CRD Won't Start After Tranny Work- Coincidence?

Tucson Don · **Posted:** Mon Dec 05, 2016 1:31 pm

Howdy folks,
I just dropped a couple grand on my KJ CRD that was giving me some issues shifting in and out of 2nd gear in both directions, and the front wheel bearings needed to be replaced, since they were starting to make some noise at 135K miles. This rig has given me no trouble at all, and deserved the investment. So we ended up replacing solenoids and pressure transducer and filters and the guy tells me there was a cam or crank out of sync code, and if that happens sometimes folks think it's the transmission. I do take it off road, and pull a trailer occasionally so I don't mind putting in the money to keep it running. So after a week at the shop, upon driving it back to work after picking it up, I'm driving into the parking lot after a 20 minute drive and it starts making a loud noise, kind of like the noise it made when the turbo hose ripped. I was where I needed to be, so I parked and went into work. Four hours later I pick up my daughter then we drove home 30 miles away, no issues, the jeep' running like a champ. The next day on the way in, in the morning, after driving 20 minutes at 72 MPH and maybe a couple of stop lights, as I try to accelerate I realize that there is no power. Well since I was a couple of miles from work, my daughter and I (momma had the other vehicle at the airport as she was out of town on business) swapped the jeep for the VW and I took her to school and came back. I got a work buddy to drive behind me at lunch as I took the jeep home. It ran fine for the first 15 minutes then again it had no power. Now this trip home has an uphill climb and at the steepest portion I was able to keep it above 55 MPH (slowed down from ~65) by the peak of the hill. Down hill I didn't have to push 100% throttle input to maintain 75 MPH, but close to it.

I went out the next day to diagnose it, and as I started it up to listen to what was going on, it ran for 15-20 seconds and then stopped. It hasn't run since, but it cranks like a maniac with the good battery. I purchased an analyzer and found that modules $12 and $41 are not responding, and I had a code P0093 that the manual says is excess fuel rail pressure over and above what was expected, but the analyzer says is a major fuel leak. I don't believe there's a fuel leak, nothing's wet. I read on this forum that the cam and crank position sensor failures won't allow the engine to start but won't throw a code (which contradicts what the guy at the tranny shop said: that there was an indication that they weren't seeing the same RPMs), so I changed them. Still nothing.

Does anyone have any ideas? What is the $41 module?
Thanks for any help. In the meantime, I've washed my hands and will :rockon:

for the evening.
Thanks,
Don

WWDiesel · **Posted:** Mon Dec 05, 2016 1:50 pm

Have no idea what the $12 and $41 modules are; tried to find something on them on line with no luck of anything that made any sense!

Does the manual that came with your scanner give you any info on the DT numbers?

If I am reading your post correctly, you have replaced the cam and crank sensors twice?
As you stated the motor was running fine before the transmission work and 2 sensor replacements, I would strongly suspect one of the new sensors is bad or a wiring got pinched or damaged in the process of some of the work performed? :roll:

I know a bad CPS will not let the motor start!!! Been there....

Tucson Don · **Posted:** Mon Dec 05, 2016 11:13 pm

Both sensors just once, but it took two days, ...does that count?
I'm not as young as I used to be and lying on the ground reaching up to get the Crank sensor was a bear. I need a comfy heated garage. The manual with the scanner gives a web site that charges $1.99 for the list of the most common repairs when that code is thrown, if they have that info. It might be worth a try, but here's potentially a better question:

Will a failed common rail pressure sensor keep the engine from starting, and when that sensor fails does it fail at 100% output (which would have to be some ridiculous pressure like 25,000 or 30,000 PSI)?

