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: Mitsubishi
Satisfied Customers: 44491
Experience:  16 years of experience
2499435
Type Your Mitsubishi Question Here...
Chris (aka- Moose) is online now
A new question is answered every 9 seconds

I have a 2002 montero sport, 3.5L with no spark, Yes, The

Customer Question

I have a 2002 montero sport, 3.5L with no spark
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Yes
JA: Anything else you think the mechanic should know?
Customer: The battery had a dead cell and battery was changed, then noticed the 100 amp fuse was blown
JA: Have you located the fuse box? Do you know the fuse number?
Customer: I did change that fuse already but truck still won't start, it's the main 100 amp fuse in box next to battery
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Mitsubishi Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Mitsubishi
Customer: replied 5 months ago.
Hello
Expert:  Chris (aka- Moose) replied 5 months ago.

Welcome, I'm Chris (aka Moose).

I believe I can help on this concern if you still want or need help after this excessive wait time. This is not an answer to your question.

Customer: replied 5 months ago.
I'd like the help but am going to sleep now, will resume later today. Thanks
Expert:  Chris (aka- Moose) replied 5 months ago.

Lets start with the blue/black wire to the coils and ignition transistor. Is this wire powered with the key on?

Is the black wire to the transistor a good ground?

Do you have a scan tool to see if the computer is getting a signal from the crank sensor?

Customer: replied 5 months ago.
The black wire to coils do have power when key is on. What kind of scan tool are you talking about? I have a multimeter and a cheap OBD II scanner tool that plugs inside car on drivers side.
Expert:  Chris (aka- Moose) replied 5 months ago.

Will your OBD tool show you what sensor inputs to the computer are reading. The tool accesses the computer and then you watch the crank sensor. Then crank the engine to see if the computer is getting this signal.

So far this is going to be a CKP sensor or computer or ignition transistor failure for no spark.

If you're confused on what to do now. You have already been charged the full question value. It's now time to compensate the tech that helped you. The only way I can continue to work here and help customers is by getting rated. If you're not pleased yet or plan not to rate me. Let me know so I can help more, close the post, or opt out. Please let me know if you're pleased with my help.

Thanks Moose.

Customer: replied 5 months ago.
The scanner I have just shows if there are codes but no codes showed up, how can I check the ICM or crank sensor with the multi meter?
Customer: replied 5 months ago.
What tool/scanner do I need to read those readings you suggested?
Expert:  Chris (aka- Moose) replied 5 months ago.

There are thousands of available scan tools. You would just need to research them to find one that fits your needs and see if it can monitor things called PCM/ECM inputs or freeze frame data. If it says those things then it will work.

You can monitor across both wires at the CKP while cranking looking for a AC voltage. This will tell you if the sensor is working but it will not tell you if the sensor is reading right, this test can only confirm, yes its doing something.

Customer: replied 5 months ago.
Are these expensive or something that a DIYselfer can purchase? I'm just not sure what I'm looking for, if you have a link to one to put me on the right track that'll be a big help.
Expert:  Chris (aka- Moose) replied 5 months ago.

They can get expensive. You make a decision based on how much information you want and how often you are going to use it. I have a dealer tool and an aftermarket tool for all makes and models. Mine were around 2000$ each.

This tool would work.

http://www.ebay.com/itm/Bosch-OBD-1300-Engine-Diagnostic-Scan-Tool-BRAND-NEW-FAST-SHIPPING-/172258158919?hash=item281b62e947:g:TG8AAOSwa-dWoBfC&item=172258158919&vxp=mtr

Customer: replied 5 months ago.
When I purchase this how will I continue this conversation, with you or does someone else come on from here? I'm not sure how this is being charged through JustAnswers I thought it was a monthly fee for unlimited questions.
Expert:  Chris (aka- Moose) replied 5 months ago.

You are a subscription customer you can open, ask, converse, and rate as many questions as you need for one fee. This post will time out and close on the 13th if not rated prior. Rating does not close the post. If rated you can still open this post and reply. If a new post is opened you cna request me for other issues or you can get any of the other techs here.

Customer: replied 5 months ago.
Thanks, I'll order this scanner tool to make diagnosing easier, I'm just not sure if this problem is the computer or the ICM, I Ohmed the coils and they seem in spec, so I just want to find out before I start purchasing parts, the tool I'm sure I can use in the future.
Is there a way I can check the ICM or the computer in the mean time while I'm waiting for tool to arrive?
Expert:  Chris (aka- Moose) replied 5 months ago.

A scope is needed to check the ECM to ICM signal. The signal is pulsing power. You can mimic this by connecting a test light to battery positive and tap the test light point to the ICM signal input wires and see if spark is made by the coils. If a wire diagram would help, let me know.

Customer: replied 5 months ago.
it would, I checked the harnesses going to each coil and the reading fluctuated between 9-10.6 but never did go completely off to 0.0, I was reading on a different post that it should go on & off pulsing while turning engine over.
Expert:  Chris (aka- Moose) replied 4 months ago.

