Friend of mine Montero. Ran great then suddenly won't start.
It's a 3.0L SOHC.

Replaced transistor/ignitor
Had ECM "repaired".
New coil

Other 2 coils fire
3rd coil does not fire

Each coil shows hot (key on) at each smaller wire to include the coil that doesn't fire.

No other checks performed.

Assuming this is an OBD1. Not familiar with vehicle. My trooper OBD1 diagnostics are performed by reading flashes on instrument panel. His has an ADL to which a scan tool can be plugged into. That's about all I know at this time.

thanks,
shooter

It would start on 2 coils (4 cylinders). Does it sound healthy when cranking? Compression test, spark (you have 4 out of 6), fuel.

According to my friend it cranks well, sounds like it wants to start but I believe he shuts it down before it might actually start. Do the individual coils ground via their mounting screws/bolts? If so I thought of running a wire from a screw to the battery neg post and see what happens. I see no ground wire or anything else to ground the coil except for the attaching screws.

The coil pack has a single power wire coming from the ignition switch (fatter black wire). The coils ground thru the power transistor module, which has 4 power transistors, one for each coil and a fourth as a driver for the tach, engine ecu rpm signal. The power transistors are switched via the ecu to set timing. When the power transistor breaks the ground path of the coil, the coil fires two sparks to two cylinders. Each coil has a bleck with color stripe wire (stripes blue, red, and yellow) that is the ground to the power transistor for that coil. There is a 5pih connector on the PT assy, numbered 1-5 with the catch up. 1-3 are the PT control circuits that switch the PT's. 5 is the tach signal output, 4 is ground. 1-3 and probably 5 should show a pulsing dc signal, probably 5v on 1-3 and 12v on 5, when the engine is cranked. I'd check all the connectors at the PT, ecu, and coil pack for corroded or pushed out/bent pins on the relevant circuits.

Go to mitsubishilinks.com and download the factory service manual for the 92-95 models. The wiring diagram is on page 157 for the 24v 3.0 a/t. The manuals also have a complete troubleshooting tree for no spark and testing procedures.

Post back with results and we'll help you troubleshoot, but it's easier if you have acesss to the manual and diagrams.

I'll do it. Thanks my friend.

Us 'Bama boys gotta stick together...

Downloaded the service and electrical manuals. The Master Troubleshooting section references 16-30 thru 50. I assume that's section 16 page xx. The manual jumps from section 15 to 17.
More info. He told me that recently if he inadvertently touches the gas pedal while starting (when it ran) the idle would be low, the tach might show 2800 rpm and it might clear up as he drove or it might not. Except for this issue, he has a very cherry Montero. Thing looks new and runs/feels great. Visually checked the new transistor and all appeared well. We're in the Smith Lake Area. Where are you? Oh, Flat Creek, Georgia.

Found the following while googleing:"The problem was the timing belt jumped time. one of the cams was not in correct timing and the cam sensor would not let the coil fire at the correct time. The belt looked fine so i did not line up the motor and check the timing at first. A bad cam sensor could also cause this problem. After searching the internet #3 coil not firing seems to be a common problem." Here's the thread in its entirety: http://m.mitsubishiforum.com/forum/showthread.php?t=32970

I was born in Jasper. I watched them build Smith Dam. I can remember going to see Clear Creek Falls before Alabama Power drowned it. My uncle used to strip mine around Sayre, based out of Forestdale. I moved away in 1956, to Florence, but my paternal grandparents lived on Alabama Avenue until the early 70's, and I visited often in the summers.

section 15 is in vol2, the electrical manual, iirc

clear creek falls drowned