RangeRovers.net Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
132 Posts
Discussion Starter #1
Gentlemen, your assistance please. My 4.6HSE has an intermittent starting problem. Only when warm. It fails to start instantly ,as usual, and continued cranking does no good. But if I hold the throttle fully open and keep cranking ,it eventually fires for a moment. Repeated attempts (between 3 and 6) will ultimately result in the motor bursting into life as if nothing happened, although all this is accompanied by large clouds of black smoke. Any ideas please?
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
148 Posts
The black smoke would be caused by the fuel entering the combustion chamber when you are putting the accelerator to the floor and cranking it I would imagine. How's the temperature in South Africa at the moment. The reason I ask is that I used to have a car with a similar problem which was caused by fuel vapourizing in the lines because it was getting too hot under the bonnet. Mind you Rangies seem to be freaking hot under there no matter where you are. Maybe the fuel pump/filter is blocked and not letting enough fuel through on start up. Just a thought, but it will give you a couple of places to look. :)
 

·
FOUNDING MEMBER
2006-2009 Range Rover Sport
Joined
·
233 Posts
pistonbroke,

I tend to agree with rich998a, it could be a sensor problem.
Whatever error there is, is forcing the fuel system towards rich, as confirmed by the black smoke and the car finally starting with the flooded motor technique.
This error of course would work in your favour on cold starts, hence no problems then, but bad news when hot.

Another possibility is that it could also be a sign of a fading or under-rated battery.

Next time it fails to start hot, try turning the ignition key only to the on position first, and then holding that position for some 5 to 10 seconds before turning the key to the cranking position.
If it then starts correctly, it may give us some additional clues.

This little test allows all sensors and systems time to stablize when the sensors are energized at full battery volts, not at cranking volts.
Some sensor inputs, such as the engine temperature, are heavily filtered via quite long time constants so as to eliminate spurious readings.
Of course once the motor is running, the alternator ensures that full volts are available, and no more problems.

How old is your battery, and is it rated correctly with regard to the cranking amps needed for the P38?

Cheers
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
Fuel rail sensor ?
Breather pipes not cracked, vent restrictor still in steel tube on right rocker cover
Idle control valve
Worn out HT leads, when hot HT leads become more conductive on the outside and allows spark leakage to earth
Use genuine LR HT leads costs around R150 per lead, replace as a complete set
Use correct Champion spark plugs, I tried all sorts and the Champions are the ones to use, average R48 per plug
you might have a bad seal on cover to intake ram tube stack assembly.

I can add many items but the obvious needs to be investigated first
 

·
Registered
Joined
·
16 Posts
Hi.
I had this problem before and changed every sensor and H/T leeds and fuel reg. and you know what it was?
Fuel injectors but everyone was talking about sensors .
Please check if injectors are a "ok"
Jerry
 

·
Premium Member
2010-2012 Range Rover MkIII / L322
Joined
·
4,635 Posts
It just goes to show how a short diagnostic session can sort out a problem saving hundreds of pounds.
 

·
Registered
Joined
·
132 Posts
Discussion Starter #9
At the risk of speaking too soon, I think we have it licked. Coolant temp. sensor faulty, but only intermittently.
Connected my Proscan and got only code P1177. However ,when I watched the temp sensor in live time, it read normally for a while ,then suddenly went to -40C. Impossible! Ohmeter showed open circuit and that was that. I gather code P1177 is Maximum Negative FMFR Correction Fault, which apparently means the system is running so rich the ECU has reached its limit of correction. Is this correct and what does FMFR stand for?
 
1 - 9 of 9 Posts
Top