Just replaced head and have no start

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

We have a Liberty in our shop that I replaced the head and timing belt on. It ran before but had code P2294 for fuel rail pressure solenoid. After replacing the head, it did start and run for about 30 seconds and then died. I am getting 5v at the fuel pressure solenoid. I measured resistance and it is 3.8 ohm. it is also dumping fuel out of the return. It has brand new injectors and the fuel filter housing has been updated. Should there be 12v at this solenoid? I measured resistance from ECM and the wires are good. I checked voltage at ECM for the fuel pressure solenoid and it is 5v at the ECM. I want this thing out of the shop. It has been here too darn long!

geordi · **Posted:** Thu Mar 05, 2015 4:16 pm

For a fuel pressure code, why did you remove / replace the head? I'm genuinely confused by that.

The reason it won't start is called air in the fuel.The usual method I use is to crack the #4 injector line and then manually spin the fuel pump until all the air has been expelled from the rail. Even then, it will still be difficult to start, but it will eventually fire when all the air is finally purged.

Crank for no longer than 5 seconds at a time with 15 seconds rest in between to let the starter cool, and having a battery charger connected will help keep the battery from going too low to run the computer. Usually fires in less than 5 attempts for me when I do it this way.

flman · **Posted:** Thu Mar 05, 2015 5:32 pm

Like Geordi said air in fuel, or maybe you mixed up a connector from the rail and plugged it into the sensor, one of those connectors can get mixed up.

For me I usually loosen the fitting at injector 1 because it is easier, plus gravity makes the air come out of the front of the rail considering the front of the engine is higher. If you do not have elctric lift pump you will need to crank the engine, until it leaks out fuel.

geordi · **Posted:** Thu Mar 05, 2015 5:57 pm

I don't think it is the connector, because he said it ran for about 30 seconds.

Coincidentally, 30 seconds is just about how long it would take at idle to swap all the fuel in the injector lines... With air.

flman · **Posted:** Fri Mar 06, 2015 7:48 am

geordi wrote:

I don't think it is the connector, because he said it ran for about 30 seconds.

Coincidentally, 30 seconds is just about how long it would take at idle to swap all the fuel in the injector lines... With air.

Well you got me there Geordi. OTOH, I never tried to start one with no bleeding, so do not know how long they run this way?

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

It originally came in because it died and would not restart and the customer wanted the timing belt replaced. I replaced the timing belt and it ran but was popping. Took the valve cover/cams off and found several broken lifters and bent valves. Had head done and put it back together. It started and ran fine for about 30 seconds. It does not have air in the system, it has been bled several times. The customer had it at another shop and they had codes for fuel rail pressure solenoid and they replaced it as well as the fuel/water separator. It still has those codes, so I checked it out. It ohms within spec, has 5v going to it. It dumps fuel out the return. The snap on scanner says it is building 1600 psi in the rail

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

P2294 is a fault for open load on the PCV. Our guess is a leaking PCV on the back of the fuel rail. You need to see about 3500 psi in order to enable the injectors to fire during cranking.

The other item to check is pulling the injector backflow tubing from each injector during cranking one at a time and see if there is excessive backflow or bubbles coming out. It could be a bad injector, but this is a long shot as the fault code typically would be different.

Hope this is helpful.

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

It has a new pressure solenoid on it. I don't want to take it out and charge the guy and find out that wasn't the problem. Can anyone tell me how much voltage the solenoid is supposed to be getting? Its only getting 5v and the ECM is only putting out 5v. Should it be 5v or 12v? If its supposed to be 12v, them I am leaning toward the ECM. I know it could have been a bad solenoid out of the box. I called the dealer to ask about the voltage and got laughed at. He said they wont even work on them

Mountainman · **Posted:** Fri Mar 06, 2015 1:21 pm

Just takes a minute to pop the returns off the injectors to check if one is squirting lots of fuel by like GDE said, if you see one that puts out way more fuel that the others while cranking, then you might have it. I think it is 5v, but I'll try to look it up for you.

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The PCV is 5 volt max.

Mountainman · **Posted:** Fri Mar 06, 2015 1:59 pm

GreenDieselEngineering wrote:

The PCV is 5 volt max.

Hey Keith,
The valve is held shut by a spring or permanent magnet right? So, if it's getting 5v, then that's wide open isn't it? Or do I have it backwards? Just curious if it could be the ECU giving the wrong analogue value in this case?

geordi · **Posted:** Fri Mar 06, 2015 2:27 pm

I hear a lot of hoofbeats right now... I wonder where the rainbow unicorn zebras are off to?
Or... Maybe the most likely source would be a horse?

The ECU is the LEAST LIKELY source of the problem. The fuel metering valves and injectors are designed to work against the pressure of FUEL and if there isn't a full complement of "not air" in the fuel rail and lines and injectors, then the results are questionable at best. Codes are likely because the computer doesn't know what is happening, it has no way of detecting air in the fuel.

