P38 Diesel PSI tuning box. Hot/cold start problems

Hi Folks

Been having some hot/cold start problems over the last week or so. Started fine after a long period without running (overnight) and now seems to be taking a few turns to start from cold. Also when hot its nearly flattening the battery and feels like not all cylinders are firing.

After scouring the forums i'm going to try the hot start fix kit and stick in some new glow plugs to see if that helps before delving deeper.

However when under the bonnet i found it has a PSI power box fitted, i know these pretty much over fuel the car so wondering if the box might be part of the problem? Can these just be unplugged or is it not that simple

The car has also had recent spill pipes

Any info appreciated!

Cheers

Kev

Yes, you can just remove the Power Box and reconnect the loom direct to the FIP.
Is the cranking speed good?
In tank pump is another possibility especially if the tank is less than a quarter full.

Cold start problems are usually a couple of glow plugs down. Could be ECU temp sensor duff that would contribute to both hot and cold start problems. Timing modulation out. (Injection pump static timing) will give hot starting problems.

Datatek said:

Yes, you can just remove the Power Box and reconnect the loom direct to the FIP.
Is the cranking speed good?
In tank pump is another possibility especially if the tank is less than a quarter full.

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Crank speed is fine. It os low on fuel though!

Keviswatt said:

Crank speed is fine. It os low on fuel though!

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if it is less than a 1/4 of a tank of fuel and the pump in the tank is cracked it will not supply enough fuel.common fault on p38's.

gemsdad said:

if it is less than a 1/4 of a tank of fuel and the pump in the tank is cracked it will not supply enough fuel.common fault on p38's.

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^^^^^^ Check the in tank pump is working.

Datatek said:

^^^^^^ Check the in tank pump is working.

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yes sorry.

gemsdad said:

yes sorry.

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No need for sorry, the pipes crack too

All has been well since filling up with fuel. I guess the pumps fooked then!

Keviswatt said:

All has been well since filling up with fuel. I guess the pumps fooked then!

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Yep, in tank pump fecked.

Hear we go again
You can replace the intank pump by cutting a access hole under the rear seat but I strongly recommend that you drop the fuel tank!
That way you can check the break pipes normally hidden above the tank that are probably the originals

Keviswatt said:

Hi Folks

Been having some hot/cold start problems over the last week or so. Started fine after a long period without running (overnight) and now seems to be taking a few turns to start from cold. Also when hot its nearly flattening the battery and feels like not all cylinders are firing.

After scouring the forums i'm going to try the hot start fix kit and stick in some new glow plugs to see if that helps before delving deeper.

However when under the bonnet i found it has a PSI power box fitted, i know these pretty much over fuel the car so wondering if the box might be part of the problem? Can these just be unplugged or is it not that simple

The car has also had recent spill pipes

Any info appreciated!

Cheers

Kev

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Hi Kev,
I hasd similar problems to yourself. I have a PSI Power Box fitted on mine too, but as it turns out it is not the problem. Firstly, with the ignition switched off, disconnect the round PSI Power Box connector with I think 7 pins, clean up the pins give it a good shot of WD40 and re-assemble, then have the diesel pump timing checked, if the drive chain has stretched a bit it will need doing. It is the primary cause of poor starting when hot! If your cold starting is also poor, change the glow plugs, a reasonably cheap repair all in all! One last thing to check your battery - it should be a type 664 with about 110amp hour output, I had a swish Bosch silver 85 amp hour battery in mine when I bought it - as much use as a chocolate teapot, changed it for the proper rated one and most of my electrical glitches disappeared.

P38tyro said:

Hi Kev,
I hasd similar problems to yourself. I have a PSI Power Box fitted on mine too, but as it turns out it is not the problem. Firstly, with the ignition switched off, disconnect the round PSI Power Box connector with I think 7 pins, clean up the pins give it a good shot of WD40 and re-assemble, then have the diesel pump timing checked, if the drive chain has stretched a bit it will need doing. It is the primary cause of poor starting when hot! If your cold starting is also poor, change the glow plugs, a reasonably cheap repair all in all! One last thing to check your battery - it should be a type 664 with about 110amp hour output, I had a swish Bosch silver 85 amp hour battery in mine when I bought it - as much use as a chocolate teapot, changed it for the proper rated one and most of my electrical glitches disappeared.

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DONT mention WD40 for cleaning electrical connections on this forum unless you have very thick skin

another source of starting problems is the diesel return hoses between the injectors , if leaking ther will be air in the fuel system , fitted new ones one my 1998 , and now "she" starts fine everytime-

Datatek said:

Yep, in tank pump fecked.

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Should i be concerned or will it run away as long as i keep it full of fuel?

Keviswatt said:

Should i be concerned or will it run away as long as i keep it full of fuel?

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Replace it ASAP or it will catch you out, the FIP was not designed as a suction pump.

Thanks folks. This sounds like a pain in the arse. Anyone wanna do it for me ....lol