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 Chris (aka-Moose) Your Own Question

Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Car
Satisfied Customers: 38851
Experience:  16 years of experience
Type Your Car Question Here...
Chris (aka-Moose) is online now
A new question is answered every 9 seconds

Isuzu Trooper LS: I am at a loss here. 94 isuzu trooper, replaced

Customer Question

I am at a loss here. 94 isuzu trooper, replaced engine due to broken timing belt, oil consumption, etc. Went to start engine, will only run if spraying into throttle body, dies if not. Checked for injector pulse with noid light. None of the injector plugs show a pulse which leads me away from the ecm. Swapped wiring harness from original motor, still no start. The only thing I dont have is original crank sensor, but if the crank sensor was bad I wouldnt have spark either, correct?
Submitted: 2 years ago.
Category: Car
Expert:  Chris (aka-Moose) replied 2 years ago.

Hello, I'm Chris. Thanks for visiting Just Answer.


I am sorry you have had to wait so long for the first contact. Sometimes this happens when the question you ask is not detailed enough or its just hard to address online. Many have viewed your post, but have decided to pass.

I will do my best to help you. I have access to many repair sites, so at the least I can provide something to address at least part of your concern if it is not something I can address from memory and experience.

I mainly work in the last half of the day 2pm-midnight cst. , so that is when I do all of my responding.

Once you get an answer, you will be prompted to rate me. You are rating my help, not the website, or answer. If you feel the need to rate negative, please save the rating so I can try again or find someone whom may be able to help better.

Thanks for using our site, we will do all we can to earn your business, again sorry we did not get to you sooner.

X Do you still need help?

X Is there any more information you can add?

X At minimum what do you need to know if I can not address all of your concern?




Customer: replied 2 years ago.

Yes still need help. The only way I can get the car to run is to spray it with carb cleaner. All the forums I have read say try to spray with carb cleaner to see if it runs, but dont say anything about where to go from there if it does run. I have spark and I have fuel pressure to the rail. I checked injector pulse with a noid lighjt and I get nothing which mean my injectors arent firing. Ive read that the crank sensor could be bad but I also found that the crank sensor tells the coils to fire as well so if i have spark that should mean my crank sensor is working. The car was running fine before I swapped the motor.

Expert:  Chris (aka-Moose) replied 2 years ago.
Turn the key on and off and feel the ECM Main relay to see if it is clicking. If the relay is not clicking, remove it and test for power on 2 pins with the key on. If your missing a power, verify the engine fuse under the dash is good and the ECM fuse under the hood. If the relay is operating then verify all ECM powers and grounds are good. If the relay is getting power but not clicking then see if your getting a ground on any of the other terminals at the relay. If that's also good but still no click, then replace the relay. The ECM needs to receive a square wave RPM signal from the ignition module in order to fire the injectors and turn on the fuel pump relay. If all else is testing good, check for this square wave signal on the Yellow/Red wire while cranking the engine. If there is no signal, the ignition module may be faulty.
Customer: replied 2 years ago.

Can I get a wiring diagram that shows that

Customer: replied 2 years ago.

Okay checked ecm fuses and relay and fuel pump relay all have power where they should and click when the key is turned on. I tried putting a different ignition control module in with no success. Any ideas?

Expert:  Chris (aka-Moose) replied 2 years ago.

Are you getting a rpm signal?


Customer: replied 2 years ago.

can I check that with a voltmeter? Also it shows an external resistor on the wiring diagram for the control circuit of the injectors, does it show where thats at? Just thinking if I left that unplugged?

Expert:  Chris (aka-Moose) replied 2 years ago.

None of my diagrams show the resistor location. An analog volt meter can check fr a square wave signal.


JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

  • 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 Elm City, NC
< Previous | Next >
  • 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 Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • 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 Walnut Creek, CA
  • 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!
    Sue Charleston, WV
  • 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 Castleberry, FL
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA

Meet The Experts:

  • Chris (aka-Moose)


    Satisfied Customers:

    16 years of experience
< Last | Next >
  • Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)


    Satisfied Customers:

    16 years of experience
  • Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Auto Service Tech

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
  • Amedee's Avatar


    ASE Master Tech

    Satisfied Customers:

    ASE Master Tech advanced level specialist. Wisconsin certified emissions state inspector
  • Jerry's Avatar


    Master Mechanic

    Satisfied Customers:

    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • Richard's Avatar


    ASE Certified Technician

    Satisfied Customers:

    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes