P38A Diesel engine probs

Datatek · Jul 4, 2019

RangeRoller dt said:
It’s sometimes added as an aftermarket modification to earlier models or to hide fuelling problems.

Started off with a thread on here years ago. Ended up £35 on eBay everywhere

Hot starting problems, not fuelling problems.

RangeRoller dt · Jul 4, 2019

I was referring to fitting hotstart to mask FIP issues.
I may have to do this funnily enough

Datatek · Jul 4, 2019

RangeRoller dt said:
I was referring to fitting hotstart to mask FIP issues.
I may have to do this funnily enough

It does not "mask FIP issues" it overcomes worn chains or some say a design fault in that there is not mixture enrichment on a hot start, it does this by fooling the EDC into thinking the engine is cold.

Datatek · Jul 4, 2019

wammers said:
Idle should be rock steady 750 RPM. May vary + or - 50 as loads are applied and removed. But auto idle control should return it to 750. Auto idle control should react instantly to drops or rises in idle speed. Problem with stalling from idle is that if the idle RPM drops below 500 RPM or the wiper loses contact with the pot the engine will stop. This is usually caused by the quantity servo feedback wiper losing contact with the feedback pot. If the wiper loses contact with the pot at any speed and the ECU does not know the servo position, the stop solenoid drops.

RAVE says 750+/- 50 no mention of variance with load which should be compensated for by the EDC.

Grrrrrr · Jul 4, 2019

Dieselmech said:
Not sure, how would I know?

Hot start normally on side of battery box somewhere. Only needed on earlier cars. A mix of factors caused hot starting issues on earlier cars when the chains stretched and the starter motor didn't go around as fast. Fixed on later models by less optimistic values in the engine ECU and running the lift-pump while cranking.

As data says, the hot-start fix fools engine into thinking engine is cold so it brings the glow-plugs on (even though hot) and squirts more fuel in. That's normally enough to let it catch.

Here's mine. Little box to the right.

Datatek · Jul 4, 2019

Grrrrrr said:
Hot start normally on side of battery box somewhere. Only needed on earlier cars. A mix of factors caused hot starting issues on earlier cars when the chains stretched and the starter motor didn't go around as fast. Fixed on later models by less optimistic values in the engine ECU and running the lift-pump while cranking.

As data says, the hot-start fix fools engine into thinking engine is cold so it brings the glow-plugs on (even though hot) and squirts more fuel in. That's normally enough to let it catch.

I can assure you that the hot start fix is needed on later cars, my project car with stretched chains needs a lot of cranking to start when hot. It's not going to get a hot start fix, it is going to get the timing adjusted.

Dieselmech · Jul 4, 2019

My car has 148k on the clock and starts like a goodun. Its the stalling that's my problem at the moment. Only time starting was an issue was when the leak offs cracked and let the fuel run back and the lift pump went sticky.

RangeRoller dt · Jul 4, 2019

mine cuts out when hot if you stop suddenly, like at lights or someone pulls out in front of you.
Turning the wheel when stationary causing it to die is the final sign.

wammers · Jul 5, 2019

Datatek said:
It does not "mask FIP issues" it overcomes worn chains or some say a design fault in that there is not mixture enrichment on a hot start, it does this by fooling the EDC into thinking the engine is cold.

Yes it does, so cold start fuel is set, so the fuel quantity is increased.

wammers · Jul 5, 2019

If you have cruise control the very first sign of an impending quantity servo problem is the MIL lamp flicking on then off when cruise is disengaged.

Grrrrrr · Jul 5, 2019

wammers said:
Yes it does, so cold start fuel is set, so the fuel quantity is increased.

Oh no it doesn't!

Oh yes it does!

Watch out! He's behind you!

wammers · Jul 5, 2019

Grrrrrr said:
Oh no it doesn't!

Oh yes it does!

Watch out! He's behind you!

Don't you start.

RangeRoller dt · Jul 5, 2019

Does good job of hiding chain slack too

until you forget to sort it and jump a cog or worse.
@Musicmaker was lucky got away with doing chains after jumping a cog.

Dieselmech · Jul 5, 2019

wammers said:
If you have cruise control the very first sign of an impending quantity servo problem is the MIL lamp flicking on then off when cruise is disengaged.

I'll see if it has cruise and try it. Not sure if it does have cruise control.

RangeRoller dt · Jul 5, 2019

Think it’s on the stalk for indicators. (Two knobs on end same as wiper washers other side)
mine are blanked so guess that’s what they are?

If you do have it, make sure it is working before counting on it’s diagnosis.

Grrrrrr · Jul 5, 2019

Dieselmech said:
I'll see if it has cruise and try it. Not sure if it does have cruise control.

Button on the dash for mine ... or would be if I had it. I have the button but it is for my front parking sensors.

Datatek · Jul 5, 2019

Grrrrrr said:
Button on the dash for mine ... or would be if I had it. I have the button but it is for my front parking sensors.

Button on the dash is the master switch, set and resume buttons are on the steering wheel.

Datatek · Jul 5, 2019

RangeRoller dt said:
Think it’s on the stalk for indicators. (Two knobs on end same as wiper washers other side)
mine are blanked so guess that’s what they are?

If you do have it, make sure it is working before counting on it’s diagnosis.

The 2 buttons on the indicator stalk are one for cycling through message centre display options, the other allows a speed alarm to be set.

Dieselmech · Jul 8, 2019

Just as an update the diesel shop I use has offered to remove the pump and send it back. (its the second time the pump has been off as the stop solenoid malfunctioned after about 100 miles and it was sent back then). Will update after the work has been done.

wammers · Jul 8, 2019

Dieselmech said:
Just as an update the diesel shop I use has offered to remove the pump and send it back. (its the second time the pump has been off as the stop solenoid malfunctioned after about 100 miles and it was sent back then). Will update after the work has been done.

It sounds like the refurb place do minimal refurbishment using old parts. When refurbing a pump a new quantity servo is a must.

P38A Diesel engine probs

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