Cat C6 Start Problem

[Khein]

Im having a problem with a C6.6 engine. It just stop working, now it crank but wont start. If you add ether to engine it starts right the way and cotinue running without problem.

Im doing all tests and everything point to injectors, but I want to try the high pressure pump as well. Does anyone know how can I try this pump?

Im measuring the ammount of fuel that comes from the high pressure fuel pump to the return circuit, but I dont know what ammount of fuel in normal. Does anyone know this data?

[Mjheavy]

I would look at the Primary Speed sensor first. Try swaping the Primary and Secondary speed sensors, If they are the same part numbers of course. Its easier than doing injectors and a pump.
Whats the engine's ser# ??

[caterpillar01]

Amount of fuel for C6.6 on return line ( injectors ) is 38 mL . That engines had lot of problems with injectors. Do you have any active codes ?

[c16man]

If the desired rail pressure is below 5mpa, check timing sensors.
Think in youre case the injectors is shot. Remove the injector leak off line at the rear left side of the head. plug the line. Remove the three injector harness connectors (rocker box) Get a suitable container and catch the fuel that will be coming out off the head. Cranc the engine if the fuel is more than 38ml in 30 sec, replace injectors. Do the test 3 times, let starter cool after each test.

[c16man]

Also while crancking the engine (before doing leak off test), check the ACTUAL rail pressure (CAT ET), must be 5mpa and more.
Loosen the hp line from the pump to the rail, and cranc engine if fuel comes out, you know that the pump is ok for now, replace injectors.
Remember to replace the hp lines when replacing injectors and DO NOT adjust the valves the conventional way, you will end up dropping a valve, there is a special sequence to adjust valves

[c16man]

Im having a problem with a C6.6 engine. It just stop working, now it crank but wont start. If you add ether to engine it starts right the way and cotinue running without problem.

Im doing all tests and everything point to injectors, but I want to try the high pressure pump as well. Does anyone know how can I try this pump?

Im measuring the ammount of fuel that comes from the high pressure fuel pump to the return circuit, but I dont know what ammount of fuel in normal. Does anyone know this data?
Serial number begins with 666?

[bigwrench]

The drive gear for the pump can loosen, usually will not run at all, but yours could be slipping a little and not building enough pressure at starter RPM, but probably injectors.

[motoraio italiano]

look relife valve on rail, some time is this, do not to do some try with selonoid, burn quicly, ard start is tipycal problem of this engine, we have a lot of higth pressure pump case replace ready, some time is also low battery, and the electronic ECM go in safety, if you have Et or EST diagnostic software better,hope can help you

[Khein]

Thank you for all advices.
Engine serial start with 666. We have ET and now we have done some test.
We have no active codes.
Primary and secondary speed sensors are OK.
Relief valve in fuel rail is OK.
Return from injectors is a lot more than 38 mL, es about 90 mL.
Pressure in fuel rail is also lower than it should be (can this be cause by injectors?).
How can I test if the high pressure fuel pump is working correctly???

We allready have checked how to adjust valves.
If we replace the injectors we should replace the HP lines?

[Khein]

The drive gear for the pump can loosen, usually will not run at all, but yours could be slipping a little and not building enough pressure at starter RPM, but probably injectors.

How can you check this without taking out the pump? Because I think this pump is a problem when you take it out.

[Mjheavy]

You might want to try the dye test. CAT sells a fuel dye that you put a few onces in your fuel filter, then run the engine for a few minutes, then use a black light to see if fuel is leaking past the upper oring on the injector. Which might be causing your non-start problem. Does the engine oil smell like fuel at all? Have you taken an SOS sample to check for fuel dilution?

[c16man]

Well with 90ml per 30 seconds the pump sounds OK.
Replace injectors and their HP lines, after loading the trim files, do a fuel verification test , that will test the pump injectors etc (while engine is running on Cat ET) 90ml leakoff is A LOT. What I usually do to test the pump is (while engine is running and when it can run) to plug the rail pressure sensor out and feel the pressure relief valve pipe it will become warm, that means that the relief valve is opening and pump is delivering max pressure the engine will also be running "harder".
The high pressure lines must be replaced after they have been loosened.(according to CAT it is for safety)
To remove pump you will have to remove fan, water pump.

[Khein]

Thank you for all advises. We replace all 6 injectors and the engine now runs very good. It seems that they were all the problem (danm bad quality diesel).
One last question, in order to remove fuel pump I think I read that you have to mark position because of speed sensors, is that right? How is procedure for this?

[c16man]

Put engine on no 1 tdc compression, on the right side of the engine below the turbo is a plug in the block, remove plug and insert timing pin/bolt the notch is in the crank counter weight. You will also need the 338-1054 pump timing tool to set the hp pump timing.
Drain coolant remove fan, waterpump, remove timing cover, remove HP pump gear and HP pump bolts.
Pay close attention to timing otherwise you will end up with a timing offset fault and then youl have to do it all over again.

[MAXIFLO007]

Hi Guys,

I have a similar problem on a C6.6 engine : there is no flow at all at the oulet of the HP fuel pump but the fuel transfert pressure feeding the HP pump is ok.



This problem happened after a fuel pipe repair on the fuel transfert line (low pressure) between fuel filter and HP pump inlet.

Then, after air bleeding the engine started properly and stoped after about 20 seconds running.

Can anybody advice ?

Do only air remaining in the exchanged pipe can cause a HP pump failure ?