kj diesel wont start when cold

[Billwill]

Controller is a small unit next to the battery I think.

Early Export KJs, such as my 2002 Export 2.5 CRD, do not have a controller but have 11 volt plugs powered direct to 12 volts via two large relays in fuse box under the bonnet.

I think about late 2003 with the 2.8 engine the Export Crds upgraded to the newer system with 5 volt or 7 volt glow plugs.

Most owners on lostjeeps.com find that 5 volt ceramic plugs work well using a controller programmed for 7 volts.

You can download the Jeep KJ Service Manuals for your year KJ from the link at the top of the stickies ie. at www.colorado4wheel.com/manuals/Jeep/KJ/

[glend]

The Service Manual tells you how to test each glow plug with a multimeter from the connector. And yes it should be next to the battery ( firewall side).
I suggest you try bleeding the fuel head, as trapped air can make them hard to start.

[tassiefsj]

thanks for the info guys .
I'll check it out after xmas

[TOIIIIIIIOJ]

My understanding on the 5volt model glow plugs is that they only glow on engine crank as they super quick heat up, not like the early 12v to where they'll glow first before the crank over.

[baalsjeep]

I have the 2005 kj crd with exactly the same issue with cold starts since i changed out the ceramic plugs, however found that the following improved things, 800CCA Optima 34 battery helped heaps the crd needs a good battery for the glow plugs and starter to work, reprogram the ecu for 5v metal plugs , and as for where the glow plug controller is its just behind the battery and has Bosh 0281 003 034 written on it looks like an oversized relay.



The Jeep 5v metal glowplug swap says that this controller needs to be changed with the change to the 5v plug but it has an identical part number so I am still not sure why as its not what controls the voltage that is done with ecu programming, its not exactly cheap to replace.

cheers

[tassiefsj]

Hi guys ,back again
after lots of testing glow plugs,injectors, etc I have found the the diesel is losing pressure in the system causing a no start
i put a non return valve between the diesel pump and filter housing ,primed it up and it started ,
i tried it over a few days and it was hit and miss wether it would start .
id get it to start ok ,leave it overnight ,sometimes it would start straight away,other times back to no start
so my conclusion is that its a pressure issue
i noticed that someone had put standard (petrol)fuel hose between the pump and filter housing ,maybe that is the issue, (not being high pressure hose)
Ill replace that and then my next move is to remove the diesel pump and check it out .
any tips,thoughts,clues would be appreciated before I start tearing it apart
this is not our daily drive, but will be if i can get it sorted out
cheers

[Billwill]

On Lostjeeps and jeepkj.com the advice is to fit 5 volt plugs with a 7 volt controller.

My 2002 Export 2.5 CRD has 11 volt glowplugs powered by two big relays with 12 volts...one volt is lost over the relay contacts and other connectors. This is completely different to the newer systems but here in South Africa in the middle of winter I have disconnected the glowplugs and can start it up no problem!

Lots of smoke and rough running for a while but it starts OK.

Just makes me wonder if you have a problem elsewhere.
The Cam Sensor and the Crank Sensor are known to fail sometimes when hot but I have never heard of them failing when cold!
Probably getting air in fuel somewhere, have you checked for fuel leaks at all the fittings?

The 2005 CRD has a Front Control Module (FCM) mounted near the battery. It has one connector on it that can get gunged up with water, mud etc.
Worth cleaning that connector up.
The FCM basically directs all the various busses, PCI, CAN, SCSI etc. all over the place and I see on the other sites that it can cause all sorts of weird problems!