Timing belt?

805gregg · **Posted:** Wed Oct 06, 2010 7:49 pm

I started my Jeep yesterday, put it in reverse and it died, I immediately thought the timing bet broke. No codes show. Is there a simple way of telling if the belt broke? I have 94,000 miles so I have been thinking of the belt in a few thousand miles. Help please.

CATCRD · **Posted:** Wed Oct 06, 2010 9:41 pm

Have you started it since then? Try bleeding the air bubbles from the filter head and I bet it starts right up. When was the last time you changed the fuel filter? The increased fuel demand when you drop it in gear can be enough to starve it if you have a dirty fuel filter.

flman · **Posted:** Wed Oct 06, 2010 9:45 pm

Could be a transmission problem? Did you try to restart it?

geordi · **Posted:** Thu Oct 07, 2010 12:24 am

Did it make any noises when it stopped, or did it just cut out? If it didn't make any "BANG tinkle tinkle tinkle" kind of sounds... You don't have a broken timing belt.

If the timing belt broke, the timing would jump and the pistons would slam into the valves and break every rocker arm. This is the designed failure mode, and it would NOT be pretty or quiet.

I'm in agreement - Fuel issue is the most likely cause. Try changing the fuel filter (and refill it with clean diesel before installing it) and give it another go.

flman · **Posted:** Thu Oct 07, 2010 6:38 am

viewtopic.php?f=5&t=53321

viewtopic.php?f=5&t=55072

805gregg · **Posted:** Thu Oct 07, 2010 10:23 pm

It turns over just fine but doesn't start, the fuel filter is 2 months old. I'll check that tomorrow. Thanks.

805gregg · **Posted:** Sat Oct 09, 2010 11:02 am

How would I get air bubbles out if I find some?

CATCRD · **Posted:** Sat Oct 09, 2010 11:35 am

Pump the plunger on the fuel head until it firms up (don't go overboard pumping) then use an 11mm wrench to loosen the bleeder screw on the opposite side. Use a rag to catch any fuel that dribbles out. Tighten the screw and repeat until you don't get air the next time.

flman · **Posted:** Sat Oct 09, 2010 12:02 pm

805gregg wrote:

It turns over just fine but doesn't start, the fuel filter is 2 months old. I'll check that tomorrow. Thanks.

Thanks for the real time info, any DTCs?

805gregg · **Posted:** Sat Oct 09, 2010 3:46 pm

CATCRD wrote:

Have you started it since then? Try bleeding the air bubbles from the filter head and I bet it starts right up. When was the last time you changed the fuel filter? The increased fuel demand when you drop it in gear can be enough to starve it if you have a dirty fuel filter.

Bingo, Thanks, air in the fuel, bled it and now is fine, but I've driven this diesel for 94,000 without this happening. How does the air get in the fuel filter?

CATCRD · **Posted:** Sat Oct 09, 2010 3:54 pm

Pull the heater plug out from the fuel filter head (the plug on the right) and see if it's wet with fuel. If so, that's where your air is leaking in. Is the rim of your fuel filter wet with fuel? Try tightening the filter a little more, especially since you changed it recently. Or maybe a lift pump is in your future.

805gregg · **Posted:** Sat Oct 09, 2010 9:35 pm

CATCRD wrote:

Pull the heater plug out from the fuel filter head (the plug on the right) and see if it's wet with fuel. If so, that's where your air is leaking in. Is the rim of your fuel filter wet with fuel? Try tightening the filter a little more, especially since you changed it recently. Or maybe a lift pump is in your future.

I'll check that tomorrow, I hope it's not the lift pump, that sounds expensive. Thanks again, now I carry an 11 mm wrench with me.

CATCRD · **Posted:** Sat Oct 09, 2010 9:43 pm

Your Jeep didn't come with a lift pump. But adding one isn't expensive. $50 - $150 depending on your choice. People add them to cure just the problem you're experiencing.

warp2diesel · **Posted:** Sat Oct 09, 2010 9:43 pm

805gregg wrote:

It turns over just fine but doesn't start, the fuel filter is 2 months old. I'll check that tomorrow. Thanks.

I haven broken a timing belt on a CRD, but on VW diesels the engine does not have the normal pulsing sound from compression. Also you hear the metallic sound of the pistons crashing into the bent valves.
X2 on the air bubbles in the fuel system.

