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I have a 2000 C6500 with a CAT 3126 engine serial #8YL51753,

customer called truck died after...
I have a 2000 C6500 with a CAT 3126 engine serial #8YL51753, customer called truck died after hot run, went up to check truck will start with either, wont idle, changed fuel filter, same thing added fuel got truck running started to drive to shop, the more I drove the worse it got, kept dying like out of fuel, towed to shop no fuel to fuel filter. checked valve on return line seems okay. Pressurized tank still no fuel to engine. How many fuel filters? help please
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Answered in 23 minutes by:
8/9/2016
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
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Thanks for asking your question. I will try and help you out.
Is the check engine light on while the engine is running?
Or no light?
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Customer reply replied 6 years ago
check engine light was blinking while it was dying
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Thanks for the information.
There are many many codes that can cause this.
Does the truck have cruise control switches? If so we can pull the flash codes with them.
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Customer reply replied 6 years ago
the light was not on before that
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Use the following procedure to retrieve the flash codes from the check engine light:
Turn the ignition key switch to the On position/ Engine OFF.
Turn the cruise control ON/OFF switch to the OFF position.
Move the SET/RESUME switch to either position. Hold that position until the yellow lamp begins to flash.
The yellow lamp will flash in order to indicate a two digit flash code and the SET/RESUME switch may be released. The sequence of flashes represents the system diagnostic message. Count the first sequence of flashes in order to determine the first digit of the flash code. After a two second pause, the second sequence of flashes will identify the second digit of the flash code.
Any additional flash codes will follow after a pause. These codes will be displayed in the same manner. Flash Code 55 indicates that No Detected Faults have occurred since the ignition key switch has been turned to the ON position.Let me know what two digit code you get and I can tell you what the problem is.
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Customer reply replied 6 years ago
Rick is hooking up scanner to check for codes, he will probably call you one minute please
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Ok sounds good.
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
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Technician: Cat Man, Cat Engine Expert replied 6 years ago
Phone call session started
Customer reply replied 6 years ago
it has cruise control, and it was scanned with an after market scanner and there are no codes
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Please reply back if you need more help or have more questions. I am happy to assist.
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Customer reply replied 6 years ago
Cannot get any flash codes, there is no fuel to the engine
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Thanks for the information.
I would suspect either the fuel pump on the back of the heui pump has failed. Or the heui pump has failed. It could also be the gear on the front of the heui pump is loose and not even spinning the heui pump.
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Customer reply replied 6 years ago
is there a screen between the fuel pump and the fuel tank,, getting fuel to pump but nothing after thatis there any way you can fax me a detail description of the fuel system or diagram, must be a reason no fuel to filter
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Most trucks do not have a screen.
I'm not sure if I have a diagram. I will check.
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Customer reply replied 6 years ago
thank you if you do(###) ###-####
Technician: Cat Man, Cat Engine Expert replied 6 years ago
You are very welcome my friend. I am happy I could help.
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Customer reply replied 6 years ago
still working on the 3126 cat, does this fuel setup have an electric fuel solenoid.
Technician: Cat Man, Cat Engine Expert replied 6 years ago
No fuel solenoid. Sorry. It only has an injection actuation pressure control valve on the heui pump
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Customer reply replied 6 years ago
I can understand why engine is having issues if high pressure oil is low, can not understand why I have no fuel to fuel filter housing
Technician: Cat Man, Cat Engine Expert replied 6 years ago
the engine is still a crank no start but engine light comes on?
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Customer reply replied 6 years ago
engine light does not come on, only once while driving it to shop engine light started to blink while dying
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Does the yellow check engine light come on with the key in the on position?
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Customer reply replied 6 years ago
no that's why i couldn't get codes
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Thanks for the information.If the yellow check engine light does not come on when the key is turned to the on position and the engine will not start, there are only 2 things that can cause this.The first and most common is the engine ECM is not getting the correct power and ground to function. The ECM should have power on pins 52, 53, and 70 of the rear most ECM connector. This is the truck side harness connector. 70 is the key switch wire. The grounds are on pins 65 and 67. You can remove the connector and check for power on these pins. If you do not have power on these pins, you most likely have a blown fuse in the electrical system. I would check all fuses first.If you do have correct power and ground to the ECM, you most likely have a failed ECM. I have seen this many times over the years. To confirm the ECM is bad, you would need to install a known good ECM on the engine or you can take the ECM to the dealer to be tested. Unfortunately the ECM cannot be repaired. Replacement is the only option. I am sorry. I wish I had better news.Please reply back if you need more help or have more questions. I am happy to assist.
