P38 diesel fuelling issue?

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as far as I know its the original head! The second owner had it from 4yrs old until 2014, the third until last year and then myself.
I replaced the sensor midway down the head as it was coming apart giving false readings. There were no plugs hanging about near the back of the head.. It all functions as it should. Maybe an early 1999 registered late??
 
cpa said:
So this morning took off the hot start fix kit. Freezing cold and the glow plug light only came on for 4 seconds. Spluttered into life after turning on ignition a couple of times. Started on the button after that. For some reason the BECM must be telling it to switch off plugs prematurely. Have already replaced temp sender with new one. So I doubt it is that. I guess the BECM needs to be interrogated to find out why such a short pre-heat?
Click to expand...
when it starts up, does it cough a bit of black smoke or run calm straight away?
 
did you take a look at the engine fuel pump. I ask because mine leaks when running around the two upper caps on the inj'pump. Sometimes I get a delayed start or lumpy start. Grab a torch an take a look if it's damp there could be a leaking seal. I cleaned mine off with brake cleaner while warm and watched it slowly wet itself! Diesel out! = air in!
 
I'll take a close look. But why is the glow plug light only coming on for 4 seconds? Cycled the ignition half a dozen times this cold morning - should be coming on longer than that.
 
cpa said:
I'll take a close look. But why is the glow plug light only coming on for 4 seconds? Cycled the ignition half a dozen times this cold morning - should be coming on longer than that.
Click to expand...

As said glow plug duration is a result of the temp being fed to the engine ECU by the green temp sensor. The lower the temp the longer they are on for. If the temp sensor fails a preset of 50 degrees is used. That maybe your problem. You keep asking and keep getting answers but don't seem to be listening. ;)
 
Thou can leadeth a Horse to water but thou can't maketh it drink, Wamms.:D
I don't think he realises you are he, Da Man...

That you chose to walk among us is a comfort, even though your no bloody use to me with my invisible non L322 that I don't have, anymore....:eek::eek::D
 
Last edited:
myfirstl322 said:
Thou can leadeth a Horse to water but thou can't maketh it drink, Wamms.:D
I don't think he realises you are he, Da Man...

That you chose to walk among us is a comfort, even though your no bloody use to me with my invisible non L322 that I don't have, anymore....:eek::eek::D
Click to expand...
You can lead a horse to water but a pencil must be lead!
 
myfirstl322 said:
Thou can leadeth a Horse to water but thou can't maketh it drink, Wamms.:D
I don't think he realises you are he, Da Man...

That you chose to walk among us is a comfort, even though your no bloody use to me with my invisible non L322 that I don't have, anymore....:eek::eek::D
Click to expand...

If you read the following from RAVE, whilst it gives the info needed, it is obvious that the technical writer is a bit of a numpty. See if you can spot why i say this.

CIRCUIT OPERATION
Engine Coolant Temperature Sensor (X126)
This sensor is a ‘thermistor’ (a temperature
dependent resistor) where the voltage output varies
in proportion to coolant temperature. The ECM
(Z132) uses this information in many strategies, i.e.
to correct the injected fuel quantity and timing
(especially during cold starts), length of glow plug
timing, etc. The sensor is located in the top of the
engine block. In case of a failure, the warning lamp
is not activated and the ECM (Z132) selects a
substitute value of 50C for glow plug and ignition
timing and uses the fuel temperature to correct the
fuel quantity, glow plug timing will not be correct,
possibly resulting in long crank times in cold weather
as well as slight fuelling effects. These symptoms
may not be noticeable.
 
wammers said:
If you read the following from RAVE, whilst it gives the info needed, it is obvious that the technical writer is a bit of a numpty. See if you can spot why i say this.

CIRCUIT OPERATION
Engine Coolant Temperature Sensor (X126)
This sensor is a ‘thermistor’ (a temperature
dependent resistor) where the voltage output varies
in proportion to coolant temperature. The ECM
(Z132) uses this information in many strategies, i.e.
to correct the injected fuel quantity and timing
(especially during cold starts), length of glow plug
timing, etc. The sensor is located in the top of the
engine block. In case of a failure, the warning lamp
is not activated and the ECM (Z132) selects a
substitute value of 50C for glow plug and ignition
timing and uses the fuel temperature to correct the
fuel quantity, glow plug timing will not be correct,
possibly resulting in long crank times in cold weather
as well as slight fuelling effects. These symptoms
may not be noticeable.
Click to expand...
Doozle is way above my pay grade....
But in for a penny in for a £ >>>>> IGNITION TIMING, should read INJECTION, especially as no mention of checking the spark plug gaps..silly beggar(cough):D
Did I get it Did I get it???
 
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myfirstl322 said:
Doozle is way above my pay grade....
But in for a penny in for a £ >>>>> IGNITION? should that not read Injection?
Click to expand...

Yes it should and also describes the position of the sensor for a petrol engine. On a cold start the diesel engine injection timing is always at static advance. That cannot change until the engine is running and there is internal pressure in the injection pump. He is getting mixed up with a petrol engine. Just as in the description of how the MAF sensor works, implying injected fuel quantity is down to airflow, which it isn't on the diesel, but is on the petrols. No wonder people read that and not understanding that it cannot be, come up with some fanciful ideas.
 
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The OP may also like to remove the glow relay and check for loose connectors to power supply and burned loose connections to the glow leads, for his low voltage issue. .
 
cpa said:
So this morning took off the hot start fix kit. Freezing cold and the glow plug light only came on for 4 seconds. Spluttered into life after turning on ignition a couple of times. Started on the button after that. For some reason the BECM must be telling it to switch off plugs prematurely. Have already replaced temp sender with new one. So I doubt it is that. I guess the BECM needs to be interrogated to find out why such a short pre-heat?
Click to expand...

Just a thought on this. When you removed the hot fix you did of course remake the connection to the Grey/Blue wire that is cut to connect the hot fix. If you didn't the circuit to the temp sensor and fuel temp sensor for ECU is open circuit. And you will be using the 50 degree preset which would maybe give you 4 or 5 seconds of glow lamps.
 
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