Mopar Muscle Association UK

My 2.8 CRD Jeep Wrangler (well it is a Mopar!) has been very hard to start on these icy mornings. New Optima battery spins it over fine, but it cranks and cranks. Usually starts eventually after cycling the glow plugs a few times.

Runs fine once it starts, no smoke or rough running. No warning lamps. Never been a problem before - has started fine in previous winters, with colder temps (pic). Only seems to be a problem if the temp goes below freezing.

Is it possible that I have the last tank of summer blend diesel? I wondered about water in the fuel, but the dash warning light isn't showing. Think I'll change the fuel filter anyway.

Sorry to impose with a tenuous Mopar, but Google hasn't helped.

Could be the injectors are bleeding back.

Can you check the current draw with the glow plugs on? You may have one or two gone down. Does it rin on all cylinders immediately or does it take a few seconds once it fires?

Thanks for the responses chaps.

I'll check the current draw. Once it fires it idles fine immediately, and no smoke from the exhaust. Feels like it's struggling to push the fuel through to the injectors, but once it's there it's fine.

At any temp above freezing, it fires up straightaway as usual, so maybe when the diesel is a bit thicker, it's too much for the old fuel filter, which I confess I've never changed.

Glow plugs would be my first thought, it only takes one to go down and you get hard starting when it's this cold.

I would go for glow plugs too. You can check them in situe if you can access them, remove the wire/rail, and check for continuity on each individual plug.
no continuity, plug no worky.
unfortunately modern vehicles tend to hide them in impossible to get at locations

Hi Adam,as said above injector leaking back, common problem
You need to get a leak down test on the injectors, ie a little bottle on the return of each injector and you will see one fill lots quicker than the others, ive done a few crd grand cherokee like this, never had any glow plug probelms, plus if there is a glow plug problem the glow plug light stays on for few seconds when it starts up
If you dont have a code scanner (which are peanuts on ebay) depending on year you can switch the ignition on/off a preset no of times (you will have to google it) and this will show you the P fault codes where the mileage was.
Also ifs its recents been serviced ive had probelems with the new filters leaking hence drawing air where the pipe pushes into top of them.

Thanks chaps, much appreciated.

Glow plug lamp goes out a few seconds after turning key to ignition, as normal, so maybe it's an injector return. But wouldn't that cause problems in milder temps too? She's started on the button these last few days. I'll see if the OBDII scanner reports anything.

Needs a service anyway. Just ordered and paid for a service kit on Ebay comprising oil, air and fuel filter for £33. Then they email to say they can't do the fuel filter, but they can do the other 2 for £40? Sigh