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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4661
Experience:  Owner at DJ Wilson
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Have a 2000 Freightliner with c12 cat Have lose of power and

Customer Question

Have a 2000 Freightliner with c12 cat
Have lose of power and black smoke
No codes
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 4 months ago.

Hi my name is***** will be glad to try to help. Check for air restrictions and leaks in the turbo boost/intake piping causing low boost as well. Check the turbo for free movement and that is spins freely without drag and no oil leaks are present from the compressor wheel. Let me know

Customer: replied 4 months ago.
No air leaks on piping
No oil in turbo
No fins broke
No drag
Air cooler ck out good
Fuel pressure at 110/120
Expert:  Daniel Wilson replied 4 months ago.

Thanks for the update. Connect Cat ET software and do an injector test and also do a blowby test for low compression. Black smoke is overfueling or unburned fuel. Check the overhead. Possible injector problem or ECM hardware/software issue. Did this occur immediately, after other work done, or progress over time?

Customer: replied 4 months ago.
Injector test good
Blow by test good
Over a 2/3 week period
Customer: replied 4 months ago.
What should boost pressure read at idland at full throttle
Expert:  Daniel Wilson replied 4 months ago.

At idle you wont see much at all but you should expect to see over 25 PSI up to 35 PSI boost. Your fuel pressure should remain steady at 75-90 PSI and not drop under a load. Hook up some guages and monitor on a road test and see what you boost and fuel pressure is actually doing. Let me know

Customer: replied 4 months ago.
Boost is 0 at idle
.4 at full throttle
Fuel pressure 90/120
Expert:  Daniel Wilson replied 4 months ago.

Boost is very low/ non existant.... Either you overlooked a leak in the intake piping or your turbo is no good.

Customer: replied 4 months ago.
Any way to test boost sensor
By om it out
Expert:  Daniel Wilson replied 4 months ago.

2.2 Boost Pressure Sensor

The Boost Pressure Sensor is an absolute pressure sensor measuring intake manifold air pressure. Boost Pressure as displayed by service tools and communicated over the data link is the value obtained by subtracting the atmospheric pressure (as measured by the Atmospheric Pressure Sensor) from the absolute value measured by the Boost Pressure Sensor for all C-10, C-12, C-15 and C-16 engines.The Boost Pressure Sensor can measures pressures from 0 kPa (0 psi) up to 472 kPa (68psi). The sensor is supplied by the ECM with 5 Volts DC.

2.3 Atmospheric Pressure Sensor

The Atmospheric Pressure Sensor is an absolute pressure sensor measuring crankcase pressure. Both the Boost Pressure and Oil Pressure communicated to service tools and over the data link is calculated by subtracting the Atmospheric Pressure Sensor reading.The Atmospheric Pressure Sensor can measure pressures from 0 kPa (0 psi) to 116 kPa (16.8 psi). The sensor is supplied by the ECM with 5 Volts DC

Expert:  Daniel Wilson replied 4 months ago.

You would backprobe to verify 5 volts in and then check voltage return from the sensor for 1-5 volts.

Customer: replied 4 months ago.
Koeo
So orange wire has 5
Green has 1.2
Yellow has 0
Koer
Orange has 4.99
Green 1.4
Yellow .008
Customer: replied 4 months ago.
Put a turbo on
Still same problem
Lose of power and black smoke
Customer: replied 4 months ago.
Still having problems with the Trk
Any other suggestions
Expert:  Daniel Wilson replied 4 months ago.

If you checked boost with a mechanical gauge and got close to 0 idle and full throttle under a load then you either have a bad turbo, large leak in the intake manifold or piping, or exhaust restriction.

Customer: replied 4 months ago.
Ok got boost pressure
After Trk warms up still have loss of power
And black smoke
Customer: replied 4 months ago.
Got anymore ideals for me
Customer: replied 4 months ago.
hello u got any more info for me
Customer: replied 4 months ago.
Not done with truck
So I don't want to rate you yet
Customer: replied 4 months ago.
Still have same problem