing the chains CANNOT change fuelling, only timing. Your stated sequence of events makes no sense to me. The pump maybe knackered with lots of mechanical slop on the X drive i don't know i am not doing the job. All i or anyone else can do is comment on your account of the sequence of events, and to be honest they are not making much sense. I only wish i could be there and help you but unfortunately i cannot. It is very frustrating. ;);)
 
Hope you all can imagine how frustrated I am. With the hot start issue I can't stop the engine wherever I go. If I stop, then need to wait till it cools down, say 1 1/2 to 2 hrs. So every time I go out I take either a kid or my wife with me, so that they stay in the car while I attend to my chores. Even when I go to office, I take special care & make sure parking attendant confirms my position before I shut down. On top of that the car does not pull well now, with AC on I can't get it to go beyond 2000RPM even with the right foot pushed to floor. Only fault shown on Nanocom is 'injection timing out of expected....' . Turbo charger seems to do it's job.
I'm no mechanic. Learned everything from Haynes manuals starting about 30 years ago. Then moved onto work shop manuals, youtube videos & advise from forums like this. With those, managed to change cam belt thrice at each 100K KMs on my small TOYOTA 1.5 Turbo diesel & dismantled(prompted as car stopped moving forward or backward on the middle of the road) its 4 speed auto box (A242L) to change plates in forward n reverse clutches n o-rings. Finally when I sold the car it had done 318,000 KMs & was running fine.
Here there are lot of places to get the Toyota's Denso diesel injection pump serviced, so I did not have to touch it.
But this Rangerover injection pump, even the Bosch agent says can't.
I tapped the center section to get the 'injection quantity current' to show 5-6mg/str about a month ago as advised by N2O and got my idling issue sorted. Now it has moved to 9-10 mg/str automatically but no idling issues yet.
I have spoken to a injection pump service guy (expert on mechanical inj pumps)who agreed to look into the pump, if I remove the top electronic bits and give it to him. Since I have no idea on the internals of the pump,is this a practical way of doing this?
Also, can I use Nancom & move the inj pump body while engine running, to try & get modulation to 50 as this method is completely independent of dial gauge?
 
kapilamuni said:
Hope you all can imagine how frustrated I am. With the hot start issue I can't stop the engine wherever I go. If I stop, then need to wait till it cools down, say 1 1/2 to 2 hrs. So every time I go out I take either a kid or my wife with me, so that they stay in the car while I attend to my chores. Even when I go to office, I take special care & make sure parking attendant confirms my position before I shut down. On top of that the car does not pull well now, with AC on I can't get it to go beyond 2000RPM even with the right foot pushed to floor. Only fault shown on Nanocom is 'injection timing out of expected....' . Turbo charger seems to do it's job.
I'm no mechanic. Learned everything from Haynes manuals starting about 30 years ago. Then moved onto work shop manuals, youtube videos & advise from forums like this. With those, managed to change cam belt thrice at each 100K KMs on my small TOYOTA 1.5 Turbo diesel & dismantled(prompted as car stopped moving forward or backward on the middle of the road) its 4 speed auto box (A242L) to change plates in forward n reverse clutches n o-rings. Finally when I sold the car it had done 318,000 KMs & was running fine.
Here there are lot of places to get the Toyota's Denso diesel injection pump serviced, so I did not have to touch it.
But this Rangerover injection pump, even the Bosch agent says can't.
I tapped the center section to get the 'injection quantity current' to show 5-6mg/str about a month ago as advised by N2O and got my idling issue sorted. Now it has moved to 9-10 mg/str automatically but no idling issues yet.
I have spoken to a injection pump service guy (expert on mechanical inj pumps)who agreed to look into the pump, if I remove the top electronic bits and give it to him. Since I have no idea on the internals of the pump,is this a practical way of doing this?
Also, can I use Nancom & move the inj pump body while engine running, to try & get modulation to 50 as this method is completely independent of dial gauge?
Click to expand...

No you cannot run engine with pump loose. You will never get 50% modulation until you can get .95 mm lift on cam. You need the entire pump testing and calibrating.
 
