8 replies to this topic

[Justin Fowler]

Trying to figure out what is causing my no spark issue. When I turn the motor over I get no spark coming from my coil wires. I checked the resistance of my coils and got 1.0ohms for my primary and 13.0 ohms for secondaries, when they call for 0.7-0.9 ohms and 11.2-15.0ohms.

How can I check my igniter? What other things do I need to check?

[Mike Asselta]

Did you check all of your grounds and the ignition fuse?

[Race Engineering]

Perhaps its the ECU.

[Randy Thieme]

Did this happen out of the blue or after some work was done to the car? Is the harness securely connected to the coil pack? Could be the ignitor, mine went bad on my '93, but I think they're normally fairly reliable. Please help us understand by expanding on what "no spark" means. What other tests have been done besides wire and coil resistance? Simply not firing could be the result of no fuel or really bad timing. You can buy a little spark testing tool fairly cheap which will let you confirm there really is or is not a spark.

[Justin Fowler]

Grounds and fuses are good, ecu is good.

Car had swapped out ecu's to test if the other was a good working unit, it cranked over but I had no fire. I swapped the ecu's back out and my original ecu couldn't start the car. I tested spark 2 different ways. Coils seem fine, I ran a resistance test and the test was perfect. My ignitor on the other hand didn't test out very well. I ran this test http://forum.miata.n...ad.php?t=201585 and got different results, some terminals didn't even ohm out. I am starting with the ignitor but what else should I be checking? It seems the car french fried something during the short cranking

[Mike Asselta]

The ignitor could be a symptom. We melted a couple before finding a cut-off switch wire that was floating in and out of it's connection. Take the fuse clamshell off (not just the lid) and check that all the wires and connectors are tight underneath, especially to the ignitor fuse. Might not be your issue, but only takes 5 minutes to find out.

I would also check the wires into the ECU connector. They're usually tight, but with all the handling one could break. Put a tester on each?

[Keith Novak]

Look at the pins on the ECU to see if any are bent. Sometimes people do it intentionally to fix a bad connection. That can damage the harness so that when you plug the other ECU back in without a bent pin, the harness that was just pulled out of one wit a bent pin doesn't make a good connection.

[Randy Thieme]

Grounds and fuses are good, ecu is good.

Car had swapped out ecu's to test if the other was a good working unit, it cranked over but I had no fire. I swapped the ecu's back out and my original ecu couldn't start the car. I tested spark 2 different ways. Coils seem fine, I ran a resistance test and the test was perfect. My ignitor on the other hand didn't test out very well. I ran this test http://forum.miata.n...ad.php?t=201585 and got different results, some terminals didn't even ohm out. I am starting with the ignitor but what else should I be checking? It seems the car french fried something during the short cranking

Dang, looks like Keith beat me to the post by 2 minutes. Sometimes if a person feels their ECU is not making good contact to the harness they will put a slight twist on the tiny male tabs in the connector located on the ECU itself. The idea is they'll wedge in tighter into the female ends on the wiring harness. Problem is the female ends can get stretched permanently very easily. Once that happens it's near impossible to get any ECU to work. How do I know? This happened to me when swapping ECUs with one whose prongs had been twisted. If you have the other ECU inspect the small prongs to see if any look twisted. If they are that's your problem. Might was well check any other ECU which has been in the car while at it. If that is the issue the good news is a really good auto-electrician can fix the harness. I wound up taking mine to one here in Oregon and that's how it got fixed. Search the forum too as I think someone also found replacement parts once to fix theirs.

[Justin Fowler]

Ignitor went out! Put the new one in today and fired right up. Thanks everyone for your input