X2 on the lift pump too.

papaindigo · **Posted:** Sun Oct 10, 2010 9:50 am

Even if you go with a lift pump, I have not, at minimum you need to be sure you have the upgraded fuel filter head. See info at http://www.greendieselengineering.com/f ... st/76.page. The original head, as noted, tends to leak where the heater plugs in and even if it doesn't the heater element is too small for the current and can easily short with bad results. In my opinion there are only 2 kinds of original fuel filter heads 1) those that are leaking and 2) those that will leak. Given that new head comes with a new filter the real cost of replacement is like $55. Installing a lift pump as an assist to the stock pump can help and I may add one someday but it you have a leak adding pressure behind the leak may cure the air problem but at the cost of making the leak a bit worse.

When you change the fuel filter of course you need to prime the system but it's also a good idea to reprime/bleed the system after you have run through about a tank of fuel to release any air caught in the lines while changing the filter.

geordi · **Posted:** Sun Oct 10, 2010 12:12 pm

A couple of points I have to counter:

I have the original fuel head design. (Two of them, actually, got one with the replacement engine) It does not leak, and it is not going to leak if it hasn't already - I'm closing on 100k rapidly.

With a lift pump installed in or near the tank, my fuel heater coil (when I choose to have it plugged in during the winter) is being constantly bathed in fuel because the pump pushes fuel to the top of the head - Forcing any air back to the tank and out of the lines. That is why I am not concerned about either the head leaking or the heater cracking - It cracks because it overheats by NOT being in fuel constantly, and because they built the head from plastic.

The "stock pump" you mention is ONLY the injection pump on the engine. Yes, this is a suction pump that is pulling fuel all the way from the tank and through the filter (and filter head) to the engine. I'm making a distinction about this not to say that it isn't a fuel pump, but so that people avoid confusion about the following:

If you do not have a LIFT PUMP that is PUSHING fuel from the tank TOWARD the filter (And you chose to install this yourself since NONE came from the factory with this) then you have a SUCTION fuel system, and air bubbles will be pulled out of the fuel and collect in the fuel head.

Having a lift pump pushing fuel to the filter and engine pump means that you now have a low-pressure system - Air will not collect in the filter head ever, certainly not enough to cause any air-in-fuel engine problems (Which can AND HAVE lead to injection pump starvation and failure). You do not EVER need to use the priming button again, even when changing the fuel filter. Your process becomes: Change filter, turn key on (do not start) and listen to a cool song on the radio. By the time the song is over, the filter is full of fresh fuel from the tank, the air has been pushed through the system back to the tank, and the CRD is ready to go back to work.

Much easier.

Joe Romas · **Posted:** Wed Oct 13, 2010 8:02 pm

geordi

X2

manuel754 · **Joined:** Wed Jul 14, 2010 9:15 pm **Posts:** 35

whole nuther question >>>>>>>
does the lift pump increase performance?

geordi · **Posted:** Thu Oct 14, 2010 12:21 am

It can, in two ways:

Your filter can last longer, because it is easier to push fuel through a restricted filter, than it is to suck fuel from the other side. In a suction system, the negative pressure will cause the filter material to actually compress as the debris is unable to be sucked through. This closes the pores in the material, blocking more fuel, causing more negative pressure and compression of the filter material... Until the engine stalls from fuel starvation.

By having a positive pressure behind the filter, it will act to equalize the pressure on both sides of the filter material, so when it finally DOES clog - It is well and truly done.

The second method of performance increase is in times of high demand and low RPM. A constant positive supply of fuel relieves pressure off the injection pump and reduces the possibility that the lubricating gallery in the pump (filled with incoming fuel from the suction demand) ever gets less than totally full. The high pressure side takes its supply from the lubricating gallery, not unlike a carburetor bowl supplies the jets. If the bowl empties - No go. But in this case, at a low RPM, the suction pump (in a purely stock system) is not pulling the same volume as at a high RPM... Yet this is when the engine is usually working the hardest (towing, accelerating from a light), so if the demand exceeds the supply... Fuel starvation and possible pump damage.

A lift pump ensures that whenever your engine asks for a bigger drink, the "river" through the pump is nice and full without waiting.

OldSkull · **Posted:** Fri Oct 15, 2010 12:55 pm

805gregg wrote:

now I carry an 11 mm wrench with me.

May I suggest you this little mod to make your life sooooo much easy! :mrgreen:

http://www.lubricationspecialist.com/front/shop.aspx?catid=16&parentid=0

Timing belt?

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