Jeep 2.7crd not starting
 

Hi guys ive recently purchased a 2002 jeep grand cherokee laredo 2.7 crd got it for cheap as it was in limp mode due to gearbox conductor plate fixed the conductor plate and reset the codes happy days
One morning it started and died so ive read about air leaks so changed the plastic lines and o rings all new the diesel filter aswell next morning theres an diesel leak at the high pressure pump order the kit did the pump happy days again
Drove about 800km filled the tank up and its leaking drove home no issues just the leak pulled the tank out years of crap cleaned off and found the big nut was loose that kept the float inside ..next step is to get air out after tank removal ..primed the system thru with a facet electric pump before the filter ..hard to start drove it a while so it can prime and bleed
Next trip was about 500km to do and started the jeep again difficult to start drove off no hassles no error codes got back and started looking for the trouble of hard starting found the glow plugs not working tested the fuses one is blown replaced it tested relays 4 of the 5 was dead as a door knob ..broken off while attemting to remove while cold not good ..took head of and removed broken bits found small cracks in between valves had the head checked out no leaks got the head welded and machined all valves done put the head back on new gaskets and bolts
Try to start but its not starting tried quick start spray started first time let it idle a while checked for leaks everything is good drove it a few kms came home switch it off let it sit for 30min checked coolant and oil level all is good ..tried to start nothing just cranking ..got the quick start spray and started right away went to drive it nothing suspicious when in 3rd gear gave it some gas floored it it just cut out engine light on pulled the obdii scanner checked it out it shows small leakage detected ..got home removed the injectors send it to bosch to test all of them are wasted? Bought a set new ones installed with new seals and bolts try to start nothing just cranking sprayed quick start it fires up first time
Took it for a drive floored it uphil and same thing again engine light on error code back on says leakage detected ..swopped the feul rail pressure solenoid with new one still the same hard to start and when driving it cuts out when floored uphill
Anything ive missed with this lady
Most of what gives problems on them i have changed and fitted new?
Any help advice?


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Symptoms point to injectors leaking back and not letting rail pressure build at start.
New injectors so I would be looking at pump again. :(

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Frankly, you've replaced just about all there is to replace! I went down a similar road with the transfer case sensor only to find the new sensor was faulty. I'd suggest that you start again with the basics and don't assume that because a part is new it is okay:

1/ Do a leak back test on the injectors.
2/ Start monitoring fuel rail actual pressure Vs set point.

You mentioned checking for codes via OBD. What tool/software? Most generic tools (including Torque app) will miss error codes on the 2.7 CRD. It's not true OBD. You need a DRB-III tool or the software from jeepswj.com.

Im using the software from kaido to check codes and this code is the only one coming up ..what bothers me is that with new injectors its doing the same thing as with the old ones ..how do one go about checking rail pressure?
https://uploads.tapatalk-cdn.com/201...89b7ebac9c.jpghttps://uploads.tapatalk-cdn.com/201...a333ed1016.jpg

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Your second screen shot has it. That pressure is way too low. It should be well over 200 bar at idle.

So i should test injectors and pump the pump has about 1000km since rebuild

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Low pressure can be either a leaking injector, the HP pump, the regulation valve or the sensor.

I'd start with an injector leak test. It's an easy test.

What i found is that the high pressure pump return line that goes on the back of the rail has a flow of diesel as if its just pumping diesel to the return ..i must still check injector back leak ..what made me worry is that with the back leak test it says to blank off the small pipe otherwise it will suck in air
I have to blank it off otherwise i get diesel sprayed ..thats when I unclipped the h/p pump return and saw its the one pumping the diesel out

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Were the new injectors "new" or reconditioned?

If reconditioned, they could be faulty, a leakback test will give you an idea.

Also injector classification may create some issues, as well as a bad fuel pressure regulator.

Jason

As stated new otherwise would say reconditioned ..the injectors are programmed to their specific cylinders
One thing troubles me is that theres so much pressure from the hp pump return doesnt make sense
Anybody got a diagram for the fuel line routing I was told by MB agent that the pipes are in the wrong way ive searched for a schematic layout of the pipes just to correct myself but nothing shows up

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Can't help with a schematic, sorry.

The return line from the back of the fuel rail is the output from the regulating valve. The valve opens just enough that the rail pressure is at the set point and the excess fuel (output by the HP pump) returns to the LP side.

The injector leak (from the tops of the injectors) goes to the fuel return valve on top of the filter. The other line on this valve goes back to the tank. When the fuel is cold, the fuel return valve puts the leakage back into the filter, unless it senses air. If it senses air OR when the fuel is warm, it returns to the tank. This system does not seem to give problems often, but that valve can fail.

If you are seeing lots of fuel in the line from the regulating valve, it *hints* that the pump might be good. Check the regulating valve. It is a fairly common point of failure.

