A Challenge To Mechanics

Bromsgrove Defender · Mar 16, 2012

I know you said you put a new fuel pump on but it is working properly isn't it???

It's not totally unheard of for "new" parts to be faulty

ScroobiusPip · Mar 17, 2012

Finally got some help from a RR dealer (Stratsone in Newport Pagnell) and they've ordered the part, £76, if that's not the problem I'll fit it Sat and if that doesn't sort it out, main dealer for diagnostics on Tuesday!!

wammers · Mar 17, 2012

Datatek said:
Pretty sure that the Manifold Absolute Pressure does show up on diagnostics, at least on Faultmate using live data

Yes think you are correct Keith. Shows up on Nanocom aswell. It's the MAF that can't be read.

ScroobiusPip · Mar 17, 2012

wammers said:
Yes think you are correct Keith. Shows up on Nanocom aswell. It's the MAF that can't be read.

I'll stand corrected on that then by people who know a lot more than me

, new MAP is fitted, has made a difference, more power but still not right, I'm going to isolate the EGR with a penny tomorrow, too much rugby to watch today

, and see if that makes a difference.
Fault seems to have changed now, if while I'm driving, say at about 50mph, and I take my foot off the accelerator, the engine management light comes on and there is no response on the accelerator, begining to wonder if the throttle sensor is faulty as well, or possible ECU.
Would a faulty MAF cause the original problems?

Datatek · Mar 17, 2012

ScroobiusPip said:
I'll stand corrected on that then by people who know a lot more than me , new MAP is fitted, has made a difference, more power but still not right, I'm going to isolate the EGR with a penny tomorrow, too much rugby to watch today , and see if that makes a difference.
Fault seems to have changed now, if while I'm driving, say at about 50mph, and I take my foot off the accelerator, the engine management light comes on and there is no response on the accelerator, begining to wonder if the throttle sensor is faulty as well, or possible ECU.
Would a faulty MAF cause the original problems?

Crank sensor playing up, EDC thinks the engine has stopped when it loses the needle lift sensor signal

ScroobiusPip · Mar 22, 2012

Update
Just picked it up from the land rover main dealer, and they can't find out what's wrong with it!!! The only fault code was that the injector settings were off, which they corrected, but the revs still drop suddenly when idling, and it sometimes stalls when you put it in gear. There are now no fault codes coming up.
The power has improved, but it still doesn't feel right, so any suggestions? I think the new injector, fitted before I bought it is fine, as I think it was fitted to try and cure the problem, and I have loads of paperwork for the vehicle from the previous owner in chronological order, and there is no mention of the diesel injector pump in any of them. The last sheet is one of them trying to solve the problem.
My plan now is to try blanking off the EGR again, see if that makes a difference, then the MAF sensor, then get a quote for a new ECU.
I don't want to give up on this because it is so well sorted in every other aspect.
Thanks for all your input so far, keep them coming

The Mad Hat Man · Mar 22, 2012

You obviously have no fault. it must be a figment of your imagination

Saint.V8 · Mar 22, 2012

There is a system that monitors engine load and increases fuelling to prevent stalling when, say, you put it in gear, or turn the heated windows on, or all the lights, as this additional load slows the engine, so a system was installed to monitor this and increase the fuelling....

Not sure how it works, whether it is a software thing that tells the FIP to inject more fuel or if there is a servo motor that retimes the FIP to increase fuelling I am not sure....

Might be something to research and investigate....or I could be totally wrong, but distant church bells are ringing on this....

wammers · Mar 22, 2012

Saint.V8 said:
There is a system that monitors engine load and increases fuelling to prevent stalling when, say, you put it in gear, or turn the heated windows on, or all the lights, as this additional load slows the engine, so a system was installed to monitor this and increase the fuelling....

Not sure how it works, whether it is a software thing that tells the FIP to inject more fuel or if there is a servo motor that retimes the FIP to increase fuelling I am not sure....

Might be something to research and investigate....or I could be totally wrong, but distant church bells are ringing on this....

When at tickover, if crank sensor detects a fall in RPM due to load ECM increases fuelling to compensate via fuel quantity servo in injector pump. Likewise if load is removed and a rise in RPM is detected fuel is reduced to maintain 750 RPM +- 50. It is either a dicky crank sensor not picking up the change in RPM or the fuel quantity solenoid not reacting quickly enough. Can't see it being ECM. But sometimes strange things happen. This may come from fuel modulation being out. Injector pump needs re timing.

ScroobiusPip · Mar 22, 2012

wammers said:
When at tickover, if crank sensor detects a fall in RPM due to load ECM increases fuelling to compensate via fuel quantity servo in injector pump. Likewise if load is removed and a rise in RPM is detected fuel is reduced to maintain 750 RPM +- 50. It is either a dicky crank sensor not picking up the change in RPM or the fuel quantity solenoid not reacting quickly enough. Can't see it being ECM. But sometimes strange things happen. This may come from fuel modulation being out. Injector pump needs re timing.

Cheers Wammers, I did ask about the crank sensor when I picked it up and was told if it was faulty it would of shown up, but who knows, what seems weird to me is that it will be ticking over sweet as a nut, then the revs will suddenly drop, like somethings suddenly put a load on the engine, but nothings been touched.

wammers · Mar 22, 2012

ScroobiusPip said:
Cheers Wammers, I did ask about the crank sensor when I picked it up and was told if it was faulty it would of shown up, but who knows, what seems weird to me is that it will be ticking over sweet as a nut, then the revs will suddenly drop, like somethings suddenly put a load on the engine, but nothings been touched.

