Defender 2.4 Puma: last ditch effort to solve intermtitent power loss

[MY LANDY]

Feels like all I do is pepper this forum with Puma problems, so let me open this thread by thanking all those who have attempted to help a bloke who pushed a keyboard and not spanners for a living.

This post follows on from these two (in order):

Strange 'gurgling' sound before turbo spools up. (http://www.aulro.com/afvb/90-110-130-defender-county/242392-anyone-know-sound-2-4-puma-110-sickly-gurgle.html)
Blocked Catalytic Converter. (http://www.aulro.com/afvb/90-110-130-defender-county/241839-blocked-cat-converter-defender-puma-2-4-110-a.html)

It's been two months, hours spend checking fuel filter, hoses and exhaust, two trips to Graeme Cooper, diagnostics testing, dyno testing... and nothing.

Car is still intermittently losing power. One day I'll jump in and burn up the local hill in fourth, the next I'm forced to gear down from third to second. When it does this it feels like the car is towing a parachute.


Got fault for pump learn and were unable to conduct learn.
Had a BAS remap with EGR shut. Replaced with standard profile and blanked EGR.
Able to run pump learn and clear. Fault code hasn't returned.
Fuel rail pressure reports as normal.
No other fault codes.
Performance on dyno was normal up top, but a bit soft down low; dropped exhaust, knocked middle (looks like ultra-fine fly screen and was pretty sooty but not blocked) out of the catalytic converter and got triple the power down low.
Problem returned.
With window down noticed the gurgling sound, almost like a turbo wastegate (only Puma's don't have 'em).


So I'm down to replacing the VCV and running pump learn again. But it doesn't explain that bloody sound. Any ideas?

Should that fail to fix the issue, next (more extreme and costly) is the turbo. Anyone had theirs stick (block up with carbon)? What sounds and/or symptoms?

As always, 'preciate your time and advice.

Jethro

[TimNZ]

Hmmm, off the top of my head things to check, (sorry don't know the full history of things you have checked),

Stuck turbo variable vane actuator/stripped gears in the actuator
Bad wiring to the turbo vane actuator (there was a recall for this)
Bad CHT sensor
Bad air flow meter
Bad throttle pedal, (unlikely, but...)

Strange you were unable to do the fuel pump learn. I assume you were trying to do the learn with the engine hot? (above 74deg from memory). If it's cold, depending on the diagnostic system, it will go through the motions, but won't "learn" anything. My 2nd 2.4 came from the dealer like this, after talking with Pete from BAS and redoing the learn process with the engine hot it ran much better.

From what I know the EGR system is very well monitored, so any faults with EGR valve positioning will throw a fault code. However there is no feed back from the turbo actuator, the ecu simply assumes it's moved. (Prepared to stand corrected on that, but that's what I recall from when I owned a 2.4).

Good luck,

[XSiV]

Feels like all I do is pepper this forum with Puma problems, so let me open this thread by thanking all those who have attempted to help a bloke who pushed a keyboard and not spanners for a living.



This post follows on from these two (in order):



Strange 'gurgling' sound before turbo spools up. (http://www.aulro.com/afvb/90-110-130-defender-county/242392-anyone-know-sound-2-4-puma-110-sickly-gurgle.html)

Blocked Catalytic Converter. (http://www.aulro.com/afvb/90-110-130-defender-county/241839-blocked-cat-converter-defender-puma-2-4-110-a.html)



It's been two months, hours spend checking fuel filter, hoses and exhaust, two trips to Graeme Cooper, diagnostics testing, dyno testing... and nothing.



Car is still intermittently losing power. One day I'll jump in and burn up the local hill in fourth, the next I'm forced to gear down from third to second. When it does this it feels like the car is towing a parachute.





Got fault for pump learn and were unable to conduct learn.

Had a BAS remap with EGR shut. Replaced with standard profile and blanked EGR.

Able to run pump learn and clear. Fault code hasn't returned.

Fuel rail pressure reports as normal.

No other fault codes.

Performance on dyno was normal up top, but a bit soft down low; dropped exhaust, knocked middle (looks like ultra-fine fly screen and was pretty sooty but not blocked) out of the catalytic converter and got triple the power down low.

Problem returned.

With window down noticed the gurgling sound, almost like a turbo wastegate (only Puma's don't have 'em).





So I'm down to replacing the VCV and running pump learn again. But it doesn't explain that bloody sound. Any ideas?



Should that fail to fix the issue, next (more extreme and costly) is the turbo. Anyone had theirs stick (block up with carbon)? What sounds and/or symptoms?



As always, 'preciate your time and advice.



Jethro



I don't have a puma but I did experience intermittent power loss in my td5. Turned out to be a faulty MAF sensor. Replaced it and all running as it should. Another thing you could check is your inlet pipes from the turbo. I had mine delaminate and it would cause massive power loss due to the inside of the pipe getting sucked closed. That might explain a gurgling sound if it was kind of vibrating in the airflow. Silicon pipes fixed that issue.

[MY LANDY]

Had the fellas at Graeme Cooper do the pump learn while vehicle was hot and on standard map.

Got silicone hoses already in – anyone ever heard of them delaminating? I did pull them out, visually inspect and blow through to check for blockages, but obviously not at temp and pressure they would run when in vehicle. Thanks fellas.

[Chops]

I had an issue with mine, but not just a power down,, it went right off for a second or two. Ended up being the ECU which when replaced, fixed all issues. (Although LR couldn't do the pilot program, I ended up getting that done privately on a dyno).

[XSiV]

Had the fellas at Graeme Cooper do the pump learn while vehicle was hot and on standard map.

Got silicone hoses already in ? anyone ever heard of them delaminating? I did pull them out, visually inspect and blow through to check for blockages, but obviously not at temp and pressure they would run when in vehicle. Thanks fellas.



I've not heard of a silicon hose delaminating as yet. When it happens it's a sudden dramatic loss of power which resumes almost as soon as the engine slows down. Your problem sounds more like the problem I had with my MAF. I'd get that checked.