CRD Not Starting When Hot

[tundraboar]

We have a 2005 KJ with the CRD engine. For some time now, we've had problems with it starting when the engine is hot ... or if we've parked in the sun in the summer (or winter sometimes). This has been going on for over a year and seems to be getting worse. We've talked to a number of mechanics (including dealers) and they simply shrug their shoulders and ask to have it brought in so they can check it out. (Nothing like sucking $$ out of you.)

After the engine has been run a while and gets hot, if you shut it down, many times (not always), when you try to start it, it will simply turn over for as long has you hold the key in the start position ... and nothing happens other than draining the battery. Then, let it sit for anywhere from 10 minutes to several hours, and try it again and it starts right up ... within 2-3 seconds of trying. I've put a meter on it and it is throwing no codes.

It should also be noted that, when started and running, it shows no signs of any problems and will run for hours ... no problems even in situations where you're 'pedal-to-the-metal'.

Based on what we've experienced, it seems to be something related to the fuel delivery. If it were a filter problem, I would expect it would show up somehow when running, but it doesn't. I've heard that there could be a problem with electrical delivery to the fuel pump. I've also heard that there is a valve in that fuel delivery line that must be opened and that could be a problem.

We did hear that the fuel system could start pulling a vaccum if it's sealed up too tight. This can be checked by simply removing the fuel cap and starting it. Tried ... no luck ... still didn't start.

I'd love some ideas on what to consider. Also, if anyone has any recommendations on a GOOD repair manual for this rig, I'd really appreciate that.

 

[Billwill]

Does your Jeep have a fuel pump installed? They do not come from the factory with a fuel pump installed but most of the wiring harness is in place. You should be able to hear it running.

My 2002 Export CRD does not have a fuel pump and I have never had problems in that area.

The fuel-line fittings can leak.

When you have this problem do the procedure at the fuel filter head to pump out any possible air in the system and make sure you have a clean fuel filter....the Export CRDs such as mine have a different Fuel Filter Head to the USA models so you need to read up on the procedure.

The Jeep KJ Service Manuals can be downloaded here: www.colorado4wheel.com/manuals/Jeep/KJ/

 

[tundraboar]

Does your Jeep have a fuel pump installed? They do not come from the factory with a fuel pump installed but most of the wiring harness is in place. You should be able to hear it running.

My 2002 Export CRD does not have a fuel pump and I have never had problems in that area.

The fuel-line fittings can leak.

When you have this problem do the procedure at the fuel filter head to pump out any possible air in the system and make sure you have a clean fuel filter....the Export CRDs such as mine have a different Fuel Filter Head to the USA models so you need to read up on the procedure.

The Jeep KJ Service Manuals can be downloaded here: www.colorado4wheel.com/manuals/Jeep/KJ/

Thank you! I'll check this out and let you know.

 

[CFarrar]

It's likely to be the engine's crankshaft position sensor. It's mounted on the passenger side of the engine toward the back and is near the exhaust pipe. Heat degrades them over time and they start to misbehave intermittently. Reading I've done suggests that at its age it's a good idea to replace the original, whether it's acting up or not.

There is no fuel pump. It relies upon vacuum to suck fuel from the tank unless someone has modified the fuel system. Chrysler decided to save money on this model, but equipped their diesel pickups of the same vintage with in-tank fuel pumps. A common problem is deterioration of sealing systems at connections resulting in leaks that allow air to be sucked into the line. The fuel tank sending unit used in the pickups fits the Liberty CRD tank and can be installed after the addition of two wires to the wiring to run the fuel pump.

 

[tundraboar]

Thank you! I'll check this out and let you know.

Didn't work. Thanks anyhow.

 

[tundraboar]

My last post was for Billwill.

CFarrar: That sounds interesting also. My latest 'investigation' indicates that it is simply engine heat that is causing the problem. Two days ago it was cooler ... and it started up no problem at any time. Today, after running a while this morning, I parked in the sun. When I went back 10-minutes later and tried to start it, no problem ... started right up. However, 20-minutes after that, it would NOT start. It's now 2-hours later and I've tried twice to start it ... nothing. Simply turns over. Temp outside today is 90+. Two days ago, it was low-mid 70's.

Hmmm ... going to have to check that out!

 

[tundraboar]

It's likely to be the engine's crankshaft position sensor. It's mounted on the passenger side of the engine toward the back and is near the exhaust pipe. Heat degrades them over time and they start to misbehave intermittently. Reading I've done suggests that at its age it's a good idea to replace the original, whether it's acting up or not.

There is no fuel pump. It relies upon vacuum to suck fuel from the tank unless someone has modified the fuel system. Chrysler decided to save money on this model, but equipped their diesel pickups of the same vintage with in-tank fuel pumps. A common problem is deterioration of sealing systems at connections resulting in leaks that allow air to be sucked into the line. The fuel tank sending unit used in the pickups fits the Liberty CRD tank and can be installed after the addition of two wires to the wiring to run the fuel pump.

My bad ... I responded to you but didn't hit the reply button earlier. So it's down below.

I do have another related question: Why would the position sensor not work when hot, but after cooling down, does just fine?

