Hot Start Problem move from CRD Tech

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Haven't gotten too much input on this problem although many seem to have experienced it.

Fairly happy with my 2006 CRD Liberty. Several months ago it failed to start after an hour of parking. Read this forum and decided to install the new fuel head filter. So far so good until last week. Same scenario, ran to the store, was in about 1/2 hour then failed to start. Started fine when everything cooled down. Read forum again and decided to change out the Crankshaft sensor theorizing that the exhaust is heating up the sensor while sitting, At the same time I had the shop wrap the pipe in fiberglass exhaust tape to help insulate heat from the sensor. We'll see if this fixes the problem.

Maybe one of the experts here can list the most common causes of no starting?

msilbernagel · **Posted:** Sat Oct 06, 2012 10:30 pm

Most common issues seem to be air in fuel, crankshaft sensor, camshaft sensor.

Mark

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Update

New crank sensor and camshaft sensor along with the new fuel head.
Went about three Weeks without a problem then today went to the store, was in for about 15 min came out and she won't start. What's next??

As usual the car started about an hour later (the air temp was about 80). I thinking interlock/ECU because it acts like it wants to start when you first crank it over but never seems to catch (fuel solenoid ?). It has a lift pump and that's working just not sure why you have to wait til things cool off for it to start. Once it starts I can drive hundreds of miles without a problem but shut it down and come back before an hour it it just cranks.

So anyone know what else in the system can cause it to act the way it does?

Thanks guys!

Billwill · **Posted:** Sun Oct 07, 2012 4:37 am

Bear in mind the 2006 CRDs have a known problem with the main wire harness fraying on the fuel filter mounting bracket.
This "should" not be heat related but remove the fuel filter bracket and have a good look at the harness in that area for any fraying.

papaindigo · **Posted:** Sun Oct 07, 2012 7:42 am

Other known no start conditions, shouldn't be heat related, are the ignition switch (box on left side of steering column that "tells" the ECU it's ok to engage the starter and fire up the engine) and the "pin" from the ignition key that turns on the ignition switch (pin can break for partially break so failure is intermittent). There are inexpensive aftermarket solutions for both.

Also could be heat related battery problems if you have an older battery.

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

New battery. When I installed the new fuel head the harness seems to be fine.
Definitely seems to be heat related so kinda doubt the ignition switch. When cranking is seems to start then just doesn't seem to get enough fuel which is why I'm thinking it's somehow related to a signal (ECU, sensor or relay) that isn't giving or getting the go ahead to keep running. It happened twice yesterday and it was about an hour each time before it would start again.

Thanks for the input, will keep the forum posted!

papaindigo · **Posted:** Sun Oct 07, 2012 10:57 am

I seem to recall that there is a fuel pressure solenoid or some such that's related to the fuel return line. IIRC that solenoid is supposed to hold something shut so the fuel rail can build operating pressure. If it doesn't the engine cannot start. Possibly heat related solenoid failure.

Your comment that it seems to want to start but doesn't makes me wonder about fuel delivery to the cylinders. Look at base of injectors for lots of crud which would indicate leaky injector(s) (fix with new crush washers and "O" rings). Also worth double checking primer pump pressure at fuel filter head but with a lift pump before the filter that should be ok.

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Good suggestion. Know where the fuel pressure solenoid is located? I checked around the injectors and they don't seem to be leaking (although I do seem to get a whiff of diesel fuel similar to a flooded engine sometimes when this happens (not always)). Since I changed the fuel head out the priming pump is always firm and haven't seen any air in the fuel head when this condition happens. This condition was the original problem I changed the fuel head and cam/crankshaft sensors in the first place. The ignition switch seems to be another likely culprit but that seems to be related to the engine not cranking at all (or has anyone seen otherwise).

Thanks for the great input!

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Just found this extensive thread on what I'm assuming is the same problem:

viewtopic.php?f=5&t=64199

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

So after reading the thread posted above (all 7 pages) seems like I'm not the only one with this issue. One turned out to be the crank sensor which I've already replaced and the other was reported to be two bad injectors? Seems a little weird for a hot intermittent problem but mozzio says it fixed his problem. With that said I'm running a bunch of Kleen diesel cleaner through the engine on my way back to Tucson (250 miles). We'll see!

