- Posts
- 19,297
- Location
- Buckinghamshire, UK. ('95 DT)
At 94% modulation there is almost no pressure on piston?
Fluctuating Idle RPM -Diesel P38
- Thread starter kapilamuni
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
- Posts
- 58,170
- Location
- Preston Lancs.
Yes i know.
kapilamuni
Active Member
- Posts
- 550
Will check the static timing again, later.
Have to keep the bonnet closed, at least for few more days.
Have to keep the bonnet closed, at least for few more days.
- Posts
- 58,170
- Location
- Preston Lancs.
There is a large hole well before the 40 degree timing pip and one just after the 20 degree pip if engaged in those the engine could be move back and forth in the hole and the engine would never start if timing was done engaged in those. There is a timing peg 20 degrees after the TDC position that is easy to get hung up on. If hung on that the engine could be moved anticlockwise but not any further clockwise. To get a start if timed hung on that the pump top would have to be moved fully towards the engine and he would have more or less what he has now.. For static the timing and cam timing pin MUST be engaged in the TDC hole 40 degrees after the first timing pip and 20 degrees before the next one so that the engine is locked solid and cannot be moved in either direction. It is taken for granted that cam timing was done with pin in correct position. And that static timing was done later. I seem to recall him saying pump had been moved after all was reassembled. If static was correct with new chains pump securing studs should be mid way along the slots in the pump flange. Moving pump top away from engine retards timing towards engine advances it. With 94% modulation at warm 750 idle it is pretty obvious the static is wrong. Modulation reference static should only be read at 750 RPM idle warm engine, modulation at any other engine speed is irrelevant.
Last edited:
kapilamuni
Active Member
- Posts
- 550
Hi Guys, I'm back.
Going to redo the static timing & need few clarifications.
When the no 1 cam lobe in vertical position (90 deg before TDC) means, perpendicular to ground or cylinder head surface ?
(this is due to engine is fitted with a slant & rocker cover top surface is parallel to ground/floor.)
I had to replace the leaking cam cover gasket today(fitted new in Dec'16, you know ---part) and noted that cam locking tool has about 5mm gap at the intake side.
Since I fitted new chains in Dec last year and now done about 6000KMs, should I correct it to zero space? The RAVE says for cars done more than 20000 miles (32,000 KMs) need to have that gap maintained.
Here is a picture of flywheel & can someone point me the exact TDC locking pin hole?
Going to redo the static timing & need few clarifications.
When the no 1 cam lobe in vertical position (90 deg before TDC) means, perpendicular to ground or cylinder head surface ?
(this is due to engine is fitted with a slant & rocker cover top surface is parallel to ground/floor.)
I had to replace the leaking cam cover gasket today(fitted new in Dec'16, you know ---part) and noted that cam locking tool has about 5mm gap at the intake side.
Since I fitted new chains in Dec last year and now done about 6000KMs, should I correct it to zero space? The RAVE says for cars done more than 20000 miles (32,000 KMs) need to have that gap maintained.
Here is a picture of flywheel & can someone point me the exact TDC locking pin hole?
- Posts
- 19,297
- Location
- Buckinghamshire, UK. ('95 DT)
From memory that is the starting point so shouldn't matter that much. I did it with the lobe pointing vertically upwards from the floor but it doesn't have to be exact as that's when you push the locking pin in. It should be pretty tight. Then you start turning the engine clockwise little by little and trying to jam the pin in all the time. The first hole you come to is TDC. Miss it and you have to go round again.
- Posts
- 58,170
- Location
- Preston Lancs.
Cam lobe vertical in relation to the engine. = 90 degrees BTDC. At that point the DTI is inserted into the pump and set with 2 mm or so on it. Continue turning engine clockwise until the needle stops falling. At this point zero the DTI. Continue slowly turning engine until cam lobes are approaching flat across the top and engage locking pin. Engine MUST be locked solid so it cannot be turned in either direction. Read the DTI and adjust pump position to give 0.95 mm lift on cam. Last movement to set this TOWARDS engine. On the flywheel shown the lock pin hole is the one towards the outer edge at around twenty past the hour. There should be a timing pip 40 degrees before it and another 20 degrees after it in the direction of engine rotation.
kapilamuni
Active Member
- Posts
- 550
Revisited static timing. Everything is set as told, I can't get 0.95mm lift on cam. I'm unable to push the FIP towards the engine any more & the dial gauge shows 0.71mm at that point. But if I push it back away from the engine, I can get 0.95mm lift (after passing 0 position in dial gauge) but the pump is more towards the other end where,its said to be highly retarded timing. In both locations my modulation is around 93 and the latter position giving shaky idle with lots of white smoke.
Anyway, set it to max position towards the engine & using the car now. Other than the hot start issue (even with hot start kit fitted) car seems fine.
I really need help to get over with the 'hot start' issue.
Anyway, set it to max position towards the engine & using the car now. Other than the hot start issue (even with hot start kit fitted) car seems fine.
I really need help to get over with the 'hot start' issue.
- Posts
- 58,170
- Location
- Preston Lancs.
When you did the chains the bottom one was fitted incorrectly with thirteen links between the timing marks instead of twelve. When the engine is locked at TDC number one firing a raised link on the chain should be engaged on the crank sprocket mark. Including and counting from that link, the twelfth raised link from that to the right should be engaged on the pump sprocket mark. Think you may find if you strip it, that with engine locked at TDC number one firing, if a raised link is set on crank sprocket mark, you have the pump sprocket mark against the next link from the twelfth raised link, which will be a depressed link or you have it on the thirteenth raised link. The pump sprocket is one or two teeth out. That is why you cannot set pump correctly. This will not effect cam timing, that is set separately, but the pump sprocket is in the wrong in initial position.
