1991 Protege OBD 2 flashes

li Arc

Member
Hey guys,

I have a 91' 1.6 SOHC that was running along just fine last week when I drove off a square curb onto the road (out of a parking lot), which must have jarred something because 5 seconds later as I was speeding off, I suddenly lost engine electricals (it was not gradual, everything just cut). As I coasted along, I tried to re-engage the clutch and see if the engine would re-start or if it would at least sputter or something, indicating some other problem or out of fuel or something, but even after re-engagement there was nothing at all, not even when I tried applying fuel while it was still moving along.

After I had it on the side of the road, I tried to turn the engine over, and the battery was still very strong, but no start. Fuel gauge was low, but not empty (and I've had fuel run out on me before, it does not suddenly cut like that). I checked for spark, nothing on any wire. Nothing seemed to be coming out of the coil neither; I checked the coil, it was slightly out of spec (primary ~ 1.5 ohm, secondary ~12.5kOhm), but again, it wouldn't cause a sudden cut like that. I checked voltage to coil, it was good. I tried swapping both the igniter and the coil, but nothing.

I finally got it towed home, and checked the fuel pump; it was good. After that, I checked the OBD system, it gave me 2 flashes, pause 5s, 2 flashes, pause 5s, etc. So I assume this means code 02, which according to my Haynes, is a distributor Ne signal problem. Somehow we cleared the code, then I went and got me a used dizzy at the junk yard. I replaced it, and after some unsuccessful cranking, I checked the code again and still 02. This time, we thought it might be cabling. Referencing the Haynes manual, pin 2E from the PCM goes directly to the distributor (white-to-white wire), which I assume is some type of crank position or hall effect sensor cable. When checking for continuity, we found this connection was broken. For a quick check, I took the PCM out, and soldered a wire to it and replaced the wire going to the dizzy with it, but this didn't change anything, still no start. I didn't tamper with the wire on the connector, so it's connected in a "Y" configuration right now (the other end being broken between the connector and the cut wire at the distributor end), which I don't know if it may affect the signal or not; I may try pulling the mating pin out of the connector and see.

Other than that, I'm starting to run out of ideas, but I'm quite certain the symptoms point to something electrical. Anyone have suggestions? Thanks!

li Arc
 
Is it blowing out any fuses when you crank it? I had a similar problem in the past (not with a Mazda, though). In that situation, it had to do with my #1 injector wires being clamped under my valve cover, causing a short (don't ever work on a car drunk. It's dumb) But it caused the exact same symptoms as what you are describing. Only thing is every time I would crank the engine, it would blow the injector fuse.
 
Well, I have checked all applicable fuses, and they all seemed fine. I know it's an electrical problem of some sort, but I just can't figure it out.

An update: tried replacing the air flow meter, since a TSB noted that this could be the cause of a no-spark situation, but nothing. I also tried replacing the computer, to no avail, then tried swapping the components around (I think I tried all combinations, just in case it's simultaneous multiple failures), but nothing. I'm starting to wonder if a wiring harness swap is needed; other than that, I've swapped out the entire ignition system plus control system and still nothing, so I've got no more ideas.

li Arc
 
Figured it out. Code 02 does mean no signal from distributor, but in this case there really was no signal. The timing belt snapped, and thus the camshaft wasn't spinning. Originally I thought I did check the belt, but apparently those were accessory belts (which were also in bad shape; timing belt was cracked front and back, no wonder it snapped). This is also why there was no recovery, no intermediacy to the operation, nothing...why the engine just cut like that, which originally felt like an electrical problem.

Remember kids: if you get a code 02, don't start by replacing the dizzy then ripping apart all the wiring...while having someone looking at it, check that the camshaft is spinning by cranking it with the dizzy cap off!

li Arc
 
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