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: 4291
Experience:  Owner at DJ Wilson
Type Your Medium and Heavy Trucks Question Here...
Daniel Wilson is online now
A new question is answered every 9 seconds

My 2000 ISM acts like its starving under heavy load, from

Customer Question

My 2000 ISM acts like its starving for fuel under heavy load, from mainly 1200 RPM and up. Light load, not so much but it's still there. Checked fuel pressure, 120 to 145 psi from idle to full throttle. Checked for restriction, 4" of mercury. Replaced fuel pump to no avail, no change. This started out as a hiccup here and there a month ago to getting worse and worse, now almost steady, but never at an idle. Engine starts good. Now it seems I may only be running at half power, but every now and then it will kick in and take off with full power momentarily. The last few days my oil pressure gauge has been going crazy, from normal to high then to zero followed be the check engine light. It's all over the place, oil level is good and the engine is protected against low oil pressure. Would there be another sensor acting up also, or what's going on here?
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 4 months ago.

Hi Gary, Its Dan. What fault codes do you have logged in the engine ECM? Install a clear hose inline on the suction and then return to check for air bubbles in the suction or return side indicating a leak sucking in air or a restriction. Let me know.

Related Medium and Heavy Trucks Questions