Diesel Hot Starting Fault P38

What revs does your engine idle at?

wammers said:

ECM. Engine control module. Mpg is about right around town.

Click to expand...

Never got mine down to 19mpg even towing the caravan in the Pennines

Datatek said:

Never got mine down to 19mpg even towing the caravan in the Pennines

Click to expand...

Around town stop start, more stop than start, i get around 19-20 on a run up to 30. It's done 110,000 on as far as i know same injectors. So am looking to get injectors refurbed by Diesel Bob before the 20% vat comes in. That will keep it just below the £200.00 for all six to be done, that should make things a little better. The fact that my fuel gauge is all over the place around the half full mark cannot help the trip computer.

hot start kit fixed my problem,proper kit with timed relay took about 20 minutes to fit.kit cost £46 inc v.a.t,does anyone have an owners manual,mine came without one,where can i get one from?

roddy4 said:

hot start kit fixed my problem,proper kit with timed relay took about 20 minutes to fit.kit cost £46 inc v.a.t,does anyone have an owners manual,mine came without one,where can i get one from?

Click to expand...

Download the RAVE CD from gree-oval.com - the owners manual is in plus everything else you will need.

cheers magictiny,i am on it.

Hi all frustrated hot start victims, I have become familiar in the 2months of ownership of a 95 Dt, it need a bit of tidying but not much corrosion so i am happy to give it tlc. It was last Sat i got to put tigapiglets fix on it. It does the job but idles higher and is smoky.

So I read all of this thread and came to a new fix based on mention of possible temp sensor failure.

This involves eliminating the solenoid and diode and connecting wires to the ends of the grey/blue wire. These extend into the dash area and are fitted with a normally closed push button or a spring toggle.

When the engine is hot you press the switch before turning the key, which will give you the glow plugs, after starting release button and everything is normal again.
It works for me.

I know it is perhaps equivalent to fitting a timer to tigapiglets circuit which would be the auto version.

Hi There MG Mayo,
Yep I can see how yours is a simplified method. if you used a timer relay - mentioned in my posts it works when hot and also gives extra cold start assistance for the amount of time you preset it to all without holding the button.
Yours is by far the cheaper option though.

As anyone observed enginer "judder" after installing a Hot Start Fix (the proper one, with the 30 second timer)?
I installed mine today and it is working as advertised, glow plugs always come on with key in position II even with the motor at running temperature. But in the afternoon, after a long run, I stopped and restarted the engine, and it started to behave erratically, with a very inconsistent tickover, dropping bellow 700rpm. Could this be related to overfuelling (the ECM sends more diesel thinking the engine is cold)?
If this happens again I'm going to let it idle like that until the 30 seconds are over, to see if it gets back to normal after the box as disabled itself.

Cheers!

I am going to try this very soon,
When the ignition is turned on the relay will energise sending the temp signal through term 87 and the resistor making the ECU think the enginge is cold, as soon as the engine is running and the alternter is charging the wire connected to term 85 will change from negative to 12v causing the relay to de energise sending the temp signal through term 87a therefore bypassing the resistor and sending the correct temp signal to the ECU .

New to the forum and just been reading through all of this thread.

If disconnecting the coolant temp sensor works as far as getting the car started when hot, wouldnt an in-line switch on the sensors wiring be the easiest way of sorting this?

Hi Doncarlion, a switch disconnecting the sensor makes the ECU adopts a failsafe setting which equals slightly warm and doesn't fully remove the issue. By switching the feed through a resistor either via a timed relay or by a relay switched through the alternator charging signal automatically tells the engine its cold when hot- and really cold if cold.
Several people have advised that the issue is down to fuel pump timing and stretched timing chains, but I know of people who have had the pump reconditioned and retimed still having the problem. - out of interest what is the mileage of your P38?

Cheers

wantaquad said:

Hi Doncarlion, a switch disconnecting the sensor makes the ECU adopts a failsafe setting which equals slightly warm and doesn't fully remove the issue. By switching the feed through a resistor either via a timed relay or by a relay switched through the alternator charging signal automatically tells the engine its cold when hot- and really cold if cold.
Several people have advised that the issue is down to fuel pump timing and stretched timing chains, but I know of people who have had the pump reconditioned and retimed still having the problem. - out of interest what is the mileage of your P38?

Cheers

Click to expand...

Hi Mate

Its not actually mine its my girlfriends dads car, but i was going to be purchasing the hot fix kit off ebay and was dubious... so thought I would read into it a bit more.

So with what you are saying, would an in-line switch on the alternator charging signal not do the same thing as the relay? Or is the whole point that you need a lower signal rather than remove the signal?

doncarlyon said:

Hi Mate

Its not actually mine its my girlfriends dads car, but i was going to be purchasing the hot fix kit off ebay and was dubious... so thought I would read into it a bit more.

So with what you are saying, would an in-line switch on the alternator charging signal not do the same thing as the relay? Or is the whole point that you need a lower signal rather than remove the signal?

Click to expand...

You really are going to knacker something up big time.

doncarlyon said:

Hi Mate

Its not actually mine its my girlfriends dads car, but i was going to be purchasing the hot fix kit off ebay and was dubious... so thought I would read into it a bit more.

So with what you are saying, would an in-line switch on the alternator charging signal not do the same thing as the relay? Or is the whole point that you need a lower signal rather than remove the signal?

Click to expand...

You need the resistance to emulate the temperature sensor which is a negative coefficient resistor. A direct connection from the alternator is not the same.

The hot start fix gives a timed heating cycle

wammers said:

You really are going to knacker something up big time.

Click to expand...

Thats ok, its not mine :bounce:

Im just looking at other ways of doing it without spending 30 odd quid on a box of tricks that is basically a switch and a resistor.

Datatek said:

You need the resistance to emulate the temperature sensor which is a negative coefficient resistor. A direct connection from the alternator is not the same.

The hot start fix gives a timed heating cycle

Click to expand...

Ok, i thought it would be something along those lines.

Thanks for the help guys!

Hi Doncarlyon,

All I used was a resitor 2kohm and a programmable relay, which treats the ignition feed as a pulse to switch the circuit through the resistor to the temp sensor and after a timed period (30 Secs) turns the circuit back through the direct line to the temp sensor.
This also gives really good cold starting too

Hi, I have added some pics to explain my earlier post. The grey/blue wire to splice is in the black box behind the battery. Cut it and to each wire attach a wire which you feed to the dash.
These extend into the dash area and are fitted with a normally closed push button or a spring toggle. I got the push button in maplin.

When the engine is hot you press the switch before turning the key, which will give you the glow plugs, after starting release button and everything is normal again.
It works for me.