STARTING WOES

[peasey]

morning all , just thought i would give you all sothing to think about while at work today to keep you from getting bored!!!!!now i have recently bought a 96 n plate v8 disco and im well pleased even though it has a few probs, small ones but all the same a little annoying!!!right this is the worst one im getting my ear bent about.when starting she starts real quick and the revs rise to around 2k then drop to feck all and she stalls,when restarting it again it starts spot on but the revs rise to 2k and then drop to about 250. it will then rise and fall between 1k and 250 until you rev it and the thing that worries me is that it does it when its hot or cold. now i have changed the leads the coil the air filter the plugs dizzy cap and rotor arm and its still the same?any ideas lads (and before you say maf plug i have checked that)cheers paul

[shaun and co]

had a similar problem once- there was a tiny hole in the fuel pipe so fuel was draining back into the tank when the truck stopped and air was replacing it. the whole was so small though that air could get in but fuel couldn't get out so there was no tell tale leak.

[greasemonkey]

Hi being an N reg it will be fuel injected
therefore will have a temp sensor
this will set the fuel amount depending on temp of engine
if knackered will cause this fault by either over fueling (revving)
then the lambda says too much fuel and cuts it out (dying)
replace sensor all will be well
cheers
GM

[peasey]

ah mate that sounds spot on and to be honest i have checked every thing i can think of except that!! i dont suppose you know where abouts it is do you mate cause i cant find it in the haynes manual.is it the thing that bolts to the side of the aluminum 3.9 inlet manifold?

[greasemonkey]

HI mate
sorry a vx persom i am just going for the engineering answer
but it will be on the water temp side
so look by the thermostat etc
cheers
steve

[petergalileo]

the fuel injected V8s rely on the temperature sensor to activate the equivalent of the choke I think so thats worth checking.  I had a 3.5 V8 where the ignition amplifier played up and caused similar problems but in addition if you tried to rev it, it would get to 1500 RPM then cough and splutter like crazy then cut out.

[greasemonkey]

HI Peter
thats what i said
do you know where it is on the engine
cheers
GM

[petergalileo]

If memory serves its the one on the casting at the engine end of the top hose.  But my memory has been affected by 5 kids, a wife and a 1.8 K series Freelander so may be wrong.

[peasey]

cheers mate just where i thought it was now i might be pushing my luck here but is there anyway of checking it once its out?

[petergalileo]

Well if you want to see if it affects the starting try unplugging it and starting her up, if its the same its proberbly worth substituting for a new one.  I suppose you could test it with a multimeter set to resistance, the ohms value should drop as you get it hot but what the values are I have no idea.

[greasemonkey]

peter
you need a holiday mate
no kids no wife
lol
GM

[peasey]

cheers lads im going to try that first thing in the morning and i will let you know how i get on thanks again paul

[Range Rover Blues]

What you need mate is the Haynes manul for the RRC, not the haynes book of confusion for Discovery.  It is so much better.

IIRC the EFi temp sensor and the Temp guage sender are both just behind the thermostat.  The EFi sensor is the one with 2 wires.

My Haynesmanual tells me all the resistor values and goes through a set of tests to diagnose basic faults with all the EFi sensors and controls.  A very good place to start.

If you are still struggling I have a copy of Rovacom if you live nearby.

[petergalileo]

Noticed you are in Essex, If you get stuck or want a diagnostic tlmlandrovers.co.uk in Tendring have one.  I am in Clacton if you get stuck.

[peasey]

right lads this is what i have done so far i have checked every vac hose and jesus theres a lot and all are fine i have checked the resistance on the fuel thermistor and it seems to work i have checked the throtle postion thing at the front of the inlet manifold and all assciated wiring and fixed my cruise control while i was there unknowingly!!!!!!! but i still get the same problem of the staling on the first turn of starting and then she starts but the revs rise and fall from 900 to 250 until you rev her? thats it im fresh out of ideas now is this somthing that i am just going to have to live with or does she have to go in to land rovers for an operation(££££)???

[petergalileo]

Give TLM a ring on 01255 830331 they charge around £30 to plug it in to their diagnostic.   They are located in Tendring, between Colchester and Harwich.  

I am pretty sure the 3.9 has a MAF or similar which is a sensor on the air intake that measures the volume of air entering the injection system, they can get mucky and give false readings to the ECU, they are very, very fragile though so clean it like its made of glass.

[daveyravey]

Hi being an N reg it will be fuel injected
therefore will have a temp sensor
this will set the fuel amount depending on temp of engine
if knackered will cause this fault by either over fueling (revving)
then the lambda says too much fuel and cuts it out (dying)
replace sensor all will be well
cheers
GM

Replace the temp sender, they're not expensive £ 14,76 inc vat + postage, from rimmer bros. I need mine doing too. Maybe 15 mins work.