2005 liberty crd UPDATE 9/2/18 Compression results

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

rankom wrote:

dont run it on ether any more , we need report from your fuel injection shop, a print out of injector tests. and compression test results

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

Tear down begins Friday!
Wish me luck!!

rankom · **Posted:** Wed Aug 15, 2018 9:46 pm

ok good , if you need to skip the compression test , take it apart ,but that still does not explain why its not building fuel rail pressure , anyhow ,keep us posted with what you find

GordnadoCRD · **Posted:** Wed Aug 15, 2018 9:52 pm

Rankom, it runs on 2 cylinders, so it IS getting fuel pressure.

Something is preventing properly metered and timed fuel from being delivered into properly compressed air in the other 2 cylinders.

rankom · **Posted:** Thu Aug 16, 2018 3:16 am

thanks Gornado , so fuel rail pressure is ok , i said compression test , and check for broken rockers ,,, LOL

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

rankom wrote:

thanks Gornado , so fuel rail pressure is ok , i said compression test , and check for broken rockers ,,, LOL

Yes the rail pressure is fine now
I believe it had to be something with the ecu plug since that’s the only thing that I messed with after re installing the injectors. That’s why it’s building rail pressure now.
It’s not firing on all four cylinders due to rocker/lifter failure is my thoughts

It will pass compression test with broken rockers see the following thread:https://pawlikautomotive.com/2005-jeep-liberty-diesel-rocker-arm-replacement/

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

Update 8/25/18 cover is removed and all rockers are fine
Lifters are ok too

Unsure where to go from here

Now I am thinking it has a electrical issue from ecu to the injectors

Or maybe the ecu has a fault in the injector driver for the 2 cylinders not running

Mountainman · **Posted:** Sat Aug 25, 2018 11:12 am

I didn't read the whole thread again, but did we maybe miss something obvious, like air in fuel? Really common and can make it feel like it's running on two cylinders

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

Mountainman wrote:

I didn't read the whole thread again, but did we maybe miss something obvious, like air in fuel? Really common and can make it feel like it's running on two cylinders

I will re assemble the upper half of head and then try and start it again
I can crack a line at the Injectors that are not firing and see if it fixes it

I will also put a clear plastic line on the feed side of the filter head

FWIW I can unplug the two injector plugs on the dead cylinders and it runs the same...

Grotsoldaat · **Posted:** Sat Aug 25, 2018 1:03 pm

98tdi wrote:

Update 8/25/18 cover is removed and all rockers are fine
Lifters are ok too

Unsure where to go from here

Now I am thinking it has a electrical issue from ecu to the injectors

Or maybe the ecu has a fault in the injector driver for the 2 cylinders not running

Sounds more than possible, as everything else has been checked. ECU can malfunction as well as connections.

WWDiesel · **Posted:** Sat Aug 25, 2018 1:32 pm

Mountainman wrote:

I didn't read the whole thread again, but did we maybe miss something obvious, like air in fuel? Really common and can make it feel like it's running on two cylinders

Reread whole post; if it were air in fuel wound not the fuel rail pressure be low and fluctuating wildly and would not affect just the same two injectors/cylinders on every startup?
Injectors, some wiring, and lifters/rockers have all been ruled out. I agree it sounds more like an electrical problem.
About the only thing left is possibility of some broken or shorted wires in the harness or a problem in the ECM connection or ECM itself.

I would strongly advise the purchase a NOID OEM Injector Signal Tester like the one below that Autozone sells.
Will be one of the best $25 you ever spent.
They are priceless when it comes to testing receiving actual electrical signals at the injectors when you don't have fancy expensive test equipment.
I have a much larger set that I have used many times including on injected boat motors and they work and work well.

