2.5 dse auto Power loss..?

Datatek · Dec 8, 2018

Baiman said:
Ok, thanks for the advice thus far... so I replaced the in tank pump and there was a slight improvement in up hill grunt, but not a lot and the original problem still persists. Off the mark sometimes I get boost, most of the times its flat as a pancake. Going up hills is fine up to a point and then the boost just drops off and its back to 10j performance. Take foot of pedal and reapply and it usually comes back on boost for a short while (10 - 20 seconds) before dropping off again. So started thinking perhaps it was gulping air into the fuel sysytem somewhere... checked the fuel filter seal, it's fine and working as it should. No obvious bubbles in clear lines, leaks or wet patches when left running on the drive for an hour.

Last night got right pi$$3d off with it and pulled over and jammed the binoculars box between the pedals to hold it at 2500rpm while I checked the pipes over yet again... First off I noticed that the leakoff pipes are 'thumping' particularly hard when held between finger and thumb, most noticeable across cylinders 3 & 4. I pulled the leak off pipes and they are dry, not a drop of fuel in them at either 2500rpm or on tickover? She has been returning pathetic MPG since the problem occured, averaging 14mpg over the last few weeks, so I reccon that there's no fuel going back to the tank, but like I said, there are no discernable leaks and the oil level isn't rising noticeably over the passed 2 weeks despite daily checks for fear of the rings needing replaced... any ideas would be great, because its almost like a fuel sucking vampire is sucking the life and fuel right outta her before flying off without a trace :? I would really appreciate some further guidance, because she is costing me about £0.70 per mile at the moment and she's my daily works truck. Thanks guys.

Sounds like it could be a couple of knackered injectors. Try slacking of the fuel pipes at each injector in turn to check there is fuel and bleed any air. Wear gloves and goggles, high pressure diesel is dangerous.

wammers · Dec 8, 2018

Baiman said:
Boost pipes are presurising when pedal down...

It rings of MAP sensor not sending proper signals to ECU it does not matter how much manifold pressure it has if the ECU is not providing boost fuel you will not get power. The fuel feed is pressurised it cannot suck in air, fuel can only leak out.
You need good diag on it, you would see the problem immediately if it is indeed as i say above.

tanis8472 · Dec 8, 2018

Have you checked the wiring from the sensor to ecu for damage/water etc

wammers · Dec 8, 2018

Map sensor. Pin 1 Blue/yellow is signal to pin 54 ECU. Pin 2 Brown/green to pin 13 ECU. Pin 3 White to pin 51 ECU. If the MAP sensor is working correctly. With engine running and revved you should get a variable voltage to pin 54 ECU as the revs rise and fall.

Mark Piercy · Dec 8, 2018

Maybe a leakoff test on the injectors to varify you dont have a jammed open injector?

wammers · Dec 8, 2018

Mark Piercy said:
Maybe a leakoff test on the injectors to varify you dont have a jammed open injector?

If he had a jammed injector he would have smoke and crap all over the place. Problem is MAP sensor.

Mark Piercy · Dec 8, 2018

wammers said:
If he had a jammed injector he would have smoke and crap all over the place. Problem is MAP sensor.

Very true.. it be smokin' like goodn'..... The diag would reveal the map sensor value change when revving the engine,that is if its functioning correctly.
You have checked the pipe and the exit from the manifold isnt blocked?
Has someone asked already

wammers · Dec 8, 2018

Mark Piercy said:
Very true.. it be smokin' like goodn'..... The diag would reveal the map sensor value change when revving the engine,that is if its functioning correctly.
You have checked the pipe and the exit from the manifold isnt blocked?
Has someone asked already

Post # 3.

Datatek · Dec 8, 2018

Mark Piercy said:
Very true.. it be smokin' like goodn'..... The diag would reveal the map sensor value change when revving the engine,that is if its functioning correctly.
You have checked the pipe and the exit from the manifold isnt blocked?
Has someone asked already

No smoke if the injector is not opening.

wammers · Dec 8, 2018

Datatek said:
No smoke if the injector is not opening.

But very uneven running he does not report that.

Grrrrrr · Dec 10, 2018

Why's there no fuel from the leak off pipe? Surely there's way more fuel going through than needed by the injectors? Would no MAP reduce fuel flow that much?

Grrrrrr · Dec 10, 2018

Baiman said:
Boost pipes are presurising when pedal down...

Is there a Nanocom or similar near you on the LZIR map?

Devon. Cannot remember who is down that way. @PastyMuncher83 might know if there's a member down that way with a Nanocom.

wammers · Dec 10, 2018

Grrrrrr said:
Why's there no fuel from the leak off pipe? Surely there's way more fuel going through than needed by the injectors? Would no MAP reduce fuel flow that much?

You have lost me where does he say that?

Datatek · Dec 10, 2018

wammers said:
You have lost me where does he say that?

Early on he said that removing the leak off showed no fuel leaking off from the injector.
I suggested he cracked off the fuel pipe nuts at the injectors one at a time to check for fuel and remove any air.

wammers · Dec 10, 2018

Datatek said:
Early on he said that removing the leak off showed no fuel leaking off from the injector.
I suggested he cracked off the fuel pipe nuts at the injectors one at a time to check for fuel and remove any air.

Yep read through and seen that now. If the injectors are in good nick there should be leak off. They are designed with loosish tolerance to avoid goring that is why you need leak off pipes. Maybe they need servicing. But that said it is unlikely that is causing his loss of power. I still favour the MAP sensor being dicky.

stemac33 · Dec 10, 2018

Have you tried the fuel flow test In tech archive by wammers.
Checking diesel fuel pump flow rate.
Just a thought as when I swapped engines in mine I couldn't get it to bleed. Found when I change the intank pump I had got the lines crossed so it was pumping fuel to the leak off side instead of the filter but the car started and ran ok.

brianp38dse · Dec 10, 2018

I can confirm that they drive very sluggish with out a map sensor, its not to as bad low revs low speeds but try and give it some throttle and not a lot will happen and lifting of then back on a little it seams to help and hills forget it just slows down,

so worth a look at as wammers said .

Grrrrrr · Dec 10, 2018

wammers said:
They are designed with loosish tolerance to avoid goring that is why you need leak off pipes.

What's goring, chap?

wammers · Dec 10, 2018

Grrrrrr said:
What's goring, chap?

Two pieces of metal rubbing together and marking the surface finish or causing the parts to seize.. Moving parts in injectors have fairly generous clearances to prevent goring and/or particles in the fuel from seizing them. That is why you have leak off.

Grrrrrr · Dec 10, 2018

wammers said:
Two pieces of metal rubbing together and marking the surface finish or causing the parts to seize.. Moving parts in injectors have fairly generous clearances to prevent goring and/or particles in the fuel from seizing them. That is why you have leak off.

Thought it might be. Same as scoring then. Cheers.

2.5 dse auto Power loss..?

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