CRD Misfire

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

Help! My wife's 2006 CRD (~81k miles) started running rough today and had no power. I met her at the side of the road and brought my code reader with me. It's throwing a P0304, cylinder misfire on #4. The service manual recommends:

Quote:

Diagnostic Test 1. CHECK FOR ACTIVE DTC
NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC. With the scan tool, erase ECM DTCs. Test drive the vehicle and attempt to duplicate the problem.
With the scan tool, read ECM DTC’s.
Did this DTC set again? Yes >> Go To 2
No >> Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. FUEL CONTAMINATION
Refer to the Service Information and inspect the fuel supply for contamination.
Is the fuel contaminated?
Yes >> Refer to the Service Information to remove and replace fuel throughout the fuel system. Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No >> Go To 3

3. ENGINE COMPRESSION
Turn the ignition off. With the scan tool, perform the Cylinder Compression Test.
Is the cylinder compression within specification for all cylinders?
Yes >> Go To 4
No >> Repair as necessary in accordance with the Service Information. Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

4. FUEL INJECTOR QUANTITY
Turn the ignition off. With the scan tool, perform the Injector Quantity Test.
Is the Injector Quantity within specification for all cylinders?
Yes >> Go To 5 No >> Repair or replace as necessary in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

5. FUEL INJECTOR LEAKAGE
Turn the ignition off. Perform the INJECTOR LEAKAGE TEST in accordance with the Service Information.
Were any problems found?
Yes >> Repair or replace as necessary in accordance with the Service Information. Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No >> Test Complete.

Of course I don't have the dealer scan tool. I have a Innova 3150 and an older Elm-Scan unit. Any notion on how I might perform these tests without the magic dealer tool? Suggestions on other things I might try? I'm tempted to pull the injector, though the service manual makes it look like a big hairy deal.

racertracer · **Posted:** Tue Sep 13, 2011 7:57 pm

When was the last time you changed your fuel filter? How many miles ago?

warp2diesel · **Posted:** Tue Sep 13, 2011 8:38 pm

Check for air in the fuel yet?

CATCRD · **Posted:** Tue Sep 13, 2011 10:00 pm

Does it idle? If it idles rough, unplug one fuel injector at a time. If the idle changes, that injector was working, so plug it back in and go to the next. Whichever one does not change the idle when unplugged is malfunctioning.

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

It idles incredibly rough. Clearly one of the cylinders is unhappy.

w/r/t air in the fuel system, I have no reason to believe there is, but I haven't checked.
w/r/t the fuel filter, it's a little overdue. Last time I did it was around 55k. My lovely wife picked up the filter two weeks back, I just hadn't gotten to it.

I can change the filter and bleed the system, but I'm a bit at a loss w/r/t why one injector/cylinder would be unhappy and the others would remain okay. There's just a single fuel rail, wouldn't an air or filter issue impact all of them? Or am I confused?

BTW, I did read the noob faq -- very helpful. I bought my CRD new and have done all of the basic maintenance on it myself. I bought the service manual too, and have found it to be almost useless on anything of importance. I didn't even realize I had a MAP sensor, much less that it might need cleaning. Sigh.

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

So, here's what I can tell you:

I checked if there was air in the fuel system. There was a little. I bled it. (Candidly this one continues to mystify me: I bleed it. I get it so that I just get solid fuel. I check it a few days/weeks later, and there's air. I first noticed this after my first fuel filter change, because there was a "buzzing" noise that began only after the fuel filter change and seems directly related to air in the system.)

I also pulled the wire off each injector in turn. Forgive me for being a silly noob, but I would think that the injectors would be 1-2-3-4 front to back, or 4-3-2-1 front to back. Is this not so? Basically what I found was this: if I unplugged any of the injectors *except* the second one in from the front (which I guess is in fact #4, if my code reader is correct?), the engine won't run. It turns over a few revolutions and dies. If I unplug the second one in, it actually runs *better*. It still runs very poorly, but there is less knocking and gyrating by the engine. There's also a high pitched noise that seems directly related to that injector. Unplugged == no high-pitched screechy noise with an engine that's unhappy, but otherwise okay. Plugged in and there's this periodic noise, and the engine seems like it's doing violence to itself. All of this makes me very worried.

