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Juan Crespo
Juan Crespo, Tech Trainer
Category: Car
Satisfied Customers: 1526
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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I have a 2003 isuzu npr that was running fine. I was going

Customer Question

I have a 2003 isuzu npr that was running fine. I was going down the freeway and it just quit. It will turn over and over but it will not start. I know it is probably a relay but there are so many of them and they are not marked. any help will be appreciated.
Submitted: 1 year ago.
Category: Car
Expert:  rpmdiag replied 1 year ago.

Hi, I’m Ron and I can help you.

I have been in this business since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. I can't see, smell, hear,or touch the vehicle either, so it may take a few replies to get to satisfactory results. Please be patient!

I also try to give all of the information you may need, expecting a “positive rating”in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

Most likely not a relay, but more likely a fuel or spark issue. Can possibly even be a valve timing issue due to a belt or chain. You didn't mention the engine you have for me as of yet. that can help narrow it down.

Thanks, Ron

Customer: replied 1 year ago.
4 cylinder diesel
Expert:  rpmdiag replied 1 year ago.

Thanks, ***** ***** then and concentrate on fuel pressure first. Are you equipped with the tools for these tests?

Thanks, Ron

Customer: replied 1 year ago.
i have the tools for the tests
Expert:  Juan Crespo replied 1 year ago.

Hi there. Different expert here.

Will the engine start if you spray WD40 (please don't use starting fluid) down the air intake?

Customer: replied 1 year ago.
it will start with wd40, what could that mean. sorry it took so long to get back to you.
Expert:  Juan Crespo replied 1 year ago.

Hi again.

If it starts with WD40, then chances are the primer pump on the side of the main diesel injection pump is faulty, or the injection pump itself is contaminated with algae from the tank, or the shutdown solenoid is stuck ON.

Try pumping the primer pump to see is it fills up the filter. Replace the pump if it doesn't.

If the filter is full, disconnect the shutdown solenoid on back of injection pump and try to start the engine. If it starts, check why circuit is on. If it doesn't start, remove the solenoid and retry to start the engine. If it starts, replace the solenoid (manually push the plunger to shut the engine off)

To clean the system and kill the algae, run a couple of gallons of kerosene through it.

Please let me know if there's anything else I can do for you.

Best Regards.

Expert:  Juan Crespo replied 1 year ago.

Hi again. Just checking to see if the information I provided helped you solve your issue. If it did, kindly accept and rate my answer now. If it didn't, please reply.

Best Regards.