How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Daniel Wilson Your Own Question
Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 7392
Experience:  Owner at DJ Wilson
65405794
Type Your Medium and Heavy Trucks Question Here...
Daniel Wilson is online now
A new question is answered every 9 seconds

We have been trying to fix a problem with our 2003 Kenworth

Customer Question

We have been trying to fix a problem with our 2003 Kenworth Cat c-12 (2KS). Fuel pressure is 80 psi, when we turn truck off, drops immediately. We have replaced fuel return check valve and O-ring, fuel transfer pump and gasket, hand priming pump and gasket, fuel pickup tube and pressure tested the suction side of fuel system. I keep reading your answers about the fuel pressure regulator, seen diagrams, but cannot locate it on the engine.
Currently, we are losing fuel pressure when we turn truck off and still getting air in the system.
Thanks. Doug
Submitted: 11 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 11 months ago.

Hi my name is***** will be glad to help. What are you getting for actual fuel pressure and what codes are logged in the ECM memory?

Customer: replied 11 months ago.
Hi Dan, my fuel pressure at idle is 80psi, 1,000 rpm 85 psi, 1,500 rpm 90psi and 2,100 rpm is 95 psi. I need some help getting the codes from the ECM. The truck does have cruise control.
Expert:  Daniel Wilson replied 11 months ago.

Thanks for the update. Install a clear hose on the suction and return to see if fuel is bleeding back and for air bubbles to look for leaks or restrictions as well. a failed regulator most commonly is the cause of these symptoms and in some cases a faulty transfer pump. Let me know the results. We can follow up as needed.

Customer: replied 11 months ago.
When you say regulator, is that the pressure regulator and if so where would I find this part on my C-12?
Expert:  Daniel Wilson replied 11 months ago.

the regulator is on the back of the head. The fitting the return line connects to.

Expert:  Daniel Wilson replied 11 months ago.

Sorry for the delay. I was away a couple days.

Expert:  Daniel Wilson replied 10 months ago.

Hi, Did you get this resolved? Please take a moment to rate as that is how the site credits my time helping on the site or let me know if you need more help. 5 star and bonuses are always greatly appreciated.

Expert:  Daniel Wilson replied 10 months ago.

Hi, Did you get this resolved? I see this is still open. Please take a moment to rate as that is how the site credits my time helping on the site or let me know if you need more help. 5 star and bonuses are always greatly appreciated. Wish you and yours a great holidays. It's been a pleasure working with you on this.

Expert:  Daniel Wilson replied 9 months ago.

Hello,I see this is still open with no response from you. I am trying to close out my open questions and get them resolved. If you have resolved this please let me know. Im not an employee of the site and my time is valuable as is yours. The site only credits me a portion of the question value on accepted answers and positive feedback. I see neither has happened here. I took the time to post and research this information for you. Could you do the same for me?Take the time to either post a response with a status or leave a rating if your problem is resolved? It's been a pleasure to help.