Part Number: 27161
https://www.autozone.com/test-scan-and- ... 948078_0_0

rankom · **Posted:** Sat Aug 25, 2018 3:47 pm

all the above suggestions are correct , but there is no fault codes in ECU about 2 cylinders in question , that is why i was asking for fuel injection shop test report and we have it , but we are still missing compression test values, and that is one of the steps that we do when injectors are out

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

WWDiesel wrote:

Mountainman wrote:

I didn't read the whole thread again, but did we maybe miss something obvious, like air in fuel? Really common and can make it feel like it's running on two cylinders

Reread whole post; if it were air in fuel wound not the fuel rail pressure be low and fluctuating wildly and would not affect just the same two injectors/cylinders on every startup?
Injectors, some wiring, and lifters/rockers have all been ruled out. I agree it sounds more like an electrical problem.
About the only thing left is possibility of some broken or shorted wires in the harness or a problem in the ECM connection or ECM itself.

I would strongly advise the purchase a NOID OEM Injector Signal Tester like the one below that Autozone sells.
Will be one of the best $25 you ever spent.
They are priceless when it comes to testing receiving actual electrical signals at the injectors when you don't have fancy expensive test equipment.
I have a much larger set that I have used many times including on injected boat motors and they work and work well.

Part Number: 27161
https://www.autozone.com/test-scan-and- ... 948078_0_0

Thank you for the info, I will purchase that tomorrow and see what happens

98tdi · **Joined:** Tue Jul 17, 2018 5:42 pm **Posts:** 24

rankom wrote:

all the above suggestions are correct , but there is no fault codes in ECU about 2 cylinders in question , that is why i was asking for fuel injection shop test report and we have it , but we are still missing compression test values, and that is one of the steps that we do when injectors are out

I will check and see if my Vw compression kit works on this motor 10x1.0 tread pitch is what vw glow plug threads are

Also does anyone have a injector color chart to make sure the wires that I hooked up to the injectors are indeed the correct one for that cylinder??

rancherman · **Posted:** Sat Aug 25, 2018 8:03 pm

I'd imagine if there were 2 cylinders not firing, but is in fact injecting all 4... there would be a fair cloud of vapor out the tailpipe. If no excess 'cloud'... then the converse should be true; Those injectors are not delivering fuel.
Did you 'eyeball' across the valve stem tops?

Unscrew the oil fill cap and see if anything more than a little blowby comes out the hole when you are cranking or when it's running on 2 cylinders..

Mountainman · **Posted:** Sat Aug 25, 2018 10:36 pm

98tdi wrote:

Mountainman wrote:

I didn't read the whole thread again, but did we maybe miss something obvious, like air in fuel? Really common and can make it feel like it's running on two cylinders

I will re assemble the upper half of head and then try and start it again
I can crack a line at the Injectors that are not firing and see if it fixes it

I will also put a clear plastic line on the feed side of the filter head

FWIW I can unplug the two injector plugs on the dead cylinders and it runs the same...

Ok, unplugging those two should rule out air. Definitely verify the wires are going to the right injectors, and ohm those puppies out from the ECU

geordi · **Posted:** Sun Aug 26, 2018 10:37 am

Got your email, replying here as hopefully this will help you as well as someone else

The injector lines shouldn't be able to be messed up if the harness is mostly intact, they aren't long enough to easily reach another location, BUT that should also immediately set off a cylinder misfire code. If you aren't getting misfire codes, then there MAY be electrical issues, but there may also be compression issues. Did you look at the valve stems with a straightedge? It *should* be obvious if there is an issue with one valve or another, but it could be subtle too.

I don't think you have a valve issue in two cylinders, but it is not unheard of - but the engine usually doesn't stay running with that!

Any luck on a compression test?

Sir Sam · **Posted:** Sun Aug 26, 2018 11:15 am

I just finished repairing yet another CRD with bad rockers.

Can you post a picture of your rockers? are you sure there is ZERO play in the roller bearings?

Many years ago I had a Jeep that I think was the first case of failed rockers we had seen on this board, the rockers had worn and failed so evenly it took awhile to realize the rockers were the problem. I took the intake off and on many times and retimed and hooked up everything many times before I figured out the issue. be prepared to reinstall just enough to do further checks.

