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: 4738
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

Cummins isx lots of actuator problems was originally

Customer Question

Cummins isx lots of actuator problems was originally breaking actuator bolts that hold actuators together. Timing actuator on 123 cylinder . Have replaced 123 injectors by mechanic new relief valves on fuel system have done continuity test from ecm to all actuators. Have had entire fms sty system replaced. Truck has been deleted of egr and dpf. Thought might be program related and has seemed to fix actuators breaking but truck still idles rough. When u place one hand on front timing actuator and one on the rear front 123 timing actuator is not smooth u can feel pulses and surges like almost air or something. I am at my wits end truck has had complete inframe less than 30,000 km on it is a string reliable truck until this. Am tired of shops spending money guessing at the problem. Hope u can help. Economy in Alberta is way down and I need the rig to earn
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 1 year ago.

Hi James my name is***** will be glad to try to help. Is it throwing any codes?

Customer: replied 1 year ago.
None displayed in cab
Expert:  Daniel Wilson replied 1 year ago.

Thanks for the info... The fuel pressure should be between 275 and 325 psi and should not be allowed to rise above 350 unless there is a restriction in the return or if there has been any modifications to the fuel system. When these deletes and upgrades were done was there any modifications to the fuel system?

Customer: replied 1 year ago.
Just ecm tuning originally pdi now some GUY that was recommended from a friend mechanic. Fuel pressure on manual gauge max is 350 psi
Customer: replied 1 year ago.
I installed manual gauge to port by actuators and has check valve so during driving I could see max psi obtained
Customer: replied 1 year ago.
No fuel mods done according to mechanic just ecm tuning
Expert:  Daniel Wilson replied 1 year ago.

What was the max pressure? did the gauge peg?

Expert:  Daniel Wilson replied 1 year ago.

Check the return for restrictions and also inspect the regulator for debris and sticking causing excessive pressure to build

Customer: replied 1 year ago.
350 max psi pegged at during all day use
Customer: replied 1 year ago.
It's 11:20 pm here can I call u in am
Expert:  Daniel Wilson replied 1 year ago.

The spec actually is up to 380 so I would pick up a 600 to 100PSI gauge for testing.... Here is a link I have for fuel pressure checks.... Is for low fuel pressure but still the same principle.

Fuel pressure checks

Expert:  Daniel Wilson replied 1 year ago.

Yes its 1:22 AM here EST and I was logging out as well. Ill send over the phone services link if you would like to call by phone tomorrow.

Expert:  Daniel Wilson replied 1 year ago.

Fuel system information and component locations

Click the link above. Check for restrictions on the return side, through the ECM, and the pressure regulators.

Expert:  Daniel Wilson replied 1 year ago.

Hi James, Did you get this resolved?

Expert:  Daniel Wilson replied 1 year ago.

Hi, did you get this resolved?

Related Medium and Heavy Trucks Questions