I found these so farhttps://uploads.tapatalk-cdn.com/201...87e7e2a8db.jpghttps://uploads.tapatalk-cdn.com/201...d3ad410736.jpghttps://uploads.tapatalk-cdn.com/201...15dd68f9a4.jpg

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I went ahead and tested these new injectors did the leak off test nr5 injector has very little leak off nr 4 2 and 1 has the same amount but 3 is the highest..im not feeling well with the result as these are new https://uploads.tapatalk-cdn.com/201...3a5b8d2d64.jpghttps://uploads.tapatalk-cdn.com/201...5d613183b8.jpghttps://uploads.tapatalk-cdn.com/201...501975b7e2.jpghttps://uploads.tapatalk-cdn.com/201...8fcddaa940.jpghttps://uploads.tapatalk-cdn.com/201...7c5ee417c2.jpg

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How long did you run the test for?

Did the test running the motor for 1 minute


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I went ahead and connected the compressor gauge to one of the injector lines so disconnected nr1 pipe and cranked the motor to see what pressure builds up my gauge has a max of 12bar reading (so it would be stupid i know as these rails have 300 -1600 bar) i cranked the motor for 10 seconds and the gauge only went up to 6bar and stayed there so ran it again for 10 seconds same story ..very very low pressure

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Gallon of petrol needed and matches will be a good solution

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The injector classification is done problem still persist

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Got a gauge to measure the rail pressure gauge only reads to 200bar but on crank it takes a while to build up pressure when the engine is not turning the pressure drops at a steady rate not keeping the rail pressure is a concern ..

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It does go to max on this gauge but after 5sec on the starter if you wait 10sec theres no pressure if you crank again it must buil up from 0 pressure again

Pressure going down when the engine is not running is normal. How long is "a while" to build up to 200 bar? Mine takes about one second (or slightly less) of cranking to fire, which is 250 bar. It certainly is not instant. This is normal. If it is 3 or 4 seconds (or more) then there is a problem.

For sure 3 to 5 seconds not 1 or 2

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Im going to take the high pressure pump off and send it to bosch and have it tested ..will see what happens

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If you have it running, stop it and try a restart straight away (say within 10 seconds of fully stopping) does it start quicker? If so, you probably have a slow air leak between the tank and the LP pump.

Another cheap & easy check is to install a non-return (check) valve in the rubber line between the filter and the steel line from the tank.

Have you replace the fuel pressure regulator at all?

The injector leak back results look OK to me but they could be confusing the pressure regulator too, does the car run well in the return line in disconnected?

Jason

It can run for an hour if i switch it off and try to start again nothing cranks forever until i spray quick start

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New regulator from mb ..havent disconnected the return while engine is running

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I have started it yesterday engine was cold its making a grunting effect when idling grunt grunt grunt ..like its loosing pressure the pump has 12month gaurantee from july last year so will send it monday back to bosch to have tested will ask if they can test the fuel regulator aswell

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I sympathise with your plight - my CRD is off the mechanic on the 14th to see why it stopped mid-flight. Hopefully it is something as simple as air in the lines.

Attached is a link to a You Tube video I think you might find interesting. (There is a photo of the Grand Cherokee, but I think it is the 2.5l Cherokee.)

I love how the Jeep stealership wanted to replace the engine!

It just shows how hard it is to diagnose problems with these CRDs.

There are other videos on this channel which you might also find interesting.


Enjoy!

The jeep has been standing since august last year did alot of things and still standing ..getting tired frustrated irratated confused etc...

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Thats another thing to consider..ill check it out thanks

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Galloping idle at cold could also mean a bad fuel pressure regulator.

After a long time the high pressure pump was changed the low pressure pump changed a new crank sensor installed and stil it just cranks.. no start issue still ..when givin quick start it starts and run smooth the diagnostics doesnt show any malfunction in the system ..this is realy a strange vehicle

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It could be an injector (or two) with high leak back volume which could create a problem for the fuel pressure regulator, or the fuel pressure regulator could be shagged.

New injectors new regulator ..the jeep is standing since august all the stuff on the engine has been changed the dieselpump was the last thing to be replaced new ..to no avail still not starting

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sounds like you have a problem getting power to the injectors. Does it start with easy start" ?

First shot then it runs

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ok, so if you start it with easystart, then it runs good? and if you stop it and try to restart it when hot??

Can drive it as far as i want ..but switch it off and try start it needs easy start again doesnt matter what temp its at

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No problems runs and drives normal no error codes nothing switch it off and 1 sec later try to start nothing its like the ecu does not pick up im trying to start it

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I went back through this thread and I couldn't see if you had monitored fuel rail pressure while attempting to start. Have you done this? It can give a clue where to start looking.

The other thing to monitor is ECU voltage when cranking.