It IS possible to have crap compression but a good leak down. the leak down test is more valuble than the compression test. If you can get a good leakdown you know the issue is not with the mechanical sealing of the valve seats and rings.

As stated you should loop check the injector circuits, unlikely to be the problem, but it is easy and free to check.

Use this PDF and the highlighted circuit and check for continuity along each circuit path:
http://colorado4wheel.com/manuals/Jeep/ ... rs_ecu.pdf

Last week when I did this I installed a spare ECU to verify there were no faults on either injector driver. The bosch ECU is unique in that is has a transistor on both the high and low side driver, so a failure of the transistor on either line would cause a failure. That said it would be really weird to have more than one simultaneously fail. You will likely need a scope to verify the signal, I could not ready frequency or voltage with my fluke when the engine was running.

Maybe hookup the injector to the rail but keep it pointing outward to verify it is spraying out fuel.

WWDiesel · **Posted:** Sun Aug 26, 2018 12:23 pm

Quote:

I could not ready frequency or voltage with my fluke when the engine was running.

All good information, but simply testing the injector connection with a ohm meter will only tell you continuity status, it does not tell you if the injector is actually getting a proper pulse signal to inject fuel.
Neither a Fluke meter or an LED test lamp can read the electrical impulses to the injectors fast enough to show you anything while cranking the engine over to start.

That is where the NOID module that you plug into the individual injector connectors shines. It will give you visual indication that the injector is getting a proper pulse signal from the ECM to inject fuel.
Or as Sam stated, an oscilloscope if you are fortunate enough to own one....

Engine Testing Procedures and Fixes, Fuel System wrote:

A fuel injector NOID light will help you to troubleshoot a misfire, No Start or a BAD fuel injector. It is one of those MUST HAVE tools to diagnose the majority of fuel injected vehicles on the road today.

This test will tell you if the computer is pulsing the fuel injectors open when cranking the engine over. Most of the time this test is done when the engine is cranking over but not starting. However, you can do this test when the engine is running. You will be able to see if a certain fuel injector is getting a signal to fire.

All fuel injectors need power and a switching signal from the fuel injection computer. This little tool helps you to visually confirm that the fuel injector is getting both. Now, a fuel injector Noid light test won’t tell you that the fuel injector is BAD, but will confirm that it is getting power and the Switching signal (also known as the fuel injector pulse signal).

Without any of these two signals, the fuel injector will not work.As mentioned before, every make (Ford, Chevrolet, Nissan, etc.) will have a different type of fuel injector connector. So you’ll have to choose the fuel injector Noid light that will easily fit into the fuel injector connector to be tested.

geordi · **Posted:** Mon Aug 27, 2018 1:22 am

Learn something new every day - I may just pick up a set of those noid lights at some point. Electrical issues are a real bugger to solve, but I am still dubious that it is electrics in this case.

The computer should code out as soon as you unplug the injector with the engine running. If it is, then the computer knows that you unplugged something and the problem is not electrical.

Do you have any spare rockers? Did you replace them or just look at them? Did you remove any of them? Here's a dummy test if you don't have any spares and didn't already pull them out and mix them up. It won't cost anything other than labor:

Choose ONE of the two cylinders that you suspect has the problem, and swap all 4 rockers with another cylinder - the #1 is a good option, if only b/c it is right in front of you. Keep them organized - intake to intake and exhaust to exhaust, don't mix them right now. They actually are all the same, but this is for a test.

Now put the top back on and bleed the rail, get it started again. Did the problem move? If yes: Replace all the rockers. If no... Keep investigating. The bearing in the center of each rocker should be solid (not flopping around) and should be RAISED above the sides of the rocker by about 1/16". If not, the bearings have collapsed.

2005 liberty crd UPDATE 9/2/18 Compression results

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