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

Okay then, the Holidays are over and the weather much better.

I fiddled a bit with the truck today. Fuel pressure on the delivery side is
75 PSI, on the return side with the return line blocked by the gauge there is also 75psi. When I crank the engine the pressure on the return line gauge will go down as if it's using fuel. If I just pump it up and leave it be (no cranking) it will stay a 75psi all day long so that would indicate no leaks.

I also did the stethescope with a wire in the hose trick and confirm that the electronics are firing the injectors CLICK,CLICK,CLICK. Same noise when testing with the nanocom. She still won't fire..

????????????

crank position sensor?

You will have to get one of the mechanics on the forum to give you more info on diagnosis method. I just recall that that is one thing that will prevent a TD5 from firing.

Originally Posted by slug_burner

crank position sensor?

You will have to get one of the mechanics on the forum to give you more info on diagnosis method. I just recall that that is one thing that will prevent a TD5 from firing.

The CPS has been replaced, although on the Nanocom there was a reading of RPM. Doesn't hurt to have a spare.

Hi Keith!

I just had a problem with a Td5 130 Defender non starting after being towed in with a dud fuel pump. I replaced the pump (after cutting a hatch through the tray floor..couldn't economically remove the tank as the vehicle has a spare wheel carrier WELDED to the rear crossmember and bolted to the towbar and as such can't remove the tow bar and obviously the tank bla bla...)It would crank over at a reasonable rate and after about 10 seconds the check engine lamp would illuminate and a 'noisy crank signal' code would appear. To check the crank angle sensor I substituted a known working example, connected an extra battery and still no go. After a few more tests with the loom etc I discovered the starter would get INCREDIBLY hot after only a few cranks, IE excessive heat and resistance seemed to be the problem. The contacts for the solenoid on examination were burnt very badly. Upon replacing them and dismantling/ cleaning the starter brushes and commutator I refitted it and INSTANTLY started. The starter was full of oilly residue and diesel mist from a leaking fuel regulator that had apparently been replaced some time ago. The cranking speed was about double, and there is no more electrical noise from a labouring starter inducing a fault code.

The earth leads and everything else were perfect, the vehicle is a 2002 model with only 100K on the clock, there were no other symptoms from the starter other than turning slightly slower than you would expect. No clicking, no outright failures, just too much internal resistance causing excessive volt drop during cranking.

Hope this helps!

JC

I'll give it a look! I'm grabbing for anything at this point!

Not getting any bad codes like that but it's worth a go.

Did you have the means to see what the cranking RPM was on the truck? I'm seeing about 300 to 325 on a good battery. It's showing about 11.6 Volts while cranking.

That doesn't explain why it shut down in the first place but that may have been solved and I just don't know it..

I'll see what happens tomorrow and I'll let you know!

Originally Posted by revor

... When I crank the engine the pressure on the return line gauge will go down as if it's using fuel....

Any chance this pressure drop is due to reduced voltage at the pump, rather than the fuel being used? The standard pump and pressure regulator should be able to maintain approx 60psi at full engine revs, let alone just turning over, although the lower pump voltage whilst cranking may be able to cause the pressure to lower.

I would not assume that fuel is getting through that gauze filter without knowing that fuel is returning from the head return passage.

Edit: You could try a low pressure pump (less than the regulator pressure) to see if fuel returns from the return line while the pump is running to prove that the gauze is not blocked.

Originally Posted by Graeme

Any chance this pressure drop is due to reduced voltage at the pump, rather than the fuel being used? The standard pump and pressure regulator should be able to maintain approx 60psi at full engine revs, let alone just turning over, although the lower pump voltage whilst cranking may be able to cause the pressure to lower.

I would not assume that fuel is getting through that gauze filter without knowing that fuel is returning from the head return passage.

Edit: You could try a low pressure pump (less than the regulator pressure) to see if fuel returns from the return line while the pump is running to prove that the gauze is not blocked.

I see what you're saying Graeme but "i think" i have have that covered. I'll explain the setup better.


Initially I made an adaptor to fit the fuel delivery line directly to the fuel pressure gauge and achived 75PSI by manually making th fuel pump run. The check valve in the fuel pump would hold the pressure all day if I let it.
I reconnected the pressure line to the regulator.

Then I disconnected the return line from the regulator and using the proper fitting I connected the pressure gauge to the regulator. Again I manually made the fuel pump run to 75PSI. In this setup it also seemed as if it would hold that pressure all day long if I let it.

Next, with 75PSI on the gauge in the return line and the fuel pump relay removed I watched the pressure drop while cranking the engine. a 30 second crank would reduce the pressure on the gauge to about 55-60PSI the more I cranked the more it would go down.

To me this test seems to prove a few things:
First, the fuel pump can develop at least what the engine needs to keep running or even start.
Next the fuel can come out of head at high pressure as well and hold it, indicating there is not a crack in the fuel rail drillings.


Lastly the injectors seem to be using the fuel in the rail when we crank it.

Previous flow tests at the return line at the tank showed that the fuel pump output was enough to do better than a couple of liter's per minute (filled a half gallon milk jug in no time.)

Does this testing hold water?

Originally Posted by revor

I see what you're saying Graeme but "i think" i have have that covered. I'll explain the setup better.


Initially I made an adaptor to fit the fuel delivery line directly to the fuel pressure gauge and achived 75PSI by manually making th fuel pump run. The check valve in the fuel pump would hold the pressure all day if I let it.
I reconnected the pressure line to the regulator.

Then I disconnected the return line from the regulator and using the proper fitting I connected the pressure gauge to the regulator. Again I manually made the fuel pump run to 75PSI. In this setup it also seemed as if it would hold that pressure all day long if I let it.

Next, with 75PSI on the gauge in the return line and the fuel pump relay removed I watched the pressure drop while cranking the engine. a 30 second crank would reduce the pressure on the gauge to about 55-60PSI the more I cranked the more it would go down.

To me this test seems to prove a few things:
First, the fuel pump can develop at least what the engine needs to keep running or even start.
Next the fuel can come out of head at high pressure as well and hold it, indicating there is not a crack in the fuel rail drillings.


Lastly the injectors seem to be using the fuel in the rail when we crank it.

Previous flow tests at the return line at the tank showed that the fuel pump output was enough to do better than a couple of liter's per minute (filled a half gallon milk jug in no time.)

Does this testing hold water?

Have you considered that you may have holed a piston (or 2), take out the glow plugs and crank it over and see what comes out, plug in a Diesel compression tester and check your compression, I hope I'm wrong, Regards Frank.