Thread: TD5 surging under acceleration.

could be an over boost problem.

Plug the nano in and go to read fueling in the td5 engine section.

The ecu will go into overboost if the MAP sensor reads above 240 kpa (give or take depending on outsie air pressure)

Have you considered the Turbo Modulator valve?

Small black box just behind turbo inlet pipe.Check state of hoses for splits etc.
Not an expensive part to replace if required.


Trev.

Originally Posted by Benny_IIA

could be an over boost problem.

Plug the nano in and go to read fueling in the td5 engine section.

The ecu will go into overboost if the MAP sensor reads above 240 kpa (give or take depending on outsie air pressure)

Will try that when I get home. When you say 240kpa is that at idle? I thought it was much higher under load.

Originally Posted by trev

Have you considered the Turbo Modulator valve?

Small black box just behind turbo inlet pipe.Check state of hoses for splits etc.
Not an expensive part to replace if required.


Trev.

Defenders don't run a modulator valve, disco only.

I would check the pipe to the wastegate actuator for leaks, or a sticking wastegate.

JC

Originally Posted by CraigE

Will try that when I get home. When you say 240kpa is that at idle? I thought it was much higher under load.

Craig, 240 kpa (this is the nanocom readout which includes 100kpa ambient) is under load with WOT and if overboosting should go into limp mode with loss of power and is reset with ignition off (at least on my td5 defender anyway).

If the Maf sensor exceeds its maximum flowrate it will cut fuelling giving the symptoms you describe but you need to have a few mods in place for that to happen and once again only with WOT under load.

I would be looking at JC's tips on the wastegate etc.
Another thing to look at if no luck with the turbo is the TPS (throttle position sensor).

Cheers,
Paul.

My $$$ is on oil in the ECU/red plug.
It improved when cleaned but have you stoped the small flow of oil from the injector harness?
I'd have a look at the red plug again even if only for peace of mind.

Originally Posted by alien d2

My $$$ is on oil in the ECU/red plug.
It improved when cleaned but have you stoped the small flow of oil from the injector harness?
I'd have a look at the red plug again even if only for peace of mind.

I replaced the harness about 2 months ago, 5000kms maybe and last I checked it was OK with none getting to the harness plug near the head. I think all I have is residual oil in the main harness working its way through. I will check again when I fly home.
The issue it has is I have had little bits of oil come through and cleaned regularly since replacing. While in Newman I had not done many big drives so there was bugger all evident. With the 2 trips to Perth recently to move down, it has some high kms and there as been a little oil pooling. I already have the seal out so it can drain. It did not seem to impair performance.
The problem now is to try and diagnose if it is overboosting, stuck modulator valve, MAF, TPS, fuel pump or even Crank Angle Sensor.
Thanks for the input.

Originally Posted by harro

Craig, 240 kpa (this is the nanocom readout which includes 100kpa ambient) is under load with WOT and if overboosting should go into limp mode with loss of power and is reset with ignition off (at least on my td5 defender anyway).

If the Maf sensor exceeds its maximum flowrate it will cut fuelling giving the symptoms you describe but you need to have a few mods in place for that to happen and once again only with WOT under load.

I would be looking at JC's tips on the wastegate etc.
Another thing to look at if no luck with the turbo is the TPS (throttle position sensor).

Cheers,
Paul.

I will have to reload the Nanocom software on my laptop when I get home. Got a new one a few months ago and have not loaded it on yet. Was on my old one I gave my boy but that has crashed so can not use that. Hopefully I can set it up this weekend and then get some data.
Seems to be a bit like fuel starvation and why I immediately replaced the filter. If it is a pump that is going to hurt. Would be ideal if there was a easy way to confirm what it is.
Will start with the modulator valve and work my way through.
Cheers
Craig