AUSJEEPOFFROAD.COM Jeep News Australia and New Zealand - CRD not starting after flexplate replacement

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How long should the fuel rail hold pressure for??

I just did the test on mine for shits and giggles. Zero pressure before start, cranks and starts fine with rail pressure quickly to 300. Shut it down and went for an immediate restart. Just prior to the second start, and within 10 seconds of shutting it down, the rail pressure was already pretty much zero again. Tried again and same thing. DiagPro stayed connected well the whole time with continually changing data.

Pretty sure my starter is on its way out (new weird noise from it), but the engine still starts within 1 or 2 seconds of cranking.

Just wondering if I should be planning on future rail pressure problems or if this rail pressure behavior is seen by others.

Dont know how long it "should" hold pressure for, but of 3 different 2.7 crd powered WGs I have driven a bit they all lost rail pressure pretty much as soon as the high pressure pump stops.
So I guess thats normal,,

Quote:

Originally Posted by Wantsawillys (Post 1687407)

I know you want to get this thing running but honestly you're better off waiting for that code reader rather than faffing about. Trust me, you'll just end up getting frustrated with the jeep and start resenting it.
I have 2 in my yard right now that I can't get back to until I resolve some issues with my KJ which is my current daily driver.

That code reader and the wjdiag app are going to be your new best friend.
First thing to do when you get the reader is to read any codes and take a screenshot for later.
Then clear them so you start fresh (a lot of codes can be bogus and are set because of poor battery voltage, crank sync errors get set a lot because of this, and also from a poor starting event)
If you can start it with starting fluid (don't keep doing this) and it runs like crap, but you can't start it normally, i suspect you've got one (or more) of the following happening;
1. air in fuel. caused by bad o rings in the plastic fuel line connectors at the pumps and filter. Cheap fix, parts from mercedes dealer
2. low fuel pressure. caused by leaking high pressure pump, or faulty injectors with high leak off. Can also be caused by a faulty pressure regulator. The pump can be rebuilt with a seal kit for about $50, so can the pressure regulator. Leaking injectors means you need to replace them with new ones. Don't do refurbs, just not worth it. This is the most expensive thing to fix, and usually why crds are sold.

One of my WGs needs new injectors, because it is behaving the same as yours.
The other one has a fried (maybe) pcm because there is a fault in the wiring harness.

When you get the app, you'll want to go to the engine section, and pull up the real time data, and select the fuel pump pressure set point, fuel pump pressure actual, fuel rail pressure, fuel rail regulator sensor voltage / duty cycle pids and display them.
Crank the engine (not for long though) and see what pressure the pump gets up to. From memory it wants 250psi before it will turn on the injectors to start.

If you're not getting the pressure needed, then we can do other diagnostics.
The 'everything 2.7 crd' thread has a lot of this info in there, but i'm doing what you are so i can help

thanks for the detailed post, my code reader just showed up so will go have a look at it on the weekend, my brothers code reader is saying the pcm and tcm cannot be found
https://www.ausjeepoffroad.com/forum...6b23bd752b.jpg

Yeah, that's probably because the data port on the WG is not strictly OBDII.
You can plug in an obd2 reader and a very select few will get bugger all data from it.

That's why the WJdiag app is a must for these jeeps. Pay for the pro version, it's only a couple of bucks, the developer well deserves it.

I use that, and just a basic bluetooth obd2 dongle I bought from Jaycar for about $80.
I'm sure I could have gotten that cheaper elsewhere but I was in a hurry as always.

The WJDiag app can read everything, and talk to all modules, and lets you test and activate almost everything on the jeep.
You can also reset the transmission out of limp mode with it (which you WILL end up doing at some point) and that's usually a dealer only task.

You'll also find that you'll get codes with the reader that don't display when you do the key trick to read them off the odo screen.

Quote:

Originally Posted by RTB (Post 1687408)

Same for the 2 I have. And my KJ is the same.
My KJ lasts a little longer, maybe up to a minute, but then all the pressure is gone as far as the scan tool is concerned.
However if you crack a connection on the rail, there is enough pressure left for a pop and a squirt of diesel to come out, so it's not completely drained.

ok, so fuel pressure is getting upto 3000ish psi, what settings should i be looking at on the wjdiag app?

Quote:

Originally Posted by Straubz (Post 1687440)

ok, so fuel pressure is getting upto 3000ish psi, what settings should i be looking at on the wjdiag app?

3000ish psi is 200bar I can't recall what it needs to start, 200, 250 or 270 ( i might have said 250psi in previous post, i meant bar, brainfart.)

If you have a friend, get them to crank the car while you do the next test.
Standard disclaimer about not getting body parts stuck in moving engine parts.

Let's see if you're getting injector pulse as part of the starting sequence ie. fuel pressure ok, injectors are firing.

Grab a test light, take the wiring connector off the first injector.
Slap your test light ground lead onto the battery negative post.
Key ON, but not cranking here...
Touch each of terminals on that connector, one will be 12v live with key on, the other is ground.
The ecu pulses the ground on these injectors to fire them.
Once you have located the 12v constant, you're going to want to put your test light ground clamp on the positive battery post, and touch your test lamp probe to the ground pin in that terminal. Hold it there.
Now have your friend crank the engine.
Keep an eye on your test light and see if it starts pulsing.

If it does, great, ecu thinks fuel pressure is ok, and is trying to fire the injectors.
If not, we look into fuel pressure issues.
Either way we learn something and get to move to the next issue.

By the way, did you snapshot your codes, clear them and start from scratch?
What were the new codes generated when you tried to start the car?
Then after giving it a huff off starter fluid and the car actually started running, what were the new codes generated?