Hi..!! I got a Disco -96 v8 efi and its impossible to start when the engine is cold and its around +-0 or colder outside. But if i put the motor heater on it will start. I have changed the temperature sensors but it didnt help. Any sugesstions what it could be...???

 

Does your truck have an OBDII port under the dash? A scanner plugged in may show data from these sensors and others that could indicate one is way out of specification. Assume you mean turns over, has spark, has fuel pressure at the fuel rail, won't start and run. Perhaps unplug and re-seat MAF connector. Where are you that it is cold now, and is that 0 F or 0 C ? Battery voltage OK? Terminals clean and tight? Including those two in the front of the underhood fuse box? TPS sensor?

 

What weight of motor oil are you using?

 

Mineral oil 10W/30

 

Why mineral oil?
How about fault code numbers, how man miles on it, when was it last tuned along with 8 mm silicone wires, what octane and have you tested your fuel pressure before a cold start?

 

Hello I live in Sweden. I have had the car in approximately the nine years and it is in very good condition. Some bolts to the intake had been tapped up so it was leaking there. I replaced the gasket and made ​​sure everything was tight. Thought this would remedy the problem but it did not help, though it went much smoother after I changed the intake gasket. But cold start problems persisted. I have changed two temperature sensors, but it did not help. If it is at idle and I remove connector amount of air meter will start to go very bad, then it seams to be whole. But when the engine is warm it goes as it should, though I've noticed that if I drive very fast along the road so that passing speed 3000 rpm it starts to chop some perhaps related to cold start problems .... I have used a translation program if you wonder why the text looks weird ....

 

That just means regular motor oil.

 

You need to check the fuel pressure, right side of the engine, towards the front is a schrader valve (tire valve) and using a fuel pressure tester check the fuel pressure.
Put the tester on, then try and start the engine, you need between 30 and 35 pounds per square inch.
Have a friend try to start it as you watch the gauge on the tester.
Also low quality fuel can cause hard cold starts as well as worn out spark plugs and leads.
A old dizzy can cause hard cold starts too.
Also switching to a 5w-40 or 5w-30 motor oil for the winter will help.