Starting a P38: Cold vs Warm

Hello again

Quick one I hope, when starting the Range first thing in the morning with the engine on idle it starts first time (or if left during the day to cool down). When warm however, the accelorator has to be half depressed for a second time start, not doing this leads to many turnovers until diesel is introduced.

As a Range novice is this to be expected as I kind of figured that the hotter the engine the easier it is to start?

Apologies if I should know better

Cheers

Adam

Hi Adam,

I too was in your position last year. Deep in these forums you will find the answer. There is an issue with warm starting. Basically, once the engine starts to get warm, the CPU doesn't use the heater plugs etc. when starting. That's why it is OK when cold and OK when hot.

The fix is to put a 2k ohm resister in series with the engine temp sensor wire, but not to leave it in circuit all the time, otherwise it would be like driving round with the choke on (if you can remeber those days). Therefore you need a timer relay to put the 2k in line for the 30 seconds of starting, then short it out for normal running.

The easy way is to buy a ready made kit from Ebay (as I did). Search for P38 Hot Starting Fix, on Ebay and pay the £29. Simple to fit.

Hope this helps.

Hi PIN

thanks for that, have Ebay'ed the suggestion and read the description where it says "and parts required to make this simple modification". Are there many, expensive etc?

Cheers

Adam

Hi

Another thought, is it that the sensor calibration is out and detects a warm engine (warm enough to switch off the heater elements) when in fact the temperature reading is accurate but the application of it is not?

Cheers

Adam

Hi Adam,

Not sure about the calibration issue, I thought it might have been designed that way due to emmissions, or even economy. I do know it is a common problem with the 2.5 BMW engine. When I researched it last year there were loads of threads about this issue. I bought the kit off of Ebay (cheaper than building your own), which is a box of electronics with 4 wires coming out, power (switched though ignition), earth, and the in & out from the temp sender. You get good instructions to help you connect it, with pictures on the website.
I have since fitted 2 more to friends P38s.

Good luck.
Paul