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Cat Man
Cat Man, Caterpillar Engine Expert
Category: Heavy Equipment
Satisfied Customers: 8764
Experience:  23 Years Caterpillar Engine experience.
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PETERBILT 379 I HAVE CAT ENGINE,SERIAL NUMBER HBN05932 WITH

Resolved Question:

I HAVE CAT ENGINE,SERIAL NUMBER HBN05932 WITH A NO START,ECM CHECKED GOOD,HAS GOOD FUEL PRESSURE BUT WILL NOT START,RUNS ON STARTING FLUID, AND ECM HAS POWER GOING TO IT,NO CODES PRESENT.
Submitted: 5 years ago.
Category: Heavy Equipment
Expert:  Cat Man replied 5 years ago.

Hi. Thanks for using JA! I will try and help you out. I would like to ask you a few questions first, this helps me help you better.

 

 

 

Does the engine smoke or hit at all when you crank it?

 

 

Does the check engine light come on and then go off when you turn the key to the on position?

 

When you say the engine has plenty of fuel pressure, how much did it have?

 

And lastly, how was the ECM checked?

Customer: replied 5 years ago.

Q1 . NO Q2. YES Q3 PUMPS FUEL OUT OF RETURN WHEN CRANKING, Q4.SENT ECM TO DEALERSHIP AND HAD IT CHECKED.

Expert:  Cat Man replied 5 years ago.

Thanks for the information.

 

If the light is coming on, the ECM is receiving power. Since the ECM was checked at a dealer, I assume it is OK as well.

 

However, I'm not sure if the fuel pressure is good. The reason I say this is because the engine needs at least 40 psi to start. The fuel pressure regulator does not open until 75 psi. The engine cannot build up to 75 psi while cranking. It sounds to me like you may have a failed fuel pressure regulator. You normally do not see fuel coming out of the return unless the regulator has failed.

 

I would advice to install a fuel pressure gauge on the engine and see how much fuel pressure you have. There is a plug right beside the fuel line that runs from the filter base up to the head. This is where you can install a gauge.

 

If your pressure is low, I would recommend replacing the fuel pressure regulator. It is located underneath the filter housing. It is about a 1 inch looking plug.

 

I don't think you have an engine speed timing sensor problem because your engine has 2 sensors. One on the crank and one on the camshaft. The engine can start off just one.

 

Please let me know if you have more questions or need more help.

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