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Some valuable info from Oregon Fuel Injection:

"Hi John, your member that replaced the 2 injectors was the one on the right track!! Typically it's the return system inside the injectors that intermittently have the problems. They have ball check seats inside and what happens is when the ball lifts, sometimes they move slightly to a "flat spot in the ball or the seat it self is grooved up and they don't seal all the way thus, most of the fuel that they are receiving gets bypassed back to the tank, and the injectors never get enough fuel pressure to "pop" and send fuel to the cylinder.. so after it cools and the metal contracts and the ball moves or seals due to the contraction, the pressure is back & boom she starts and runs.. and at that point the high pressure pump that feeds the injectors fuel is now building enough pressure to overcome the bypass and they stay running. i do suggest that you take it to a competent diesel shop for diagnostics In tucson there is Desert Diesel Fuel Systems LLC, they do have drive in services and their phone # is 520-792-0132 and their address is 2395 N. Fairview ave. Good luck!!

Oregon Fuel Injection. "

Going to the Desert Diesel place and have them check it out.

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Some useful info. May work for diagnosing a bad injector relating to the hot start problem.

TESTING FUEL INJECTORS

NOTE: The fuel pump pressure must be between 0.8 and 1.2 bar (13-17 psi), and engine must be at operating temperature, engine coolant 88°C (190°F).
1. Run engine until operating temperature is obtained.
2. Turn Off the ignition.
3. Disconnect the fuel injector fuel return hose at the return hose tee directly behind the generator, next to the air purge fitting, leaving the return hose to the high pressure injection pump connected to the pump .
4. Block off fuel return line to high pressure injection pump.
5. Connect a hose to the return hose tee and place it in a suitable container.
6. Start the engine and measure the return fuel for 1 minute at idle.

NOTE: If the quantity of fuel is above 100ml. it means one or more of the fuel injectors has a problem.
7. If the measured quantity is above 100ml, disconnect each individual injector and measure the quantity of return fuel into the container.

NOTE: Make sure to block off the fuel return hose at each individual fuel injector before taking a measurement.
8. Replace the fuel injector that has a return rate above 25ml. for one minute at idle
9. If the test does not give a positive result, disconnect the fuel return line at the fuel rail. If fuel is present, replace the fuel rail
10. Perform the fuel system air purge procedure after replacing any components

sidebrake · **Posted:** Wed Oct 10, 2012 11:04 pm

I battled the exact same issue about a year and a half ago. Oddly enough, I also contacted OFI back then and they directed me to check the injectors. They were indeed the source of the problem. I replaced 1 injector and have had zero problems with my CRD since.

Do the injector leak quantity test. Its really easy to do and I'd bet you find your problem. By the way, I skipped the initial test and went straight into testing each one individually.

Good luck!

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Thanks for the input. I'll do the leak check on the injectors. Has anyone replaced the injectors themselves without taking it to the stealership?
From what I've read there is a calibration code on each injector that must be programmed into the ECU. Except for the dealer not sure how many mechanics would have this ability.

Goglio704 · **Posted:** Fri Oct 12, 2012 9:45 am

The injectors do have a code on them. Green Diesel Engineering can change injector codes in the ECU.

papaindigo · **Posted:** Fri Oct 12, 2012 10:08 am

Two types of injector leaks.
1. around the base which is obvious based on goop in that location. Solution - clean area as much as possible; remove injector (may require injector pulling tool); finish cleaning taking care not to drop crud into cylinder; reinstall injector with new "O" ring and crush washer making sure the little steel "foot" plate is still in the head when you reinstall injector retainer.
2. internal. May or may not require injector replacement as they can be rebuilt. If rebuilt as far as I know no codes are changed.

FYI take care on the return line as I understand there is a plastic part that breaks easily.

sidebrake · **Posted:** Fri Oct 12, 2012 10:53 am

Goglio704 wrote:

The injectors do have a code on them. Green Diesel Engineering can change injector codes in the ECU.

This is what I did. I'd been wanting to get an Eco tune, so I replaced the injector myself then sent the new injector code to GDE (along with the other 3) for the reflash. Two birds with one stone! :JEEPIN:

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

That's great info. Did it run ok after you put the new injector in? It may be a while before I can afford the ecotune.

dave90 · **Joined:** Wed Jul 25, 2012 2:42 pm **Posts:** 12

ok i just had the same problem and after fitting new crank sensor ect i did a simple test on the injectors this is what i did .my problem was the engine would not fire when hot it would just turn over and over i got 4 x small clear plastic bottles fitted a small clear tube to the bottom of each then fixed them to a piece of wood in a row .i then hung the wood under the hood fitting each tube to an injector return line this is with a[ hot engine ] i then cranked the engine over a few times and strait away i noticed that one of the bottles was filling with fuel. as soon as it fired up the others began to fill i took the injector and had it re sealed .it has been fine ever since i hope this will help someone out the it did for me.

jtz54 · **Joined:** Tue Apr 03, 2012 11:37 pm **Posts:** 73

Good info. When you said you had the leaky injector re sealed? Do you mean re-built by a dealer or simply put on a new o-ring and copper crush washer?

Hot Start Problem move from CRD Tech

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