Hesitation / misfire TD5

Looking for some help please having followed the forum for a while.

Sierrafery (or anyone else !)- if you are out there I have read your posts on issues relating to wastegates and mapping and would appreciate any help as you seem to have been around this issue before.

TD5 2001 defender 10p engine. It hesitates / misfires (intermittently) only ever under light acceleration, Cruise at 50mph it will sometimes hesitate, 2nd gear low range it will kangaroo sometimes. Drive it hard and there is no problem. I have now found the problem is related to off boost (I think), once the turbo comes in there is no problem.

When it started it was only noticeable when engine temp cold and was different but I now assume it was the same issue which was exaggerated by the remap and then started happening when engine was warm too .

If I back off the wastgate actuator all the way, the problem becomes easy to reproduce and is more obvious and is present in more of the first part of the accelerator pedal travel (once the turbo gets going the problem disappaears), wind it back to normal position (13 threads) its less obvious and only for less of the pedal travel, wind it on another thread, it goes away more and for less of the pedal travel, another thread (11 showing) same result and less obvious.

I think that once the turbo is coming into play earlier (which I am doing by adjusting the actuator) the problem disappears. I cant get rid of it completely by adjusting the actuator but I can influence it and make it more or less obvious and more persistent.

What I need help with is interpreting what that could mean

Remap guys suggest MAP sensor or FPR but FPR now done.

The engine loom is oily. I dont have oil coming from injector harness anymore. However, there are some random fault codes that cannot be cleared and garage has suggested engine loom could be at fault

So, I dont know if the actuator adjustment means its a mechanical issue or if the actuator adjustment is masking something else or if its buggered loom sending wrong signals or if it could be MAP sensor (or something else). I am also doubting (but only gut instinct) that if the fault codes wont clear because of oily loom then I assume live data messages could be mixed up too

Any words of wisdom would be gratefully received

Hi, if you have oil in the plug which connects to the injector loom at the head you have to replace the injector loom first , simply playing with the wastegate without any live data log is completely irrelevant . This kind of issue needs proper diagnostics otherwise it's a guessing game. First of all what are those current fault codes ?

sierrafery said:

Hi, if you have oil in the plug which connects to the injector loom at the head you have to replace the injector loom first , simply playing with the wastegate without any live data log is completely irrelevant . This kind of issue needs proper diagnostics otherwise it's a guessing game. First of all what are those current fault codes ?

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Ok, thanks. Just found that the FPR isnt sealed properly so it could still be that. Will sort that out and report back

The FPR or any other element of the fuel delivery system would not throw fault codes.

sierrafery said:

The FPR or any other element of the fuel delivery system would not throw fault codes.

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Hi Sierrafery,

FPR now sealed. Engine loom has been changed (was dripping with oil) but problem still present.

I have now managed to get its fault codes read. Other than the stuff that does not apply because its not fitted (air con etc), I have two (or poss 3) fault codes that wont clear down.

The Autel MaxiSys reader said these codes were present and would not clear:

• Gearbox / ABS open load
• 160, CAN error fault

The snap on reader

• displayed an open load fuel pump fault which would not clear but the other reader did not pick this up.

I have read another of your post responses re fuel pump open load and have already swapped the relay for another with no luck.

My fuel pump"sounds" healthy and once the turbo is spooling up, the car accelerates very cleanly with no hesitation. The stutter / misfire only happens under light load before the turbo boosts.

One thing that I have now realised may be significant is the hesitation is only when off boost when moving. When stationery, I cannot make it stutter at any point in rev range. I have read somewhere else that the turbo only produces boost under load......does that sound correct in your experience and if so how much could that narrow down the search ?

Thanks for any help

Is it not a boost leak? Its worth checking all hoses and your intercooler. But if your ecu loom is shot then thats job #1 to fix and go from there

Just started looking for leaks etc in pipework. Ended up removing actuator from wastegate and have found the wastegate has no resistence to it. It flaps around. I think (hope) this is the cause as I understand the wastegate should return to position itself to give resistence against actuator.
It also makes sense how I can adjust actuator rod and this effects how much travel I get in the pedal before the turbo spools up and it drives past the hesitation point.

Would a broken wastegate spring give hesitation / surging just as turbo starts to spool up ?

Dexterdog said:

Just started looking for leaks etc in pipework. Ended up removing actuator from wastegate and have found the wastegate has no resistence to it. It flaps around. I think (hope) this is the cause as I understand the wastegate should return to position itself to give resistence against actuator.
It also makes sense how I can adjust actuator rod and this effects how much travel I get in the pedal before the turbo spools up and it drives past the hesitation point.

Would a broken wastegate spring give hesitation / surging just as turbo starts to spool up ?

Click to expand...

I had a situation where at higher rpm under load (4th, 5th) it started missing badly, drop revs a little bit and all fine. Like going through the sound barrier in an X1.
My nanocom said it was stuck wastegate, cleaned it up a bit and cleared codes and so far not reoccured