It does load and unload on tickover. The alternator contrary to popular belief does not charge at a constant rate or it would boil the battery. It reduces it's rate as the battery gets full then as the voltage in the battery drops ups the rate to compensate. But i don't think that is the entire problem. I have a theory that if the chains have stretched and the pump timing is retarded, that causes this. When the pump is static timed there is a lift applied to the pump piston as it engages on the pump cam. This means that at TDC the piston has already began to move suppling fuel. If the chain stretch has caused the piston NOT to be engaged at TDC no fuel is being delivered, so the fuel solenoid has to be set by the ECM to a false position to maintain tick over, this against spring pressure. I think because this position is against spring pressure, and no fuel is being delivered because of the pump being retarded the solenoid just cannot react fast enough to catch the dip in revs as the spring pressure pulls the solenoid to a position it would normally be at IF the pump was timed correctly. No fuel engine stops. But they are only my thoughts. Mine does this now and again and i know my modulation is out. So when the better weather arrives i will re time the pump and test out my theory. This could also have something to do with the engine lamp flicking on now and again as you lift off the throttle.

Saint.V8 · Mar 22, 2012

wammers said:
It does load and unload on tickover. The alternator contrary to popular belief does not charge at a constant rate or it would boil the battery. It reduces it's rate as the battery gets full then as the voltage in the battery drops ups the rate to compensate. But i don't think that is the entire problem. I have a theory that if the chains have stretched and the pump timing is retarded, that causes this. When the pump is static timed there is a lift applied to the pump piston as it engages on the pump cam. This means that at TDC the piston has already began to move suppling fuel. If the chain stretch has caused the piston NOT to be engaged at TDC no fuel is being delivered, so the fuel solenoid has to be set by the ECM to a false position to maintain tick over, this against spring pressure. I think because this position is against spring pressure, and no fuel is being delivered because of the pump being retarded the solenoid just cannot react fast enough to catch the dip in revs as the spring pressure pulls the solenoid to a position it would normally be at IF the pump was timed correctly. No fuel engine stops. But they are only my thoughts. Mine does this now and again and i know my modulation is out. So when the better weather arrives i will re time the pump and test out my theory. This could also have something to do with the engine lamp flicking on now and again as you lift off the throttle.

I'm sticking to Gas Turbines....Aslong as there is air infront of it going in - Fuel in the middle of it burning - and nothing blocks the hot exhaust going out the back, it will run till you kill the fuel....

I am starting to regret getting a Diesel, this FIP system sounds fecking complicated!!

Datatek · Mar 22, 2012

Mine starts and runs perfectly hot or cold but with the aircon on there is a momentary drop in revs when the air con compressor engages. Alternator load will vary with things like the EAS compressor or brake pump cutting in.

ScroobiusPip · Mar 23, 2012

wammers said:
It does load and unload on tickover. The alternator contrary to popular belief does not charge at a constant rate or it would boil the battery. It reduces it's rate as the battery gets full then as the voltage in the battery drops ups the rate to compensate. But i don't think that is the entire problem. I have a theory that if the chains have stretched and the pump timing is retarded, that causes this. When the pump is static timed there is a lift applied to the pump piston as it engages on the pump cam. This means that at TDC the piston has already began to move suppling fuel. If the chain stretch has caused the piston NOT to be engaged at TDC no fuel is being delivered, so the fuel solenoid has to be set by the ECM to a false position to maintain tick over, this against spring pressure. I think because this position is against spring pressure, and no fuel is being delivered because of the pump being retarded the solenoid just cannot react fast enough to catch the dip in revs as the spring pressure pulls the solenoid to a position it would normally be at IF the pump was timed correctly. No fuel engine stops. But they are only my thoughts. Mine does this now and again and i know my modulation is out. So when the better weather arrives i will re time the pump and test out my theory. This could also have something to do with the engine lamp flicking on now and again as you lift off the throttle.

Is this easy to do, do you need any specialist equipment to do it, as I think you are right and this is the problem I have with mine.

wammers · Mar 23, 2012

ScroobiusPip said:
Is this easy to do, do you need any specialist equipment to do it, as I think you are right and this is the problem I have with mine.

Yes you need special tools to time pump.

ScroobiusPip · Mar 24, 2012

wammers said:
Yes you need special tools to time pump.

This might be a dopey question, I'm good at those!!, but why would you not fit new timing chains, is it just too big a job?

wammers · Mar 24, 2012

ScroobiusPip said:
This might be a dopey question, I'm good at those!!, but why would you not fit new timing chains, is it just too big a job?

You can do, if you want to take the cylinder head and sump off to remove front timing case.

ScroobiusPip · Mar 24, 2012

wammers said:
You can do, if you want to take the cylinder head and sump off to remove front timing case.

OK, I looked at a diagram and it looked like an access panel on the front once you got the rad out of the way

wammers · Mar 24, 2012

ScroobiusPip said:
OK, I looked at a diagram and it looked like an access panel on the front once you got the rad out of the way

Yeah it's called the front cover and it has to come off the replace the chains.

Freelaner · Mar 24, 2012

wammers said:
yeah it's called the front cover and it has to come off the replace the chains.

:d:d:d

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