Bugout4x4

OK dug around this morning and it raised yet another question. Are you getting smoke from the exhaust when you first try to crank it? And if so what color is it? White, blue, black?

Mipar28

No smoke, on cranking, little bit of white smoke once it starts.

Bugout4x4

Ah! now I finally asked the right question! I am almost sure you have a fuel delivery problem then. It might be sucking air somewhere and draining back towards the tank or a primary pump. This is a huge indicator that it is not getting enough fuel when you are trying to start it. It should smoke as soon as it starts to turn over and the whole time you are cranking it until it fires.

There is light at the end of the tunnel! lol

Now let me go find schematics of the fuel delivery system for possibilities.

We will lick this yet.

Tbone289

Bugout normally gives sound advice, but I don't recommend you lick it.

Bugout4x4

I agree! I stand corrected, I may have misguided him a bit there... lol

Bugout4x4

I am still trying to find a complete fuel system schematic on this. But here are a few things to address but keep in mind I am still in the dark with this system and what exact components it has.

Did this first start to have problems after anything on the fuel system was replaced or serviced?

But here is a list of possibles and I am curious if you have already played with any of them?

Does it have a primary fuel pump? I'm trying to chase this down just to be sure, it should have... But once the fuel is primed up to the pump and injectors a diesel will run fine without the primary pump. So it could just be a Primary pump problem.

I did see this is a common rail system... So it more than likely has a pressure management valve and a return line? This could be bad and not maintaining pressure and fuel. Checking into this also.

And finally, when was the last time the filter (or filters?) has/have been serviced? I apologize for the delays but like you... I am also having a heck of a time finding what I need with this model and system but I ain't giving up yet.

Mipar28

I’ll give you a bit more background, the problem first manifested itself last winter, we persevered, because it only didn’t start when the temperature dropped below freezing, all this summer it was fine, when we had it serviced in the summer we had the crankshaft sensor changed, it started as soon as it was cranked, right up until last week, when the temperature dropped below freezing. I gave it a squirt of starter fluid, and it fired up straight away. The problem seems to only rear it’s head when the temperature drops below freezing. As soon the weather improves it’s back to starting straight away. Baffled

Bugout4x4

Actually this is kind of normal for diesels because of the "cloud point" of diesel fuel. The cloud point and thickening starts at +1 degree Celsius and slows the flow through filters and any restrictive porting in the system like injectors, getting worse the colder it gets until it finally gels solid at -8.1 degrees Celsius. When it gets down to freezing sometimes you have to start using winter fuel to help with this.

But things get even much worse if you have restricted filters or water in the filters or for some reason a weak delivery system. Which is what I suspect on yours. I would go have the filter or filters changed on this thing. It is very easy to get diesel with water in it or even fuel with algae in it. Both of which will clog filters.

At any rate, the lack of any smoke when you first try to start it tells me you are not getting fuel for some reason. Then right after you get a little smoke it fires up? That was when the fuel pressure finally got to the injectors for it to start. if it were mine I would get these fuel filter/filters serviced and then see if there are any further problems and go from there.

Actually I would do this at least just before winter every year just for peace of mind knowing that colder temps are coming.

Edit: Sorry I reread your reply. you did have it serviced. But could there be more than one filter and they changed the secondary but didn't change the primary in the system? (this is a very common goof up).The next issue that could cause this of course is a pump. If you can afford it I would go have the integrity of the fuel delivery system tested or download a manual at one of those online sources and test it yourself. We are down to that point with this. I would have to come physically look at the system and test it to be of much more help here. It's hands on time on your end but I am almost 100% sure it is a fuel delivery issue. Be sure and tell them that "it is slow to get fuel during cold starts". This is important because once it is started and running everything might check out fine when they check it. They need to know about this so they can look for additional problems.

BillyBoy

New battery. See if it starts with a jump. When cold. Takes more amps.

Bugout4x4

Were you able to figure this out? I am hoping you didn't have to give up on it.

Awt34

Hi
just wondered if this issue was resolved as my 2002 Cherokee has started exactly the same issue?
I have put on
new battery
new heater plugs
a none return fuel valve
new fuel filters

always starts with jump leads but randomly won’t start but will crank over until it flattens the battery!!

I have now purchased a crank sensor and cam sensor to try and a new starter motor ( hope to fit all 3 this week) but very much working in the dark?

once it’s started it runs and restarts just fine but does kick out a small amount of black smoke when changing gear or accelerating( but it is a 2002 on 126K miles)

TIA

Veeb0rg

Hi, Welcome to the forums.

Please create a new thread not bumping an 7yr old one.

Also your Jeep is a KJ not an XJ. You'll have better luck asking for help in the Liberty / KJ section.