P38A Diesel engine probs

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
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.
 
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.

20120713-2034_NokiaE3213072012(001).jpg
 
Last edited:
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.
 
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.
 
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.
 
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.
 
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.
 
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.
 
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.
 
Back
Top