Fuel Injection Pressure, temp, flow rate, and etc.

[Dick Simonis]

I sort of following up on some topics that were presented in prior threads relating to this subject.

I've been curious what fuel condition parameters the Silverleaf monitors so I just went out to the coach and looked at anything that could be monitored relating to fuel  Found these conditions and set them to display and scan.

Than I fired up the coach and looked to see what info was being monitored.

Lo and behold, everything was reading except fuel injection pressure with units of MPA.  This read .0 even with some load against the brake.  Is MPA Mega Pascals Absolute???

It's my understanding that the input to the Silverleaf is directly from the Cat ECM.  So, does the ECM monitor injection pressure or not.  If so, is the pressure at the rails or   What should it read at idle up to moderate load.

Thanks for any words of wisdom.

Dick

[LaMonte Monnell]

That's a great question and gonna follow this to get more info, can't ever have too much, or can I?

[Dave Atherton]

Gentleman, with the silver leaf and alladin getting engine information. There is a lot of information that is not provided by these company's because cat is not letting all this information out. Caterpillar
has information that is only available through use of Cat ET computer and Cat SIS ( service information system ) that is not available to the public. Cat ET is used for troubleshooting and
changing engine parameters. There are many people that have thought information would be
very easy to recieve from cat only to find out it not avaible. I also keep posting my thoughts when
someone gets hosed or burn't from a cat dealer, let not burn any bridges some day will need
parts or service from a cat dealer. Dave Atherton Retired Cat Mechanic

[Dick Simonis]

Thanks Dave, are you saying Cat does not allow fuel injector pressure be monitored by a 3rd party??

I will call Silverleaf tomorrow and get their thoughts but I would like to ask others with a Siverleaf to to check and see if you can read the fuel injector pressure.

Now that I now I can read the fuel flow and temp that might be handy although watching the flow rate is a bit unnerving.

[Dave Atherton]

Dick, I really do not know how much information that silver leaf can get from Cat on parameters,
But looks like reading is only general engine functions. I do know when Cat ET is connected to engine ECM, all engine parameters and functions are spelled out in very detailed form pulling information
off engine ECM. I do know that to have Cat ET and Cat tech information being now retired from
Cat a person pays for a license that is not available to the public, this is why there is different levels
of information. Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Dick, back again and I do not want to sound negative about what your doing, however
understanding what pressures and parameters mean to a trained tech will locate problems.
What comes into play fuel pressure, injection pressure, fuel rate control and fuel rate limit.
They all have a meaning and work hand in hand. Fuel injection timing is determined by the
engine ECM inputs from components, fuel injection pressure control from ECM by injection
actuation pressure control valve. In this mix the coolant temp sensor, air temp manifold sensor,
atmosphere pressure sensor and boost pressure sensor. Just reading what injection pressure
and or fuel pressure is meaning less to a untrained person and is something worry about.
The Cat engine has all fail safe in place to derate engine or stop engine and having a silver
Leaf is ok but understanding what is going on with above is something most do not understand
and only causes tension while driving down the road. Dave Atherton Retired Cat Mechanic

[Gerald Farris]

Dick,
The Silverleaf on your coach does not read fuel injection pressure. Therefore, the default reading of O is displayed on the screen.

Gerald

[Edward Buker]

Dick,

The parameters you can measure that indirectly tell you about fuel system and directly about engine performance is turbo boost pressure, HP, and torque. You could either record those values for reference during climbs at higher RPM levels or seek out the specs on your engine if you suspect something is off. While these readings still leave you without a direct measure of fuel pressure they are good indicators of adequate fuel flow rates and direct measures of overall engine performance.

As a driver you just need to glance over and see that those numbers are as they should be when the performance demands are on your engine. 

Later Ed

[Dave Atherton]

Dick and Ed, maybe this will help you, the fuel pressure for Cat C-12 is 78 psi., fuel pressure
for Cat C-9 is 81 psi. Location of test port is on secondary filter base.
Dave Atherton Retired Cat Mechanic

[Dick Simonis]

Thanks guys, the info is appreciated.  I'm going to be interested to watch the fuel flow and temperature when pulling a tough grade.  Not sure what it will tell me but still fun to check.  The fuel temp seems like a useful tool depending on where the measurement is taken, since the injectors are cooled by the excess fuel that could be an indication of....something.

[Edward Buker]

Dave,

Thanks for the fuel pressure info, most likely that will be a measurement that would be done by someone like yourself who has the gauge and the means to measure that parameter. Good to know what the value should be though.

Later Ed