TD5 Misfiring after 10 or 12 miles

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Nigel-S

Nigel-S

soft and furry
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6,070
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Englishman up a big steep hill in South Wales
As per title, no problem at all during the first 10 or 12 miles then starts to misfire quite badly. Engine doesn't stop, just misfires. No oil in the ECU plug and the harness was recently changed, the only thing I've done since this started was to fuel up. Possibly water in fuel? Injector seals? Any thoughts chaps?
 
Nigel-S said:
As per title, no problem at all during the first 10 or 12 miles then starts to misfire quite badly. Engine doesn't stop, just misfires. No oil in the ECU plug and the harness was recently changed, the only thing I've done since this started was to fuel up. Possibly water in fuel? Injector seals? Any thoughts chaps?
Click to expand...
I have a Defender TD5 but I am still learning about all of its problems, but I recently changed the injector seals and it made a big improvement in my engine, and they don't cost much, I also bought a kit and changed the fuel pressure regulator, which seemed to help. If you do do the seals take care to keep everything spotlessly clean and run the bleed process a few times after you finish to try and flush it out.
Is your in tank diesel pump whining when you turn on the ignition ?
 
raywin said:
I have a Defender TD5 but I am still learning about all of its problems, but I recently changed the injector seals and it made a big improvement in my engine, and they don't cost much, I also bought a kit and changed the fuel pressure regulator, which seemed to help. If you do do the seals take care to keep everything spotlessly clean and run the bleed process a few times after you finish to try and flush it out.
Is your in tank diesel pump whining when you turn on the ignition ?
Click to expand...

I was thinking that it it would be wise to change the injector seals, did it on my last TD5 and pretty straightforward (just ordered up the seals). Not thought of the fuel pressure regulator? but another thing to eliminate. Fuel pump seems fine but another thing to check, also the fuel filter is due for a change. Looks like it'll be a process of elimination. Thanks for your input ;):)
 
Nigel-S said:
I was thinking that it it would be wise to change the injector seals, did it on my last TD5 and pretty straightforward (just ordered up the seals). Not thought of the fuel pressure regulator? but another thing to eliminate. Fuel pump seems fine but another thing to check, also the fuel filter is due for a change. Looks like it'll be a process of elimination. Thanks for your input ;):)
Click to expand...
The filter is a good idea, most people on here swear by the OEM filters, they are probably a good idea.
I changed the pressure regulator when mine was hard to start and the pump started whining, I also did the bleed valve on the filter housing, starts fine now and runs better, but I don't know which one cured it, maybe a combination of all of them.
 
Would be good to plug in a tester before you do jobs on it, then if no faults logged you know it's fuel supply related, the injector copper washers should make it hard to start from cold rather than make it rough when warm and the o-rings would let diesel in oil
 
sierrafery said:
Would be good to plug in a tester before you do jobs on it, then if no faults logged you know it's fuel supply related, the injector copper washers should make it hard to start from cold rather than make it rough when warm and the o-rings would let diesel in oil
Click to expand...
Yes I agree 100% if you can get a tester plugged in it can save a lot of frustration and guess work,
My engine had bad starting but the pump also started to whine when it had run a while, I suspect the copper injector seals were allowing the combustion gas to blow back into the diesel feed around the injectors. When it was hot it never seemed to run smooth. I changed the seals and the engine suddenly sounded much smoother especially when pulling up hill. When I changed the fuel pressure regulator it seemed to go better at motorway speeds.
But I joined the Nanocom group buy, it is a much better way to diagnose problems.
 
I've fitted a new fuel filter and no difference at all, the fuel pump is running as it should. Still starts instantly on the turn of the key but if I bring the revs up to 2000rpm whilst stationary, I can just detect a bit of rough running. Can't find anyone with a tester locally and I'm moving house so couldn't come at a worse time, the move is 120 miles so no chance of driving it that far (might make the first 10 miles :rolleyes:).
 
Nigel-S said:
I've fitted a new fuel filter and no difference at all, the fuel pump is running as it should. Still starts instantly on the turn of the key but if I bring the revs up to 2000rpm whilst stationary, I can just detect a bit of rough running. Can't find anyone with a tester locally and I'm moving house so couldn't come at a worse time, the move is 120 miles so no chance of driving it that far (might make the first 10 miles :rolleyes:).
Click to expand...
its worth unscrewing the sensor or plug on bottom of filter, place a container underneath and switch ignition on it should flow out fast and smooth, also check coolant system is full by removing bleed screw,temp sensor doesnt like air passing it
 
Just took the car down the road after fitting the fuel filter, when I arrived back home I checked the fuel filter for leaks. No leaks but it was pretty hot, no so hot I couldn't touch it but nonetheless it was hot, I only covered 2 miles. Not sure if this has any bearing on the problem since it's not something I've come across before o_O

biggeeeee said:
How did you test this.
The fuel pump was the cause of my rough running and after a few months the vehicle refused to start.
Click to expand...

I could only test during the priming process after replacing the filter, appeared to be running as it should run (no guarantee it's not faulty I know).

jamesmartin said:
its worth unscrewing the sensor or plug on bottom of filter, place a container underneath and switch ignition on it should flow out fast and smooth, also check coolant system is full by removing bleed screw,temp sensor doesnt like air passing it
Click to expand...

I'll give that a try ;)
 
Update:

Today I fitted new seals and 'O' rings to the injectors, gave the injectors a good clean though they were pretty clean anyway. Started it up once the job was done and it ran fine for 5 minutes or so, then reverted to the misfiring again :(.

I have a new fuel pump that I intend to fit tomorrow, though I doubt this will solve the problem.

Not been able to find anyone with a Hawkeye or Nanocom and can't stretch to buying one at the present time (moving house), so it's all trial and error at present.
 
can be the crank sensor but that should be confirmed with tester otherwise changing parts based on presumptions or luck might be more expensive than a tester itself
 
Didnt this exact issue come up around Christmas last year?
Solution was injector loom, I know you said its been changed but new could have been faulty.
Any other forumites near to you? could anyone loan you a good one?!
At the time I was pondering temperature related things, like water temp sensor etc.
Mark
 
markomate2 said:
Didnt this exact issue come up around Christmas last year?
Click to expand...

I had a similar problem a few years back with another TD5, but in that case it was the fuel pump that was knackered. I've got a couple of spare looms so might be worth a swap just to eliminate a potential culprit. I've also got a spare cam sensor (Sierrafery's suggestion), so another elimination. As for getting hold of someone with a Nanocom or Hawkeye, there is someone local but they want an arm and a leg to hook it up (not a member on LZ).
 
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