Thread: Td5 low power - fuel pump vs MAF

Hi Muppet

I don't have any great solutions but do have a couple of thoughts.

You're right regarding the MAF but all is not lost. It would be good to see how it goes when driving to get a conclusive figure, typical cruising figures are mid 100's to mid 200's and max readings in the 500's. Give it a clean with Contact or MAF cleaner (when stone cold) and also check the wiring and connectors back to the ECU.

Also have a look at the fuel filter in the rear wheel arch. This is where most crud from the tank will be trapped. From memory the in tank pump only has a coarse screen. If its been on a while it could be worth changing.

Cheers

Steve

Hi Steve.

I gave the the MAF a good clean (when stone cold) with a MAF cleaner when I did the FPR and it didn't do anything that I noticed, although I did put the wrong FPR gasket on the first time so it may have masked any improvement.
It still drives okay, hills are not so pleasant. It WILL rev past 3000 but it's difficult to get it to do so and then only a little bit more.

From the thread linked previously, there seems to be more than one filter in the pump so I'll check that out. The fuel filter is <5k kms old.

Have you verified that the waste-gate moves freely?

Bypassing the boost modulator limits the boost to 1 bar as determined by the waste-gate actuator spring whereas with an operating modulator boost can be up to around 1.4 bar, which makes for quite a bit more power.

I have tested the waste gate arm, it takes 'some' force but it does move and it didn't appear to stick.

Checked my fuel air bleed valve filter after a tip that failing copper washers may be getting combustion gasses into the fuel system and causing the FPR to leak despite being replaced...



The filter is obviously not 'clean' but I'm not 100% convinced...

Would combustion gasses in the fuel system not cause it to be difficult to start and/or stall out under load? Would the fuel also not be black? All the fuel I've drained so far has been bright green, same as it comes out of the bowser.

If I try and turn the vehicle on with very little in the tank (talking orange light been on for 30kms type low) the pump is noisier for the first 2-3 seconds and then settles down. Never hard to start, always starts first turn of the key, cranks maybe twice before it catches so less than a second from key turned to running. It will happily tow a trailer around, just not very fast

It's been suggested that IF it's combustion gasses that's causing the FPR to leak then it will be FUBAR ( $$$ ) although I do have my old one which may be able to be re-conditioned...

Most posts I read about the copper washers indicate hard starting, rough running, etc however my engine is the smoothest it's been in my ownership and as said, starts first turn of the key.

So, any advice? I believe JC has had some similar issues....JC, you out there?
Cheers
Muppet

Can you confirm that your EGR valve no longer operates?

There is nothing of the EGR system left. It's been totally removed.

Did you check the MAP is reading correctly? I did a test where I ran mine with both the MAF and MAP disconnected at the same time and whilst I could get up to 80kph, performance was very sluggish above this. The Td5 can compensate for one being faulty but struggles if both are faulty at the same time.

If you can save and post Nanocom data under some test conditions and this may give people some more vital info.

Been a few posts recently with people reporting a problem that sees revs limited to 3000 rpm with the fuel pump being the prime suspect. Don't recall what the outcome was.