Last edited:
dubbleRR
Well-Known Member
- Posts
- 1,018
- Location
- highlands of Scotland
+ 1 On that,white smoke is at least one tooth retarded on the pump
kapilamuni
Active Member
- Posts
- 550
The new chain(& also the old one) came with gold coloured links for crank & inj pump sprockets. I'm certain that it was set correctly & never turned the engine counter clock wise, but only a few mm to check whether it turns after inserting the locking pin in flywheel.. But when the chains were fitted, the pump was at the position , fully pushed towards the engine. On that occasion, I queried whether to get the pump centered on it's fitting bolts.
See post #33 on
https://www.landyzone.co.uk/land-rover/timing-chains-diesel-p38.308324/page-2.
Could this be a reason for the issue?
Forgetting the reason for it, any chance I can correct it without removing the whole lot? Can I get the pump out & reinsert after rotating the shaft sufficiently?
- Posts
- 58,170
- Location
- Preston Lancs.
Cannot be corrected other than by fitting bottom chain correctly. As it is you will never set static timing and get correct modulation. It should have been pretty obvious that the pump needed slackening off and be turned away from the engine on it's adjustment slots to line up the timing marks. If the pump had been moved fully towards the engine to compensate for stretched chains then it needs moving back away from the engine to enable fitting of new un-stretched chains. Seems you have some work to do.
Last edited:
kapilamuni
Active Member
- Posts
- 550
The photo shows the bottom chain fitted. The inj pump chain link is set on the mark. Crank link though not visible, was set on the coloured link too.
Just ignore the home made tensioner tool.
I doubt the bottom chain setting to be wrong. But when I tried to get the keyway aligned, I had to rotate the pump shaft. May be at that point, without rotating the pump shaft, I should have rotated the whole pump by loosening the mounting nuts. In that context can I do the following;
1. get the timing on TDC & insert the locking tool in flywheel to verify TDC.
2. Remove locking tool and rotate engine clockwise about 1 cm at the crank pulley .
3. remove injection pump using the locking tool on the sprocket.
4. turn pump shaft clockwise about 2 - 3 mm or as required for next step..
5. refit the pump , aligning shaft key.
6. re set static timing the normal way.
your ideas please. I really really can't get back on removing head, sump & timing cover etc etc.
Just ignore the home made tensioner tool.
I doubt the bottom chain setting to be wrong. But when I tried to get the keyway aligned, I had to rotate the pump shaft. May be at that point, without rotating the pump shaft, I should have rotated the whole pump by loosening the mounting nuts. In that context can I do the following;
1. get the timing on TDC & insert the locking tool in flywheel to verify TDC.
2. Remove locking tool and rotate engine clockwise about 1 cm at the crank pulley .
3. remove injection pump using the locking tool on the sprocket.
4. turn pump shaft clockwise about 2 - 3 mm or as required for next step..
5. refit the pump , aligning shaft key.
6. re set static timing the normal way.
your ideas please. I really really can't get back on removing head, sump & timing cover etc etc.
- Posts
- 58,170
- Location
- Preston Lancs.
No you cannot, the woodruff key slot in the pump sprocket is in the wrong position because the bottom chain was not fitted correctly. ONLY fitting the bottom chain correctly will solve your problem.
- Posts
- 58,170
- Location
- Preston Lancs.
On the pump sprocket there are two timing marks, one has 4 against it, one has 6 against it. It MUST be set against 6 with engine locked solid at TDC. Anywhere else is placing the pump keyway in the wrong position, nearer to the engine than it should be and not allowing enough movement of the pump towards the engine to achieve static timing. It should have been set against the 6 mark. 4 is for four cylinder engines 6 is for six cylinder engines. Set like that you will NEVER get the static timing correct. The timing case can be removed without removing the cylinder head. But the sump will have to be dropped a little.
Last edited:
dubbleRR
Well-Known Member
- Posts
- 1,018
- Location
- highlands of Scotland
Im i right in thinking ,if the bottom end timing is wrong on the pump ,then cam timing is wrong with the bottom timing,because the cam drives off the pump sprocket...that would cause rough running ..I think to much i think
- Posts
- 58,170
- Location
- Preston Lancs.
Im i right in thinking ,if the bottom end timing is wrong on the pump ,then cam timing is wrong with the bottom timing,because the cam drives off the pump sprocket...that would cause rough running ..I think to much i think
No cam timing is separate.
kapilamuni
Active Member
- Posts
- 550
It was placed on 6, where i hv put a dab of correction fluid., visible in the picture. IIRC, 4 and 6 are about 2 links apart, and I doubt the car would even start
when timing set at 4. Anyway, I'm in deep trouble now.
when timing set at 4. Anyway, I'm in deep trouble now.
- Posts
- 58,170
- Location
- Preston Lancs.
Locked at TDC one bright link should be on the tooth next to the mark on the crank sprocket and one should be on the tooth with the 6 mark on the pump sprocket. Looking directly at the pump sprocket this should place the key way at the top maybe a few minutes past the hour. The key way on the pump should be vertical, next cylinder to fire number one. Make sure the bright links are correct, first bright link is number one next bright link one should twelfth raised link from that. Just in case the chain has been assembled incorrectly, doubtful but it does happen. What you have at the moment only being able to get .71 mm lift on cam is no good. What are you going to do when chains stretch? There is no further movement possible to advance static.Something has been cocked up somewhere you need to find and correct it.