Thoughts? Is it worth switching injectors between cylinders?

What is the cylinder order anyway?

Ajamant · **Posted:** Wed Sep 14, 2011 12:06 am

You need to rule out one problem at a time. I'm gonna guess you have not upgraded to the proper fuel head with an upgraded plug for the fuel heater to prevent major air leaks and lots of problems.

Search info on upgraded fuel head and you will find plenty of info. If there is no splicing of the wires into the plug on the drivers side of fuel head, then you have the old fuel head and need to upgrade. This is an easy fix and should be done before you start replacing injectors.

Someone please correct me if I'm wrong but the spark plug order is from front to back 1-2-3-4, so I'll assume the injectors follow the same order (assume???)

WolverineFW · **Posted:** Wed Sep 14, 2011 12:23 am

Ajamant wrote:

You need to rule out one problem at a time. I'm gonna guess you have not upgraded to the proper fuel head with an upgraded plug for the fuel heater to prevent major air leaks and lots of problems.

Search info on upgraded fuel head and you will find plenty of info. If there is no splicing of the wires into the plug on the drivers side of fuel head, then you have the old fuel head and need to upgrade. This is an easy fix and should be done before you start replacing injectors.

Someone please correct me if I'm wrong but the spark plug order is from front to back 1-2-3-4, so I'll assume the injectors follow the same order (assume???)

You have spark plugs in yours? :wink:

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

Bleeding it didn't make a difference. I can put a new filter on the existing head, or I can order a new head wait for a few days and do the head and the filter at the same time, or I can see if the dealer has one and pay full freight, but have it tomorrow. Any recommendations?

As much as I'd love for this to just be an air issue, it doesn't sound that way, and I really don't understand why it would only affect one injector. Is there something I'm misunderstanding?

racertracer · **Posted:** Wed Sep 14, 2011 1:00 am

Keith from GDE should be back from vacation soon he may help.

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

One other thing: In addition to the P0304, I'm also getting a P0101, P0700, and P0725. I'm assuming the P0725 is because the engine isn't running properly.

Sir Sam · **Posted:** Wed Sep 14, 2011 1:46 am

Ajamant wrote:

You need to rule out one problem at a time. I'm gonna guess you have not upgraded to the proper fuel head with an upgraded plug for the fuel heater to prevent major air leaks and lots of problems.

Search info on upgraded fuel head and you will find plenty of info. If there is no splicing of the wires into the plug on the drivers side of fuel head, then you have the old fuel head and need to upgrade. This is an easy fix and should be done before you start replacing injectors.

While I won't disagree that the newer fuel head is better, if his heater plug is dry and unburnt looking and he can bleed the fuel head I think its reasonable to say its not the problem(though a dirty fuel filter might still be causing issues).

I for example have no problems with my original heater heads, and haven't felt the need to upgrade yet, so the heater head isn't necessarily a problem.

racertracer · **Posted:** Wed Sep 14, 2011 1:57 am

P0304 - Cylinder 4 Four Misfire Detected

P0101 - Mass Air Flow (MAF) Circuit Range/ Performance Problem.

P0700 = Transmission Control System Malfunction Diagnostic Trouble Codes (DTC)

P0725 = Engine Speed Sensor.