The crank sensor was showing on the scanner that the starter had it spinning at 254 RPM, but I haven't checked it since I put in the new sensor. It'd be something to have damaged the wires on re-installation, but here's the kicker: That test before was with the cam position sensor changed, and yes, I tried starting it after replacing the cam sensor. What I did not realize at that time was that the crank signal showing the RPM indicated that it was good! Anyway this implies that there is some other issue preventing fuel from being injected. This P0093 Fuel System Leak Detected - Large Leak I pulled information off of this and it says the Fuel Rail Pressure was 10025.01. Maybe the fuel pump is bad, but I found no evidence of diesel fuel anywhere. Is it possible there could be a leak that wouldn't be external?
Thanks for any help

The real kicker is the service manual says that to set a

Quote:

P0093 - FUEL RAIL PRESSURE MALFUNCTION POSITIVE PRESSURE DEVIATION
on page 9 - 736 ENGINE DIESEL DIAG KJ
Set Condition:
The signal from the fuel pressure sensor indicates the actual fuel pressure is above the fuel pressure setpoint.

I've got to get smarter at this instead of replacing things that aren't broken. The above manual quote says to me that the code was set before this current issue. Could the fuel pump have over-pressured and blown a seal?

WWDiesel · **Posted:** Tue Dec 06, 2016 12:09 am

Have you tried pumping and bleeding the fuel system using the fuel filter head manual pump and making sure there is no air in the fuel system?
Just another item that needs to be ruled out! :wink:

flash7210 · **Posted:** Tue Dec 06, 2016 4:08 pm

Tucson Don wrote:

Will a failed common rail pressure sensor keep the engine from starting, and when that sensor fails does it fail at 100% output (which would have to be some ridiculous pressure like 25,000 or 30,000 PSI)?

A failed rail pressure sensor will not keep the engine from starting.
It will result in a high pressure reading, even if just unplugged, of ~26,000 psi.

P0093 is a fuel system leak
P0193 is a failed rail pressure sensor

I believe you have a air-in-fuel problem and should focus you attention at the fuel filter assembly.

rankom · **Posted:** Tue Dec 06, 2016 10:38 pm

well may be good idea to pull GP and check compression , assuming you did check fuel system , if you don't have compression tester , you can blow shop air in cylinders , at TDC 1,3,4.2 no leaks is a good sign.

Tucson Don · **Posted:** Tue Dec 06, 2016 11:29 pm

I have an old compression tester I'd have to dig out of the 'seldom used' tool drawer if the fuel issue turns up a dead end. Although I suspect if the compression was bad, wouldn't it be bad from that point on, and not an intermittent fault, as a broken ring or valve or worn guide (hopefully not at 134K miles), and would a compression issue prevent starting? Thanks for the input.

joe_ · **Posted:** Thu Dec 08, 2016 6:19 pm

It seems like there's some discrepancy on what P0093 means. According to the service manual, it means positive rail pressure deviation, but according to GreenDieselEngineering it means

GreenDieselEngineering wrote:

The 0093 code is telling you that the pump is not able to deliver enough fuel to pressurize the fuel rail properly.

[source]

Which would likely point to either air in the system, a leaky injector, or a failing fuel pressure solenoid.

----------
Edit: here's some more info from that thread that may be useful

GreenDieselEngineering wrote:

Here are the main causes for the P0093 error code: air leakage in fuel supply line, stuck open injector, leakage on high pressure side and PCV deviation from expected set point. The last one listed concerns the pressure control valve (PCV) on the back of the high pressure rail. We have seen a few of these parts fail in the field and is will cause an immediate shutdown of the engine. Still, failures of this component are very rare and it might be internal debris preventing the PCV from closing completely. Don't really want to tell you this is for sure the problem as the parts is not cheap and it is near impossible to prove the failure short of trying a new PCV. PCV part number is 5159964AA and sells for around $470 online.

[Take that price with a grain of salt; the post is from 2010.]
[source]

----------

Tucson Don wrote:

I have an old compression tester I'd have to dig out of the 'seldom used' tool drawer if the fuel issue turns up a dead end. Although I suspect if the compression was bad, wouldn't it be bad from that point on, and not an intermittent fault, as a broken ring or valve or worn guide (hopefully not at 134K miles), and would a compression issue prevent starting? Thanks for the input.

I don't think you'd be able to use a standard compression tester on this engine as that's probably designed to connect through spark plug holes. With this engine you'd have to connect a compression tester to the (non-threaded) injector holes ... the tool listed in the service manual is the VM.1072A. But I agree, I can't see something like that being an intermittent problem.