But he will be checking only the mechanical side. Once dismantled, I guess it needs calibrating. No one here to do that.
 
kapilamuni said:
But he will be checking only the mechanical side. Once dismantled, I guess it needs calibrating. No one here to do that.
Click to expand...
You need to send it away or find one for sale. You are never going to get this right unless you have a known good pump.
Nobody knows more about these than @wammers so you should heed his advice.
 
Hi Guys,
Bought a knackered pump from bay of e. and the seller was kind enough to paint everything in silver colour.
here is a picture. Any guesses on what I'm going to do?

IMG_4425.JPG
 
wammers said:
The woodruff key should be set vertical on pump which means the next port to be injected is to delivery valve number one. The pump should be moved on it's slots to suit the position of the sprocket with the chains set on the bright links and the engine locked at TDC. With chain bright links on marks and engine locked at TDC key way in sprocket should be at about five minutes past the hour. God knows how you have arrived at what you have. Have you put the injector pipes on incorrectly. See this, woodrufff key is vertical number one is the delivery valve with the yellow mark on it, number 5 the one below it, and number 3 the bottom one. Firing order is 153624 pipes should be fitted in that order in an anticlockwise direction looking from rear of pump.



.View attachment 125799
Click to expand...
Mine is different, just noticed it yesterday while changing 2 glow plugs. The yellow tab one is no. 5 and one before that is no 1 though the sequence 153642 remains correct. Checked and found BMW too has the same setup like mine.
 
kapilamuni said:
Mine is different, just noticed it yesterday while changing 2 glow plugs. The yellow tab one is no. 5 and one before that is no 1 though the sequence 153642 remains correct. Checked and found BMW too has the same setup like mine.
Click to expand...

Absolute and utter rubbish. Yours cannot be different. The engine is static timed locked at number one firing with .90 mm lift (old chains) .95 mm lift (new chains) on the number one cam. With the engine locked at TDC number one firing and the timing chain fitted in the correct position on it's marks the woodruff key slot in the sprocket should be almost vertical. The injection pump does not fit in a vertical position on the engine. It is tilted slightly to the left away from the engine. So when turning the injection pump shaft clockwise to number one firing the woodruff key will be slightly to the left of vertical looking at the front of the pump. You either have the chain in the wrong position on the sprockets or you have lost the spacer from the piston when you did the pressure head seal. I know you are trying your best but you simply don't understand what you are being told.
 
wammers said:
Absolute and utter rubbish. Yours cannot be different. The engine is static timed locked at number one firing with .90 mm lift (old chains) .95 mm lift (new chains) on the number one cam. With the engine locked at TDC number one firing and the timing chain fitted in the correct position on it's marks the woodruff key slot in the sprocket should be almost vertical. The injection pump does not fit in a vertical position on the engine. It is tilted slightly to the left away from the engine. So when turning the injection pump shaft clockwise to number one firing the woodruff key will be slightly to the left of vertical looking at the front of the pump. You either have the chain in the wrong position on the sprockets or you have lost the spacer from the piston when you did the pressure head seal. I know you are trying your best but you simply don't understand what you are being told.
Click to expand...
Sounds like the whole thing is 60 degrees out. That would screw things as no.4 would be detecting point of injection incorrectly.
That said, I'd be surprised if it would run like that.
I'm no expert on the diesel but it sounds like a start from scratch job to me!
 
You must log in or register to reply here.

Similar threads

H
Rough idle - discovery 1
Replies
3
Views
291
hi_arshard
H
F
P38 DSE loss of power when driving
2
Replies
33
Views
1K
Mark Piercy
Mark Piercy
ar1g3
P38A P38 rattle at idle
2
Replies
26
Views
3K
roythebus
R
Lej
Fast idle speed (tick-over) + other queries!
Replies
3
Views
260
lynall
L
K
Freelander 1 Freelander 1 problem. Jerks on idle. AND cuts power when high temp.
2
Replies
22
Views
991
Alteredtech
Alteredtech
Back
Top