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Customer reply replied 6 years ago
don't forget we drove it, the more we drove the worse it got, going to try to hook up a high pressure oil gauge
Technician: Cat Man, Cat Engine Expert replied 6 years ago
10-4.
So the engine will crank and run?
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Customer reply replied 6 years ago
only with either, its not getting fuel
Technician: Cat Man, Cat Engine Expert replied 6 years ago
The engine light should come on everytime the key is turned on if yours is not. I would check power to the ECM.
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Customer reply replied 6 years ago
the light comes on only for a few seconds it does not stay on, sorry for the misunderstanding
Technician: Cat Man, Cat Engine Expert replied 6 years ago
Thanks for the information.Since the yellow check engine light comes on, this indicates the engine ECM is receiving power and functioning. There are several things that can cause a crank no start on this engine.The first is a low or no fuel pressure condition. The engine needs at least 25 psi to start. If it is low, the injectors will not get filled and it will not start. If the engine has a hand priming pump, and it gets stiff when operating it, the engine has enough pressure to start. If there is no hand priming pump, I would connect a psi gauge and measure the pressure. If the pressure is low, I would change the fuel filters first if you haven’t already. If it is still low, I would suspect a failed fuel pressure regulator on the back of the head or a weak fuel transfer pump. The pump is located on the back of the HEUI pump.Second is a low injection actuation pressure. This is the high pressure oil system that activates the injectors. The engine needs at least 870 psi to start. If it is low, you have either a failed Injection actuation pressure control valve in the HEUI pump, a weak HEUI pump, a high pressure oil leak at an injector, or a faulty Injection actuation pressure sensor. To test the sensor, just unplug it. If the engine starts, the sensor is bad. It has 3 wires and is located on top of the engine near the front and screwed into the head.Third is a failed engine speed timing sensor. Your engine has two. They are located on the driver’s side of the engine on the back of the engines front cover under the HEUI pump. The bottom sensor is the primary start sensor. If it has failed, the engine will be hard to start. The top one is the primary run sensor. They come as a pair.Next is low battery voltage to the ECM while cranking. The ECM must have at least 7.5 volts DC to operate. I have seen weak batteries or a poor connection cause low voltage. You could have a poor connection at the batteries or starter.Next is a faulty engine ECM. The ECM has an injector driver module inside. This is what powers the injectors. If it fails, the ECM will log injector codes for all the injectors.Lastly are worn injectors. Over time the injectors can wear if they have a lot of hours on them. To verify, I like to check AC to the injectors while cranking. You should have between 20-40 AC while cranking. If you do, and you have good fuel pressure, the injectors are worn.Most often when these things are happening there will be diagnostic codes in the ECM. If your engine has cruise control switches, you can pull the codes. If you have never done this, let me know. I can get you the procedure.Please reply back if you need more help or have more questions. I am happy to assist.
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Customer reply replied 6 years ago
we put everything back together, started it with either, ran for a minute then stalled
Technician: Cat Man, Cat Engine Expert replied 6 years ago
You are going to need to have someone read the ECM with Cat Et software. It's the best way to verify the problem.
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Customer reply replied 6 years ago
Can I buy the lift pump separately from the Heui pump?
Technician: Cat Man, Cat Engine Expert replied 6 years ago
you can. Make sure to follow the special procedure to install.
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Customer reply replied 6 years ago
can you send me the special procedure?
Technician: Cat Man, Cat Engine Expert replied 6 years ago
The pump will come with a paper copy of the procedure. Basically it comes with a special shoulder bolt. The heui must be removed and stood up right with the gear facing the floor. If the fuel pump is just removed from the heui. The heui will be damaged.
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