Thread: Pulling my hair out!! (and there's scarce any left) Darn TD5

Originally Posted by Graeme

In case its of any use, the TD5 fuel filter housing is designed to extract air from the returned fuel (via a membrane) before feeding that fuel back into the pump for priority re-use.

Keith, The above comment from Graeme is why when the system gets airated by comp gasses, the fuel pump gets noisy.

Also, When I mentioned the gasses entering the fuel system, they can be blown through between the sealing washer and the injector tip, so you need to look very closely at them. It may not look obvious at a quick glance.

I would also add the other possibility is that you DO have low fuel pressure. I'm not certain that the D1 V8i fuel pump is up to pumping what amounts to a higher viscosity fluid through the system at high pressures for all that long?
But, if you are using winter grade diesel, then maybe I'm barking up the wrong tree...Still, have you got another pump to try? And does the engine run/ start if you spray a mist of diesel into the intake? This will at least then eliminate any mechanical issues.

JC

That's a good point about the aerated fuel. The Disco gasser pump does send fuel right back for immediate re-use that could mack the pump cranky but then again when the petrol is returned it is also aerated although due to viscosity the air might "settle out" quicker.
We do use winter blended fuels around here, the fuel in teh car would be a winter blend but as they change blends around September. Initially I thought that could have been a problem but bad fuel won't kill the thing completely.

As for spraying some fuel down it's throat, I didn't mess with that too much before, when I did It would jump and lurch a bit like it was trying but I decided to wait on the long awaited Nanocom to tell me more.

I've ordered an up rated pump (used in late model dodge and ford Diesel trucks) it's relief is set at 85 pounds and flows plenty for a 3.4-6.0L diesel so it should be plenty (hope it's not too much!) I'll pick it up tonight.

After pulling the pump I'll have a look at what the return fuel might be doing aeration wise as well.

If that doesn't work I guess I'll pull the injectors, they all click on demand but the could perhaps be leaking as Justin says. A couple of questions about this. If the injector seals are leaking wouldn't I smell diesel in the sump or on the stick? Also woudl this completely keep the motor from running at all?

Oh and inspection shows that the head hasn't moved at least while I've had it, after reading about this problem a couple "witness marks" head to block were added to help see if ever a problem developed.

Aside frome these basics, there are the other more ominous ones like broken bits in the engine. Aside from blown head gaskets has anyone seen other more catastophic failures? (not sure I want to know really)

Again thanks to you all for your replys I'm absorbing and utilizing them all as I move forward.

Originally Posted by garrycol

While I accept this can be an issue - I do not understand how these can collapse. These intercooler hoses are downstream from the turbo so are under pressure not suction - even with the engine sucking the pressure in these hoses should be substantially great than atmospheric.

Not understood.

Cheers

Garry

The hose immediately downstream from the turbo fails from the air exiting the turbo eroding it. I have had 2 fail but they just cracked and got a hole in them. It is possible for the inner layers of the hose to delaminate from the rest and baloon under pressure restricting the hose.
Regards,
Tote

Originally Posted by Slunnie

Hi Garry,

I understand where you are coming from in terms of the hose being sucked closed. I'm not sure if that is the scenario though, I've assumed that inner detaches and when it picks up air between it and the outer from seperation, that then causes a partial blockage.

Thanks - I appreciate that it is a problem with older engines and that it does happen but the physics of why escapes me.

My freelander is getting on a bit and I have a very long and soggy rubber pipe from the intercooler and I often wonder if I have the same issue. I am thinking of replacing it with a silicon one.

Cheers

Garry

Just a quick update..

The parts shop brought in the wrong fuel pump so I'll have to wait till this evening to pick it up. I did however check the flow of my existing pump to see if there was any aeration on the return line. I popped the return hose off and slipped in a bit of tubing and pumped into a milk bottle. Clean as a whistle no bubbles, a smooth stream. When cranking the engine you can see obvious interuptions in the flow. This doesn't mean the pump is providing enough pressue but haveing flow back to the tank tells me there is fuel for the injectors to use.
I also did a quick "eyeball" to see if the timing chain had slipped, seems that is in good order.

On the mechanical end I sprayed some ether (lots) and some diesel down it's throat and tried to get a bang or two with no luck. It rattled a lot and once fueled you could see the RPM's increase as the engine tried to help the starter motor but no fire.
I didn't see any bubbles in the recovery tank although I'm not sure I could crank it long enough to get and combustion air out to that part of the water system. Additionally there is no evidence of leaking (amazing really..) of oil, fuel or coolant at the seem between the block and the head.

Quite a mystery..

I'll play with it more on the weekend, Sunday will be a balmy -16c all day Saturday will be closer to 0 at -8.. Heck it hard enough starting a running diesel in the weather let alone trouble shoot an unhappy one..

the td5 not starting on ether may not be a bad thing... IVe had problems trying to ether start intercooled turbo petrol engines that once left to sit for 20 minutes have then fired up....

I think....

the intercooler slows then sperates the ether out of the air too much you then get a couple of pots of about the right mix but then its either too thin or too thick for combustion (especially if the normal fuels going in as well) when the engine cranks up the extra airflow then draws the rest out of the intercooler and after that your back to normal...

or It might just be somehting about the engine I was working on didnt want to play with an ether mix but was happy to go later due to some intermittant gremlin having gone away of its own accord.

Originally Posted by revor

I've ordered an up rated pump (used in late model dodge and ford Diesel trucks) it's relief is set at 85 pounds and flows plenty for a 3.4-6.0L diesel so it should be plenty (hope it's not too much!) I'll pick it up tonight.

The pressure should be almost 4 bar / 58 psi, and can be checked by replacing the fuel temp sensor with an appropriate nipple etc.

Have you tried unplugging the MAP/IAT sensor? Its unlikely to be the cause but easy to try.