P38A Diesel cold start issue

Hi,
My P38A diesel has recently developed a problem of poor starting when cold I'd appreciate advice on.
It seems to need at least two sessions on the glow plugs and several seconds (about 20+) cranking before it will fire up. Once started it's fine. I've replaced the leak off pipes but that didn't help so now I'm suspecting the glow plugs. These were replaced 4 years ago could they be giving up? I'd expect them to last longer than this. Is there any way of testing them? Any recomendation on replacement make?
Is there any else that could cause poor cold start I should be looking at? The fuel tank is at least half full.
Thanks for any help.
mikeateves

Replace the glow plugs. Maybe also ECU temp sender.

Make sure they are getting power to them, that's first step, if they are they could just be u/s

As above check the glow plugs - depending on make, they could last either 2 weeks or a few years....

Cheaper makes on the glowplugs have been known to be a bit naff - I am an advocate of getting value for money, but on some things paying a little more for a decent make will pay for itself down the line!

Hi guys,
Thanks for the quick replies and suggestions.

Have you checked if you have air in the clear pipe between the fuel filter and the injector pump?

Could be you have a leaking fuel injector which is letting air in to the system, or the in-tank fuel pump isn't working properly.

Does it start any better on a full tank of fuel? (I know you said it is at least half full).

Also, are you confident your battery is up the the job. I reckon I've got an average of 2 - 3 years out of each battery on my P38 depending what kind of usage it's had. It doesn't take much of a reduction in cranking speed before you really start to notice it. (My current battery is lasting well though, ever since I fixed the fuel injector leak which was causing poor starting and putting strain on the fuel lifter pump).

Hi,
Thanks for the replies. I finally got around to doing a bit of investigation... I connected a voltmeter +ve to glowplug terminal -ve to earth (engine block) and turned the ignition on and off and measured each glowplug. The rear 4 measured 10.5volts, the front 0volts and the next 5.5volts (approx). First I thought this showed the front two plugs were faulty but now I'm thinking it showed they weren't getting power properly. If this so, where do I go from here?
During this test I noticed when the ignition was switched of the fuel in the clear pipe drained back to the fuel filter despite having replaced the leak off pipes. Endeleus suggests a leaking injector, can I test for this, what is the fix?
Thanks,
mike

How do you know the fuel drained back to the filter? If you have bubbles in the line that is another problem you need to sort out. As fuel pump applies pressure air in line is compressed. When pump stops the air expands and pushes fuel back to filter. Bleed the line properly. Only part of an injector that can cause that are spill pipes. Each glow plug is fed separately from glow relay which is in the box behind the battery. Check the connections on the plug to it for bad contact/burning.

Thanks for the reply Wammers. As I had run the engine since changing the leak off pipes I assumed any air in the pipe would have been pumped into the engine and no longer be a problem. I didn't bleed the air out after changing the pipes so I'll do this as you suggest. Thanks for the glow plug relay advice, I'll check this next.

mikeateves said:

Thanks for the reply Wammers. As I had run the engine since changing the leak off pipes I assumed any air in the pipe would have been pumped into the engine and no longer be a problem. I didn't bleed the air out after changing the pipes so I'll do this as you suggest. Thanks for the glow plug relay advice, I'll check this next.

Click to expand...

Air just gets compressed in pump and goes nowhere unless you crack an injector open to get rid of it and/or bleed the clear pipe. Undo union on pump and get someone to switch ignition on, pump will only run with glow lamp on. So on and off until all air is gone then nip union up. Then run engine at 2000 rpm or so and crack injectors open in turn to get rid of any that is in pump.

Okay thanks.
Cracking and bleeding session coming up

mikeateves said:

Okay thanks.
Cracking up and burning the bleeding car session coming up

Click to expand...

Edited for accuracy....