ok, so I got myself a 91 civic that gets no spark. Drove home Friday from school, parked it, and then it never started back up. When I took off the distributor cap, I noticed the ignition coil and contact point on the cap was burned, badly. (pic below) Proceeded to swap out the distributor with one I had laying around to only find out it doesn't get spark. Via the manual I tested both the ignition coil and igniter unit. Both were good. Also replaced the cap.



On the primary winding resistance on the ignition coil I got a resistance of .5-.6 ohms and 11 Kohms on the secondary winding resistance. Both are within factory spec. On the igniter, I get 12v when the ignition on black/yellow wire. Also took it to autozone, and it tested good on their testing unit. Along with that I get 7 ohms resistance on the spark plug wires. Plugs were changed recently and looked fine.

Any ideas what it could be? I know I'm getting fuel as I hear the pump prime and I hear the injectors.

 

Did you test the plug wires, and the igniter?

Are all the under hood fuses good?

Check your grounds.

I'd guess its in the wiring leading to the distributor, or something external to the distributor since you changed it (to a good one I assume)

 

 

looks like you've covered all the bases, and the grounds you mentioned are the main one's i would check.

I know you said you dont have spark but i'll ask a dumb question anyway. Did you pull the spark plugs out to watch them spark? I'm guessing you did but I have to ask.

 

Two ways I checked for spark, grounded a spark plug and plugged in it in wire going to cylinder 1 and also checked via the ignition coil, were I took a screwdriver grounded it and stuck it in the ignition coil.

I'm using this website as a guide, and trying everything it recommends.
http://techauto.awardspace.com/ignition.html

I get .1v -.2v less than battery on the coil plug, and three out of the 4 pins on the igniter. On the fourth pin on the igniter which is connected to a light orange wire, I'm getting 9.6v. I think that light orange wire either goes to the tach or the ecu.

I'm starting to think its a ground issue within the distributor. Everything else seems to check out fine. ECU is getting voltage as I probed a black/yellow connector on the harness and check engine light goes off after a few seconds meaning ecu is functional. Fuses are all ok and the main relay works as injectors and pump are clicking.

 

Did you subtract the internal resistance of your multimeter from the primary coil reading? Click the spark link in my signature.

Have you verified that the timing did not snap?

 

timing belt is good as whenever I crank the engine, the distributor rotor rotates. I'll verify that the timing is correct tomorrow.

 

You'd still have spark even if the mechanical timing were off.

Did you do the primary coil measurement correctly?

 

This has happened twice on my 89 Civic Si it was a bad coil each time. Resistance testing did not seem to be much use on these coils.

 

When done correctly, the resistance tests can be informative. In some cases, a bad coil will test good. But if it tests bad, it's bad.

 

Redid the test, and taking the internal resistance of the multi-meter, I got a reading of .4 ohms on the primary and 11.35 ohms on the secondary.

 

The primary reading is out of spec. I presume the secondary reading was actually 11.35K Ohms. Replace the coil.

 

Sorry for the late delay, I'm finally on spring break and able to work on the car. So I tried a brand new coil I got from my local parts store and also bought a NEC iginiter of ebay just to be on the safe side. Once again I get nothing. It cranks but doesn't start.

Going by this http://techauto.awardspace.com/ignition.html website, I tested the injector harness using a test light. I don't get a blinking light while cranking, but a solid light. I'm guessing I should swap out the ECU and engine harness and go from there. Its very unlikely its the ECU as the CEL turns off after a few seconds having the ignition on and do get a 5v at the TPS.