kj diesel wont start when cold

[glend]

If your having problems starting, but it runs fine after you get it going, I would check the fuel head for leaks before tearing into the pump. What happens if you bleed either on the fuel head? Does it hold vacuum or drops away? It may be something extremely easy to fix. Don't look for complexity first.

[Jonny Jeep]

Somebody in the UK had problems with a WJ not starting when cold recently. For them the fuel lines at the engine were the problem, and fitting new mopar fuel lines fixed it.

[glend]

Yeah, well KJ CRDs are known for fuel head air leaks, start there.

[tassiefsj]

Originally Posted by glend

Yeah, well KJ CRDs are known for fuel head air leaks, start there.

thanks Glend
i assume you mean the pipework to the injectors or am i missing something .

[baalsjeep]

Originally Posted by tassiefsj

thanks Glend
i assume you mean the pipework to the injectors or am i missing something .

no they are talking about the fuel head that big black unit on the firewall with the heater and the fuel filter and the primer hand pump, its known to be a source of air leaks .

I would consider a compression test too, low compression can cause hard starts when cold, check to see if when started there is much blowby from the oil filling cap.

I have a 05 jeep with the same issue 5v glow plugs, and have a can of aerostart for them cold mornings, when its not firing up.

keep us up to date on what you find.

[tassiefsj]

Originally Posted by baalsjeep

no they are talking about the fuel head that big black unit on the firewall with the heater and the fuel filter and the primer hand pump, its known to be a source of air leaks .

I would consider a compression test too, low compression can cause hard starts when cold, check to see if when started there is much blowby from the oil filling cap.

I have a 05 jeep with the same issue 5v glow plugs, and have a can of aerostart for them cold mornings, when its not firing up.

keep us up to date on what you find.

thanks mate ,the previous owner replaced that before I got the jeep,
he also replaced the glow plugs and injectors ,installed an inline pump in the fuel line in the chassis ,
it starts with earostart but if you turn it off and restart it will fire up ok but leave it for 10 mins and it takes a bit longer to fire and so on .

but funnily enough ,SOMETIMES if you leave it overnight it will start straight up the next morning its a bit hit and miss .
i put a non-return valve between the filter and the diesel pump which improved it a bit for a while but still has the issue
Ill recheck the fuel head for leaks and your other suggestions and let you know the outcome ,
thanks for the advice

[layback40]

Originally Posted by tassiefsj

thanks mate ,the previous owner replaced that before I got the jeep,
he also replaced the glow plugs and injectors ,installed an inline pump in the fuel line in the chassis ,
it starts with earostart but if you turn it off and restart it will fire up ok but leave it for 10 mins and it takes a bit longer to fire and so on .

but funnily enough ,SOMETIMES if you leave it overnight it will start straight up the next morning its a bit hit and miss .
i put a non-return valve between the filter and the diesel pump which improved it a bit for a while but still has the issue
Ill recheck the fuel head for leaks and your other suggestions and let you know the outcome ,
thanks for the advice

When its cold from an overnight stop, try pumping the primer, if it takes more than a couple of pumps to go hard, you have an air leak.