Joe Romas · **Posted:** Wed Sep 14, 2011 6:51 am

So now you know there's a MAP and that it needs cleaned. Have you cleaned it yet?
I also have my original fuel head and no leaks. I strongly suspect the filter head problem was a direct result of excess air in the fuel :dizzy:

Correct the air in the fuel problem and the fuel head won't overheat :2cents:

Since yours is a 06 check the cable that runs behind the fuel filter bracket for bear wires and or chaffing.
This only seems to be a problem on the 06 because they apparently raised the filter head to clear the ABS/ESP pump :BANANA:

Ajamant · **Posted:** Wed Sep 14, 2011 10:01 am

WolverineFW wrote:

Ajamant wrote:

You need to rule out one problem at a time. I'm gonna guess you have not upgraded to the proper fuel head with an upgraded plug for the fuel heater to prevent major air leaks and lots of problems.

Search info on upgraded fuel head and you will find plenty of info. If there is no splicing of the wires into the plug on the drivers side of fuel head, then you have the old fuel head and need to upgrade. This is an easy fix and should be done before you start replacing injectors.

Someone please correct me if I'm wrong but the spark plug order is from front to back 1-2-3-4, so I'll assume the injectors follow the same order (assume???)

You have spark plugs in yours? :wink:

Yeah it was a little past my bed time when I wrote that

).

papaindigo · **Posted:** Wed Sep 14, 2011 10:09 am

Posting again as the first try did not "take"

Don't know that I can be much help but items to consider 1) the 2n gen filter head comes with a new filter already installed and you need to also get the new fuel heater wiring pigtail if you get that filter head; 2) rough idle can be a symptom of air having gotten into the fuel rail and it apparently takes time for that air to work it's way out; 3) I don't have a clue relative to the ordering # of the injectors but will note that the FSM indicates that the gasser injectors are numbered from front to rear and the typical numbering of cylinders for an in-line engine is front to rear so my bet is #1 injector is the front one and so on to #4 at the back by the firewall; 4) there have been a variety of reports of the injector wiring being installed backwards such that the #4 injector wire is hooked to the #1 injector which can fool a code reader; 5) your description of what happens when you pull the wire from each injector is odd; I could be wrong but as I understand it if you pull the wire on a good injector on a poorly running engine it should continue running but worse while if you pull the wire on a bad injector the engine should continue running but no worse so I don't understand why pulling any one of 3 injector wires kills the engine but pulling what I think is #2 (not #4) makes things a bit better; 5) if you do ID an injector problem don't run out and buy new injectors as they are servicable by a competent diesel injector shop; 6) the high-pitched screechy noise bothers me and makes me wonder about a fuel or air leak at that injector connector (perhaps the cause of that leak is disabled when you remove power from the injector).

Best I can do for what it's worth.

PS - Ignore comment #4 above. Brain cramp/stupid - it's the glow plug harness that's sometimes reversed. Duh my very bad.

mtgstuber · **Joined:** Tue Sep 13, 2011 4:15 pm **Posts:** 66

I found a local shop that will do diagnostics on the injectors. The owner was mentioning that if the injector was putting in too much fuel, or at the wrong time, it would explain why the engine actually runs better with it disconnected. Of course, I would thing the injection sequence would be controlled by the computer, so I'm not sure how the timing would be off.

I'm dragging it off to the shop tomorrow to have the injector pulled and diagnosed. I'll let you know what I find.

Sir Sam · **Posted:** Wed Sep 14, 2011 2:18 pm

Well before you do that, at least clean your map first, it's free and it needs to be done anyway at some point, and even though I would bet money on it not solving your problem there's no reason not to do it.

Joe Romas · **Posted:** Wed Sep 14, 2011 5:52 pm

mtgstuber wrote:

Of course, I would thing the injection sequence would be controlled by the computer, so I'm not sure how the timing would be off.

If a injector is bad there is no telling what is going on with it :frankie:

It's the GLOW PLUGS that often have the cable installed backwards. If the injector cables were reversed it would not run because the timing would be all off

ATXKJ · **Posted:** Wed Sep 14, 2011 8:08 pm

This was troubleshooting an injector
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=648881#p648881

CRD Misfire

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