Tucson Don · **Posted:** Fri Dec 16, 2016 6:33 pm

So here's the latest update:
I have changed out the cam position and crank position sensors. No effect. At least I didn't screw up either one during re-installation (whew). I got the fuel filter changed out, but it didn't help. When removing the hoses (not the banjo bolts) I noticed that they were both dry, but I expected to get diesel fuel on my hands at least on the tank side. This may be an important detail, so I wanted to bring it up. I was able to pressurize the filter and drained out the air I could get out of it, but still it didn't start, so I had it towed to the shop. Their guy connected up a vacuum to the HP pump inlet and sucked fuel all the way to it, and then it started. So he ran it last night and thought everythying was ok. Since they didn't find a root cause I wanted them to try it again this morning. When he took it out, it lost power. He doesn't have any special tools so they're telling me I have to send it to the Jeep dealer to get it diagnosed.

I don't know how the suction line can be dry if there isn't a leak between the tank and the filter. If anyone would please comment on this specific point, I would appreciate it very much.

Second issue, if it is the gear pump on the HP pump that is bad, how is the air getting in, and would getting a lift pump really help, or is it that the $1299 fuel pump (parts only) is going to go out soon, and the lift pump puts that off for a matter of mere months?
Thanks guys.

ebbnflow · **Posted:** Fri Dec 16, 2016 6:53 pm

If it started when air was removed, your CP3 high pressure pump is working. You have an air intrusion issue between the CP3 pump and your tank. The most common place for air to enter it through the filter head and/or the quick connect fittings on the top of the fuel tank.

flash7210 · **Posted:** Fri Dec 16, 2016 8:23 pm

Quote:

I don't know how the suction line can be dry if there isn't a leak between the tank and the filter. If anyone would please comment on this specific point, I would appreciate it very much.

Thats just it, there IS a leak.
But the leak is letting air in, instead of fuel leaking out. So you may not find any drips.

The most likely source is the fuel filter head and the two electrical connectors on it. Pull those plugs out and check for wetness inside.

The connections back at the tank can also allow air to leak in.

A lift pump mounted back at the tank will keep the fuel line pressurized and fuel filter full of fuel. This way, if there was a leak, if would be plainly visible

papaindigo · **Posted:** Sat Dec 17, 2016 10:50 am

If I'm reading all of this I do not see any mention of which fuel filter head you have - 1st gen which has 2 black/dark brown electrical plugs or 2nd gen which has a bright blue plug on the right (viewed from the front) side - although I do see you have put on a new fuel filter. If you have a 1st gen head replace it as it's a known source of air in fuel - NOTE it comes with a new filter so you can just save that filter of the lightly used one you just installed. Also I see you bled the filter head but not how you did it. Proper bleeding procedure is critical - see this video for bleeding and images of the different OEM filter heads https://www.youtube.com/watch?v=qPwGcWi3gE0 . I'd add a bit of vinyl tubing from the bleeder screw to a catch can keeps the mess down.

If you don't close the bleed screw between episodes of pumping the primer you will never get air out of the system.

Tucson Don · **Posted:** Sat Dec 17, 2016 11:40 am

I need to figure out how to turn this saga into a book to recoup some of my money.
Here's the latest installment. This morning at O-dark-thirty our hero headed out to drive 55 miles to the dealer who had the best service rating on google. The other guy is a known shyster so we try not to go there despite him being 18 miles closer. The svc manager at the good place spoke with me last night and said for $125 they'd be able to tell me what was wrong; that they'd then use my parts or theirs; and get my rig back running. I'm thinking if it drove home last night and then 2 miles this morning, that the pump is OK and I've got a fuel leak. The mrs. wants me to send it to the shop, but I don't want to spend the cost of the repair on towing it if I can fix this :furious:

rhymes with witch!

I can't figure out how to insert a picture of my fuel filter head, but it is the 2 black plug one described above. Where does this new filter head come from? Is one better than another? If I change it out and it's the fitting at the tank and I still have a leak, I'll be :dead:

as the wife will Keeeel Meee!