Another related thought though ... it runs fine at all speeds when running. However when running (driving), there's plenty of air flow around the engine to keep it cool. (When sitting still with the engine running, it can just keep going ... maybe.) Sitting still, engine NOT running, heat (either from the engine block or the sun) could cause it to get hotter, crossing that line of working vs not working.

In my 'test' this morning, ran it for a while (30-45 min), got back, parked in the sun shut it down. Went back out 10-minutes later, it started just fine. 20 minutes after that, I tried and nothing ... wouldn't start. Temperature was up to mid-90's today. Two days ago with a similar test, air temp stayed in the mid-70's.

I'll try to keep you posted, but this is the BEST information I've gotten yet!

 

[Michael Noland]

I had a bit different problem with my 2005 CRD. It would stall and go into limp home mode. I could turn it off and sit a minute, and it would start and run normally. Turns out the fuel filter housing leaked. I think there was a service bulletin about that. Once I replaced the housing, I never had another problem. My granddaughter is driving it now.

You might want to try replacing the housing. On our heavy equipment, we would look for leaks in the air intake system by spraying starting fliud around the filter. RPM would go up if you had a leak. You might want to try that around your housing.

 

[Billwill]

Just to clear up a few things:

The CRDs did not come out from the factory with a fuel pump but the harness was fitted in place just short of the fuel tank.

Many CRD owners have fitted Fuel Pumps to their Jeeps to resolve issues...there are various makes of pumps available....post a request here for advise on what pump to get if you decide to go that way.

I meant to suggest replacing the Crank Sensor....a very common problem with the CRDs that fail to start when hot...make sure it is located properly in place before tightening it up....I would go for this first before looking into fitting an electrical fuel pump!

 

[tundraboar]

I had a bit different problem with my 2005 CRD. It would stall and go into limp home mode. I could turn it off and sit a minute, and it would start and run normally. Turns out the fuel filter housing leaked. I think there was a service bulletin about that. Once I replaced the housing, I never had another problem. My granddaughter is driving it now.

You might want to try replacing the housing. On our heavy equipment, we would look for leaks in the air intake system by spraying starting fliud around the filter. RPM would go up if you had a leak. You might want to try that around your housing.

My mechanic is working on the fuel filter now. I'll check with him.

 

[tundraboar]

Just to clear up a few things:

The CRDs did not come out from the factory with a fuel pump but the harness was fitted in place just short of the fuel tank.

Many CRD owners have fitted Fuel Pumps to their Jeeps to resolve issues...there are various makes of pumps available....post a request here for advise on what pump to get if you decide to go that way.

I meant to suggest replacing the Crank Sensor....a very common problem with the CRDs that fail to start when hot...make sure it is located properly in place before tightening it up....I would go for this first before looking into fitting an electrical fuel pump!

That sounds like the problem. My mechanic is working on the fuel filter right now, but we have already discussed changing out that position sensor. Great suggestion ... THANK YOU!

 

[tundraboar]

I had a bit different problem with my 2005 CRD. It would stall and go into limp home mode. I could turn it off and sit a minute, and it would start and run normally. Turns out the fuel filter housing leaked. I think there was a service bulletin about that. Once I replaced the housing, I never had another problem. My granddaughter is driving it now.

You might want to try replacing the housing. On our heavy equipment, we would look for leaks in the air intake system by spraying starting fliud around the filter. RPM would go up if you had a leak. You might want to try that around your housing.

My mechanic is working on the fuel filter now. I'll discuss it with him. Thank you!

 

[tundraboar]

Just to clear up a few things:

The CRDs did not come out from the factory with a fuel pump but the harness was fitted in place just short of the fuel tank.

Many CRD owners have fitted Fuel Pumps to their Jeeps to resolve issues...there are various makes of pumps available....post a request here for advise on what pump to get if you decide to go that way.

I meant to suggest replacing the Crank Sensor....a very common problem with the CRDs that fail to start when hot...make sure it is located properly in place before tightening it up....I would go for this first before looking into fitting an electrical fuel pump!

Great suggestions. I'm not going to go down the fuel pump road yet. And we'll probably go for the position sensor next ... maybe next week. Thank you!

 

[tundraboar]

My bad ... I responded to you but didn't hit the reply button earlier. So it's down below.

I do have another related question: Why would the position sensor not work when hot, but after cooling down, does just fine?

Another related thought though ... it runs fine at all speeds when running. However when running (driving), there's plenty of air flow around the engine to keep it cool. (When sitting still with the engine running, it can just keep going ... maybe.) Sitting still, engine NOT running, heat (either from the engine block or the sun) could cause it to get hotter, crossing that line of working vs not working.

In my 'test' this morning, ran it for a while (30-45 min), got back, parked in the sun shut it down. Went back out 10-minutes later, it started just fine. 20 minutes after that, I tried and nothing ... wouldn't start. Temperature was up to mid-90's today. Two days ago with a similar test, air temp stayed in the mid-70's.

I'll try to keep you posted, but this is the BEST information I've gotten yet!

Finally getting back to you on this. Got the crank shaft position sensor changed and have been driving the car now for about 2 weeks with no problems. Hooray!!! While the hot weather seemed to be involved and we have not had any hot weather since we got the rig back, it looks like this did the trick! Thanks for your help.