Hello again Chris here,

I am contacting you because the post has not been closed out. We have 7 days to get a post rated or it times out. When a post times out, that means its no longer on my active list (you reply I never know it.) You have already paid the fees to get this question answered, but it appears you're not pleased, or need more help.

Let me help some more. Is there anything else you feel I could offer so you would be pleased with my help. I have the option to call you if that would be better.

Thanks Chris

Customer: replied 4 months ago.
Chris I should receive that Bosch tester today so we can continue with the diagnosis. What's the first thing I can check with that tester to see what direction to go, as I said before there were no codes and no check engine light on dash.
Expert:  Chris (aka- Moose) replied 4 months ago.

Thanks for the update. Keep in touch on the results.

Customer: replied 4 months ago.
Chris the Bosch tester didn't come in today, they said by end of day tomorrow, just wondering what can I check while I'm waiting for the tester?
Also when I get the tester what is the first thing I can check to see if the computer is responding or if it is fried?
Expert:  Chris (aka- Moose) replied 4 months ago.

We are stuck at this point till we can see if the computer is getting a crank sensor signal.

Customer: replied 4 months ago.
Okay, will the tester show a reading, like volts or something, or will it just say it's ok?
Expert:  Chris (aka- Moose) replied 4 months ago.

It should show a speed reading in rpms.

Customer: replied 4 months ago.
Just with the engine turning over? How long does it need to crank to get that reading?
Expert:  Chris (aka- Moose) replied 4 months ago.

It should produce a signal within a 10th of a second of the starter engaging and spinning the engine.

Customer: replied 4 months ago.
Okay, I'll let you know as soon as I get that reading, thanks for the patience.
Expert:  Chris (aka- Moose) replied 4 months ago.

Your welcome

Customer: replied 4 months ago.
I got the scan tool and Hooke up but not sure where to find the crank sensor reading, it seems to be communicating with the computer and doesn't have any codes but did a scan of system and showed stuff like O2 sensor etc but I don't see where I can do a live read of the crank sensor, any suggestions?
Customer: replied 4 months ago.
I figured out how to check that, I am getting a rpm reading of 160-180 while cranking engine, is this normal?
Expert:  Chris (aka- Moose) replied 4 months ago.

That is good crank sensor reading. So that leaves the ECM or ICM to blame for no spark. If there is no pulsing power from the ECM to the ICM then the ECM is to blame.

Customer: replied 4 months ago.
Okay how do I check those?
Expert:  Chris (aka- Moose) replied 4 months ago.

A scope is needed to check the ECM to ICM signal. The signal is pulsing power. You can mimic this by connecting a test light to battery positive and tap the test light point to the ICM signal input wires and see if spark is made by the coils. If the mimic makes spark then the ICM is good.

Customer: replied 4 months ago.
I'm not sure I follow you on this, so I connect a test light to the positive terminal of battery then touch the test light to the wires going into the ICM? Then is this done while key is on or cranking the engine over? At this point what would I be looking for a continuous light on or the light going on and off as it pulses the signal to ICM?
Expert:  Chris (aka- Moose) replied 4 months ago.

You do this with the key on and with a spark plug removed and grounded to see if the plug sparks as you tap the test light to the signal wires to the ICM.

Customer: replied 4 months ago.
I am looking at wire diagram but don't see the ICM so I can see what wires are the signal wires, I think there are 6 wires on ICM but I know which to check and don't want to damage anything.
Customer: replied 4 months ago.
Thanks I just saw those on the diagram, what threw me was "Ignition Power Transistor"....so the signal wires are: BLK/YELLO, BLUE and the WHITE in the middle? Do each one of those send a signal to each coil separately?
Sorry for these questions but I appreciate your patience.
Expert:  Chris (aka- Moose) replied 4 months ago.

Yes those colors are correct. Each signal wire signals the transistor and the transistor sends a signal to a coil and that coil fires 2 plugs.

Customer: replied 4 months ago.
Got it, so I'll check this in the a.m. and let you know what I find but just to jump ahead a bit, if I don't get a spark from any of the coils what would that mean? And on the other side if I do get a spark with each what would that represent?
Expert:  Chris (aka- Moose) replied 4 months ago.

No spark bad transistor

Get spark bad ECM

Customer: replied 4 months ago.
Thanks that's what I was wondering. I'll let you know what I find. Btw what time is it where you are?
Expert:  Chris (aka- Moose) replied 4 months ago.

TN 12:44

Customer: replied 4 months ago.
Ok, same as here, I see your up late most of the time also. I'm not by the vehicle right now or I would go check now but I'll let you know what I find out.
Expert:  Chris (aka- Moose) replied 4 months ago.

I am here till about 3am. I log back in around noon for a while then after dinner.