Also, the service manager said there was a lift pump in the tank but at higher engine speeds it is overcome by the suction of the CP3 pump. Is this accurate? I can imagine they use the same tank as the 3.7L sparky which I also can imagine needs to have a lift pump in it. Logically, if I don't see liquid in the filter's electrical connections that doesn't necessarily mean there isn't a leak there, because the whole suction line is under vacuum. Right? Thanks again for all your help.

WWDiesel · **Posted:** Sat Dec 17, 2016 11:58 am

Tucson Don wrote:

Also, the service manager said there was a lift pump in the tank but at higher engine speeds it is overcome by the suction of the CP3 pump. Is this accurate?

The service manager is an idiot! Unless a previous owner installed an in-tank lift pump, IT DID NOT COME OEM!!! I would run from them quick; most dealer shops are clueless when it comes to working on Jeep CRD's! :furious:

Also, if it had an in-tank lift pump, you would not be dealing with air inleakage problems period!!!! :!:

Your best bet, install an in-tank lift pump,
A properly installed in-tank lift pump will ensure absolutely NO air infusion into the fuel system period! :!:

An in-tank lift pump puts the entire fuel system under a positive (+) pressure from where it first exits the fuel pump inside the fuel tank through all the fuel lines and fittings, through the fuel filter head, heater, and filter, all the way to the back of the CP3 injection pump.
ANY LEAK anywhere on the system will BE SELF EVIDENT and show up very quickly as fuel leaking out.
Air simply cannot get into the system while it is under 10-15 psig of pressure!!!

These two links below will answer any questions concerning installing an in-tank lift pump and / or wiring it up properly.
http://www.auerbach.ca/kj/lift_pump/
viewtopic.php?t=26385&highlight

Right now, your CP3 is trying to suck the diesel fuel all the way from inside the fuel tank through the fuel lines and fuel filter to the back of the CP3 pump...NOT A GOOD DESIGN!

As to the fuel fittings at the tank, they are designed to seal under pressure, not vaccum, therefore they will seal and work just fine with an intank pump. If you decide not to install an in-tank fuel pump, then you should remove them and use good quality diesel rated fuel line hose with screw type hose clamps to insure no air inleakage at the fittings... :roll:

papaindigo · **Posted:** Sat Dec 17, 2016 1:01 pm

I'll part company a bit with WWDiesel at this point. But before that a bit of background
1. my bet is you spoke to a service writer not service manager but either way WWDiesel is correct that person and/or the tech is an idiot. The fuel lines from the tank to the filter head are identical on the KJ CRD and gasser. The difference is the gasser has a fuel pump integrated with the fuel level sending unit inside the fuel tank and obviously has no CP3. The CRD has ONLY a fuel level sending unit in the tank and a CP3 (combined fuel pump and high pressure pump) in the engine bay.
2. there is absolutely nothing wrong with a fuel pump in the engine bay. Vehicle were designed this way for decades until somone figure out how to place a pump in the tank without setting the tank on fire. However, absent solid fuel line from the tank to the CP3 any leak point in that line will tend to suck air into the line and if between the tank and the filter head that air gets trapped at the top of the filter head and ultimately blocks the flow of fuel to the engine.
3. possible leak points - a) in the filter head (primer shaft, bleeder screw, filter to head seal especially if you did not remove old inner filter gasket, AND a burned filter heater element which won't necessarily leak fuel out although if you stuffed a "Q" tip in the recess I bet you would smell fuel once "Q" tip is removed) and/or the 2 fuel supply line quick disconnects back by the tank which do better at sealing under pressure (for the gasser) than no pressuer (for the CRD).

What you need to do:
1. before anything else replace the filter head. If it's 1s gen that that IS a source of air as it is leaking and pump won't fix that. Source http://www.idparts.com/updated-fuel-fil ... -4723.html . Easy DIY job - unscrew fuel line clamps and push them off/don't pull; unbolt head from bracket; lift up gently and unplug WIF sensor on bottom of filter; reverse to install new head and filter; hook up new wiring (undo battery; there are 2 identical sets of wire use only one set; thread wires thru new plug and secure with the obvious clamp; cut old heater element wires; splice in new wires matching as close as possible by color; splice can be good butt connectors or solder; plug in; hook battery back up; prime filter). This may fix your air problem; it did for me and my son
2. if it does not fully fix your problem then you need to deal with the 2 connectors back by the tank. Cheap fix - drop tank; remove quick disconnects; replace with marine grade diesel rated fuel line and clamps; put tank back up. Less cheap fix what WWDiesel says.

Tucson Don · **Posted:** Mon Dec 19, 2016 11:01 pm

I found a shop that knows diesels close enough. He's got it and will run a pressure test on the fuel lines on either side of the fuel filter and let me know what he finds. He's willing to install the lift pump as well if I really want them to. So, what's the skinny here? This rig hasn't had much of anything except bigger 235/75 tires and regular maintenance and it'll climb a tree if I need it to and she got up to 130,000 with not much invested. We regularly go off road, so I figure with the desert pin-striping I've put on her, if something bad was going to happen it'd have happened way before now. That is, do I need a lift pump if I change out the QD fittings and all the hoses if it got me 10 years without needing it? Or, and I trust there are some of this persuasion out there as well, should I give the 10 year old pump a hand to ensure I get another 10 years out of it?

The filter has a light blue wire going to the plug on the left, and like I said, it doesn't look wet anywhere, so I'm holding off on replacing that one until and unless the other maintenance doesn't fix it. I've asked for the last 12" or so going to the filter from the tank to be replaced with clear tubing also.
So, what's the prevailing wisdom here lift pump or unnecessary?
Thanks for all the great advice.
Don

WWDiesel · **Posted:** Tue Dec 20, 2016 1:11 am

Tucson Don wrote:

So, what's the prevailing wisdom here lift pump or unnecessary?
Thanks for all the great advice.
Don

Many on this forum and a few others I know have installed the in-tank lift pump to ensure no more air inleakage into the fuel system!
While there are a few who do not believe they are necessary. :roll:

I can tell you from my own experience that the engine runs better with the positive pressure fuel feed of a lift pump and I believe others who have installed them can attest to similar results.

Bottom line, A properly installed in-tank lift pump will ensure absolutely NO air infusion (leakage) into the fuel system period ever again!
Make your best choice... :juggle:

racertracer · **Posted:** Wed Dec 21, 2016 4:24 am

did you try to detach and reattach all the harness connectors that connect to the transmission sensors.

There may be 2 or 3 connectors... I don't remember.

Tucson Don · **Posted:** Wed Dec 21, 2016 9:35 pm

Unfortunately I allowed myself to be spooked by the VW buy back, thinking I would soon be a 1 car family living in the toolies with a school-aged child, and my wife and I had it towed to a reputable shop. Their last update is that they traced it back to the filter housing having an internal leak. I had that :furious:

in my hands and it looked to be in great shape, and I congratulated my dumb booty chocking it up to the good care and maintenance I mostly do. :roll:

So they're going to run it cold tomorrow for a 20 minute drive and it will supposedly be fit as a fiddle. I told him to try and drive it home and back tomorrow and let me know. He says it doesn't need the lift pump. I'll have to install it myself when/if I get it back tomorrow. Merry Christmas. The repairs would be equivalent to a good epiphone acoustic :rockon:

I'm bummed, but the opportunity cost was:
Tow it back: $100
New Filter Housing $129
Shop diagnostic fee $226
Pissed wife the dead jeep is back $100 (at least)
Time to do it myself 3 hours $225
Total? more than the rape of $580 I'm paying this shop.

Team, this was a simple fuel issue. I can do this. I do have the time, tools ...mostly, and smarts.
What special tools do I need please? So I never have to pay to have a diagnosis again?
Vacuum tank, pump tubing? Gauges? What?!!
As always: Thanks!

rankom · **Posted:** Wed Dec 21, 2016 11:06 pm

like WW diesel said ,,, if you can the best upgrade is a in-tank lp. second gen. FF head is same as 1st gen except has better heater plug , i replaced twice under warranty i re re tank twice instal marine grade fuel line (REMOVED PLASTIC QUICK CONNECT HOSE) air was coming in again , so i installed pump and and reinstall all original quick connect hose and same FF head that was sucking air , so since i did this no more problems,

CRD Won't Start After Tranny Work- Coincidence?

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