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 Matt Your Own Question

Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 20360
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your Car Question Here...
Matt is online now

My 2003 3.0litre diesel trooper starts from cold but refuses

Resolved Question:

My 2003 3.0litre diesel trooper starts from cold but refuses to start hot. I replaced the oil pressure rail sensor to little avail.l have done the basics...oil and filters, fuel filter, checked for air ingress in fuel system etc. Apparently there is an actuator somewhere that can be a problem. Can you please help?
Submitted: 1 year ago.
Category: Car
Expert:  Shantal-Mod replied 1 year ago.
I'm Shantal and I'm a moderator for this topic.
I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.
I was checking to see if you had already found your answer or if you still need assistance from one of the Professionals.
Please let me know if you wish to continue waiting or if you would like for us to close your question?
Thank you,
Customer: replied 1 year ago.

Dear Chantal. I am still desperate for information about my Isuzu trooper starting problem. Please notify me if your expert needs more info. Thanks in eager anticipation!!! Alan

Expert:  Matt replied 1 year ago.

I'd 1st check the connections to the crankshaft sensor, unplug it and check for corroded contacts and broken wiring, and consider fitting a new sensor - do the same for the cam position sensor

If the EGR valve is stuck open then this too can effect starting so try disconnecting it to see if this helps or changes anything

Could also be an injector leaking fuel back through the overspill pipe, so not getting enough fuel pressure to tell ECU to fire the injectors, this is trickier to find and you’ll need the garage to do a ‘run back’ test to identify which one is the issue

and it may have developed an air leak on the fuel supply pipe from the tank to the engine. The engine has no separate lift pump and relies on the built in one in the injection pump. If a leak has developed on the fuel suction pipe then air entering the system will air lock the pump.
Try pumping up the fuel using the hand pump in the engine bay on the filter housing, then crack off / loosen each injector pipe in turn while cranking the engine and getting an assistant to operate the primer. This will expel air from the injection side and the engine should fire up. The problem will be cured by checking the supply pipe along its length for signs of leakage and repairing any you find.

If you daub each pipe joint with heavy grease and the issue goes away then wipe the grease away one at a time to highlight the problem joint

Customer: replied 1 year ago.

Hi Matt. Thanks for your input. I think the first paragraph is probably the most relevant to me. The other info would be for a more traditional older diesel without the common rail......? I have checked for air leaks. In my experience an engine with failing lift pump or fuel running back to tank is normally difficult to start initially but then easier once the fuel has been got back to the pump purged of air ,becoming difficult again if the vehicle is then left say overnight without the problem being mended. I have the opposite symptoms. Are you specifically referring to the 3.0 litres as fitted to my lsuzu trooper or more generally? Regards, Alan

Expert:  Matt replied 1 year ago.

thanks for the extra information

OK then lets concentrate on the electrical side

This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle pedal position sensor

Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 20360
Experience: BEng hons Mech engineering, in auto industry 22 years
Matt and other Car Specialists are ready to help you

What Customers are Saying:

  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex

Meet The Experts:

  • Greg



    Satisfied Customers:

    Automotive diagnostic tech
< Last | Next >
  • Greg's Avatar



    Satisfied Customers:

    Automotive diagnostic tech
  • Matt's Avatar


    Mechanical Engineer

    Satisfied Customers:

    BEng hons Mech engineering, in auto industry 22 years
  • Ross's Avatar


    Diagnostic and repair technician

    Satisfied Customers:

    Licensed diagnostic and repair technician
  • Rob's Avatar


    ASE Certified Technician

    Satisfied Customers:

    30 years trade experience
  • uk_iaibal's Avatar


    UK Car Mechanic

    Satisfied Customers:

    Verified Car Mechanic.
  • Billy's Avatar


    Trainer/ Master Technician

    Satisfied Customers:

    Trainer 8+ years, master tech. 10+ years, SAE member
  • Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.