In all of the CRDs on this forum that I have read about, I have heard of exactly TWO with failed ECU. One was in Argentina and failed under unknown circumstances - but the computer was completely dead. The other had a power surge from a jumpstart or something else electrical and was partially fried... But was acting all sorts of goofy. It was obvious what was wrong. You don't have this problem, and you are starting to sound like the dealerships that pick the most unlikely (and most expensive) component and point at that as the solution. I'm surprised that your local dealership would be so open about refusing to work on the CRD, and shocked that they refused in the first place. Usually they are happy to take your money and make the problems worse.

Obviously you don't want to do the same thing, so I will try to explain what is happening here.

If you think that pumping the primer button on the fuel filter will fill the high pressure side of the system... Sorry, no. Not even close. That primer button ONLY brings fuel forward to the filter from the tank, and then you open the bleeder screw to get the air out, close it, pump it up again, open the bleeder to get more air out, rinse and repeat until there is only fuel coming out.

You have now purged the fuel lines from the tank through the filter to the back of the fuel pump. No further. The high pressure side of the system is still not filled, the ONLY WAY to fill it and get the air out is to spin the fuel pump pulley clockwise while having an injector line cracked at the fuel rail. That rail holds a decent amount of fuel, and by being replaced and open so many times, it is guaranteed to be bone dry by now.

Once there is a decent amount of fuel at the injector nut on the rail, seal that nut and NOW you are ready to start. It will STILL probably take 2-3 cycles of 5 seconds cranking and 15 seconds resting, but it should finally fire. Ignore all codes until you have done this, as the computer isn't getting accurate information. Also, if the battery isn't up to snuff, the voltage during cranking will dip too low, and the computer could reboot or certainly would be getting very confused when it discovers that 2+2=6. Power is important and the starter pulls a lot of it.

Good luck, get the air out of the high pressure side and it should fire right up. These things are fairly simple to get started, keeping them efficient is the hard part.

Mountainman · **Posted:** Fri Mar 06, 2015 2:37 pm

Hey, at this point the dealer would have been like, you need a new engine, period. :mrgreen:

geordi · **Posted:** Fri Mar 06, 2015 2:58 pm

Mountainman wrote:

Hey, at this point the dealer would have been like, you need a new engine, period. :mrgreen:

True enough, and HEY, look at that, we have a whole selection of them, complete with new bodystyles and a fresh payment to our profit line!

papaindigo · **Posted:** Fri Mar 06, 2015 3:06 pm

Just to make sure everyone is on the same page:
1. what geordi says about priming and battery "health" are both correct.
2. I assume since it ran briefly that the #4 injector and identical sensor plug have not been swapped.
3. what you get for rail pressure and what GDE says you should get suggest insufficient fuel rail pressure to fire and run. 1s suspect would be back to comment #1 above. 2n suspect would be excess return from 1 or more injectors, 3r suspect would be the 2 sensors on the rail - IIRC one tells the ECU you have enough pressure (might be misreading hence no crank) and the other returns excess fuel (if stuck open no pressure no crank)
4. I remember the Argentine dead ECU and the only other one I recall was in TX when a lightning strike on an adjacent tree fried most of the electronics (I'd dig up the member's name but it's not worth the bother).

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

I started at #4 and bled each line. There is plenty of fuel coming out. From what I understand, there should not be any fuel coming out of the return on the PCV. This thing is dumping as much as the pump is pumping. This has 5 volts. We hooked a test light to see the wire that pulses, and it would not light the light, but the 5 volt is there when the key is on

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

The injectors are all new. I checked and they all have good return

flman · **Posted:** Fri Mar 06, 2015 4:18 pm

confuzed wrote:

I started at #4 and bled each line. There is plenty of fuel coming out. From what I understand, there should not be any fuel coming out of the return on the PCV. This thing is dumping as much as the pump is pumping. This has 5 volts. We hooked a test light to see the wire that pulses, and it would not light the light, but the 5 volt is there when the key is on

I would think voltage would tend to close it, because when you shut the key off there should be none and it would open.

One time my CRD was throwing a code that could have been the pump, the MPROP or the PVC.

So I played around and unplugged things with the engine running, what fixed it was unplugging the PVC and cranking it with a hose into a can, I think it was sticking and that seemed to solve it for over a year or two. Maybe something is in the seat of the PCV on the one you are having troubles with, or just stuck? You might try pulling one of the injector line fittings off the rail and blowing compressed air into the PCV to see if something comes out of the rail?

Found the thread, mine was a P0093 viewtopic.php?f=5&t=76078&hilit=PCV

confuzed · **Joined:** Thu Mar 05, 2015 3:07 pm **Posts:** 7

Im thinking there may be some reason it is stuck open. I tried blowing air into it, but I didn't change anything. I am having the customer contact the dealer that installed it to see if they would cover it under warranty if I removed it. We will see what happens

geordi · **Posted:** Fri Mar 06, 2015 6:16 pm

I can tell you their most likely answer on that: "electrical component, no warranty or return once installed"

Sent from my iPad using Tapatalk HD

Just replaced head and have no start

Who is online