Wont Start!

[Boyes95]

Hi I'm new to this forum so be gently. I have a chrysler 2003 2.5 diesel 2 weeks ago the rear filter pump failed.so I changed that and now have fuel to engine then fuel rail release valve packed up so changed that now she running lovely but she won't start on her own.ive took pipes of front diesel pump and replaced them and them she starts first time every time til I drive her for half hour then she won't start again.please help this is really getting to me know as due to go away in 3 week time

[mikebh8]

Hi, welcome.

I'm guessing a leaking injector.

After driving the half hour..won't start in that minute or after a while left with the engine off?

Starts first time every time as in every morning starts fine but after driving it, with the engine worm, it won't start again?

[Boyes95]

Hi thank you for your replay.when I turn her off and then try starting her straight back up she won't start? Unless I give her a spray then she will run perfect til I turn her of?

[mikebh8]

It sounds like a leak in the fuel system.

Was doing that to me when I had a bad injector.

Some say a car should start with three injectors too, on this model not so true, at times I was draining the battery and still won't start until as you say I was helping it with easy start.

Remove the return pipes from the injectors, fill the small holes of the top of the injectors with fuel and leave it over night. If one or more it does not have the fuel in it means it leaks.

Other if you are more confident, improvise four disposable coups with the return pipes attached inside the coups, isolate the return lines (should be two) and turn on the engine, after few minutes you should get more or less the same amount of fuel in each coup. There are videos on you tube with how it's done as well.

Hope it helps.

[Boyes95]

Thank you for your advice.today I disconnected fuel line from tank a pressurised the fuel system with air and found a leak on push fit pipe. So changed it and left it pressurised for half hour and it hadn't moved.so far so good as starting hopefully that's the end of the headache.but once again thank you.

[mikebh8]

Happy it worked, let me know (all of us for that matter) if that was it.

Cheers.

[Boyes95]

Little update pressurised fuel line again today double checking.replaced two pipes as wasn't sure if they are leaking.and put non return valve in on flow pipe and guess what still struggling to start if you push accelerator pedal that seem to help fire.i given up on this now all the years I've spent working on cars this one has beaten me.

[mikebh8]

Don't give up so easily.

I end up buying another car after a "new" second engine was already fitted on the car. It finally started it but after almost a year.

Move on to the injectors and see if they're all good.

Good luck.

[Boyes95]

Thank you for your reply I tested injectors today 3 are around same mark and one is not giving hardly anything.going to see if I can get pump test as well tomorrow.could anyone explain how these chrysler fuel pressure works. If one injector isn't returning would that cause the low fuel pressure?

[mikebh8]

"Over night" or when the car is left off for a long time, the high pressure system should be a closed circuit(with no fuel drainage), it is not the same pressure as when the engine is running but when the engine is turned over the high pressure pump will push fuel in the fuel rail system and soon as the pressure riches the right volume (depending on the engine is different) it will open the injectors

If there is a leak the pressure Wil drop and the fuel rail pressure sensor will detect it and it won't give signal to the high pressure pump which won't give signal to the injectors. When easy start is used, the explosion inside the combustion chamber will open the injectors "manually" or forced and more fuel will be pushed in and so the four stages being complete, the engine will run.

From the pump to the injectors is always high pressure when the engine is cranked hence why when working on it it is always recommended to open the pressure release valve, to release any built up pressure, If an injector(or more), or a leak is anywhere along the system, the ecu (using one of the sensors) will send the engine into limp mode to protect the function of it and the parts that can get damaged from the fault.

On mine, when diagnose software was connected to the car's ecu, fuel fault was displayed. I don't remember exactly but was code 42 ( with delphi) and related to fuel level open circuit.

 

Mind that in my attempt to start the engine, the ASD (auto shut down relay) became faulty, that relay interacts with car's immobiliser, high pressure pump and power to the injectors (worth testing it).

 

Having an injector that does not send back the same amount of fuel as the others due, (to me) indicates that it lets the fuel going into the combustion chamber, you probably have black smoke coming out of the exhaust.

Also bear in mind the system used on these cars is "common rail" which indicates that a fault developed on one injector will affect the whole system, these cars also need a very very good battery, otherwise it won't start after work has been done on the fuel system. A wornish battery will work on a daily basis but I had to buy a new one to finally get it started.

Hope it helps

Edited June 19, 2017 by mikebh8

[Boyes95]

Ok found the fault 3 injectors was knackered! So went and replace all 4 today also changed engine oil and filter as I think diesel been leaking.pressured system and hoary it alive! Thank you all for your help much appreciated.

[mikebh8]

Hi, happy to hear is sorted, please mark it as answered for future viewers.