No Start KOEO Code 15 No Spark Problem Solved

Xounlistedxox

Registered User
Well, I've done all the testing I want to do for today. I've been reading several threads on here, and elsewhere online. I was going to wait to do more testing tomorrow before making this thread, but I figured I might as well pick your guys brains since you know more than I do about this car. I've only had it for a week so far.

1989 SC 5 Speed.

So far my car will crank but not start. No spark was checked with my timing light. Verified timing light works on my Mustang. Tested the yellow wire to the ircm it gets 12v. Checked the brown wire with white stripe on the idle air control valve it also had 12v. Tested the wire on the TPS it shows 0v key on or key off. From what ive read this means the EEC isn't getting power, also leaning toward the ircm. Just had the dis module tested. It passed 5 times in a row. Tested the coil pack and it's all within spec.Obviously this could be caused by other things like the Crank Sensor, Cam Sensor, EEC, and so on.

The fan wouldn't come on at all prior to this problem, so I've been leaning towards the ircm. The car ran and drove fine earlier today other than the fan having to be hot wired of course. I hosed down the under carriage with water earlier today to get the dirt, mud, and spiders off the car. After that I removed the air silencer. I spent very little time hosing under the front of the car, most of the time was spend around the exhaust and rear axle. The car fired up fine once, then I shut if off to go inside for a minute. When I came back out to continue I went to fire it up and it wouldn't fire up. I waited a couple hours and tried again. Same thing it cranks but has no spark. The fuel pump fires up every time. Brand new fuel filter, the fuel rail builds pressure fine.

Thoughts?

Problem Solved. Wound up needing to clean corrosion off of the pins on the coil pack. I did that, then added some dielectric grease to the harness connector. Fires up & runs like it should.
 
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Best guess would be DIS. Unplug one wire from the coil pack just to where you can see. Have someone turn the car over and see if it gets spark. Repeat with every cylinder. My DIS went bad and in turn ruined my coil pack. If you do get spark on all cylinders it would most likely be the crank sensor.
 
Best guess would be DIS. Unplug one wire from the coil pack just to where you can see. Have someone turn the car over and see if it gets spark. Repeat with every cylinder. My DIS went bad and in turn ruined my coil pack. If you do get spark on all cylinders it would most likely be the crank sensor.

Im pretty sure the local auto parts store can test these, so Ill pul it off and take it in
 
Just put the coil pack & dis back on. The car started up, but now cylinders 1,3,&4 have no spark. KOER codes were 12 21 33 77 & 74. 74 is the only new code since getting it started again. I ran the codes before when it was running good & they were 12 21 33 & 77
 
Just put the coil pack & dis back on. The car started up, but now cylinders 1,3,&4 have no spark. KOER codes were 12 21 33 77 & 74. 74 is the only new code since getting it started again. I ran the codes before when it was running good & they were 12 21 33 & 77

If cylinder one isn't firing I know it throws the whole system outta wack. I know 77 is goose test not done properly which it turn would give you the 33 (just my guess) The 12 is the IAC which would not affect spark and neither would the 21. I would recheck all the wiring and make sure spark plugs and wires are good and in the correct order. Then again the title to this thread is Code 15. Does it still give you a code 15? It's hard to tell with such random codes..
 
Grounds on these cars need regular attention, and all the more so when it's been sitting...

I'd start replacing ground cables, including the one from the pass. side motor mount over to the frame, then be sure to put the right compound in the right amount under the DIS, then maybe start adding test grounds, after using your meter to see where things are now. Also be sure the battery is putting out more than 12v. Check the ganged grounds on the header panel behind/near the headlights too.

Also check at least the front/upper barness (DIS/coil/crank sender/cam sensor for damage and corrosion. Clean and apply some dielectric grease as needed. From the photo, things generally look unmolested and just dirty. That bath you gave it underneath could have gotten into any number of connections, so have some compressed air handy to dry those out.

Are any dash lights on when cranking or running?
 
If cylinder one isn't firing I know it throws the whole system outta wack. I know 77 is goose test not done properly which it turn would give you the 33 (just my guess) The 12 is the IAC which would not affect spark and neither would the 21. I would recheck all the wiring and make sure spark plugs and wires are good and in the correct order. Then again the title to this thread is Code 15. Does it still give you a code 15? It's hard to tell with such random codes..

I haven't check the koeo codes again since it started working. I plan on going over everything with a fine tooth comb in time. I have several other vehicles, so each of them have to get their share of maintenance etc
 
Grounds on these cars need regular attention, and all the more so when it's been sitting...

I'd start replacing ground cables, including the one from the pass. side motor mount over to the frame, then be sure to put the right compound in the right amount under the DIS, then maybe start adding test grounds, after using your meter to see where things are now. Also be sure the battery is putting out more than 12v. Check the ganged grounds on the header panel behind/near the headlights too.

Also check at least the front/upper barness (DIS/coil/crank sender/cam sensor for damage and corrosion. Clean and apply some dielectric grease as needed. From the photo, things generally look unmolested and just dirty. That bath you gave it underneath could have gotten into any number of connections, so have some compressed air handy to dry those out.

Are any dash lights on when cranking or running?

Will do. My SRT is the same way. Grounds that aren't 100% make it do all sorts of weird stuff from not running right to windshield wipers randomly coming on.

The only dash lights on while running is the check gauge light. I'm guessing that's because the low fuel indicator is on. No CEL, or up arrow.
 
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