So here’s the deal. I bought a project car last year (2006 with a purported “blown” motor). They had already pulled the old motor and gave it to me with all the spares and such. I figured it would be educational to tear it apart and see what happened to it. So just got around to it and started with pulling the plugs. Gap is 0.11+”
That seems right. You're supposed to be using these as the coils for it:
Jeeze. The picture didn't post. And it's a 2006 NC Miata motor.
So new plugs and reinstall enough to fire it?
In reply to Patrick (Forum Supporter) :
That could be a challenge.
I just talked to the coils. They all cried out in unison, "AAAHHhHHHAHAaaaaaasssAaaaAAAA!"
I had a guy with an Impala griping about how he'd put plug wires, coils, fuel injectors, a MAF and a used ECM in trying to fix a misfire. I hooked a Tech II up and saw it had a solid misfire on #5. I figured he had done plugs at the same time, so pulled the plug out to do a compression test, saw the gap and my eyes bugged out of my head. Took feeler gages to it and it had a 0.090" gap. Checked 2 or 3 other plugs and they were all 0.075" gap. Told the guy he needed sparkplugs and showed him them and he got a "Boy, do I feel dumb" look on his face.
Stuff like that seems to correlate real strongly with how easy things are to replace. If it were a miata engine the plugs probably would have been one of the first things launched out of the parts cannon. And the harder some plugs are to get to, the more likely the used car you bought has just one or two really old plugs in it with the rest having been replaced!!
I bought two high mileage Vortec 5.7 powered chevies around the same time a while back. Went through both and did all the usual maintenance and checks that I do when I buy vehicles. The first winter, one of them started having cold start issues where it would flood out and then be impossible to start. If I was lucky, I could pull the fuel pump relay and clear it out to eventually get it going. Checked fuel pressure, distributor cap and rotor, replaced the fuel injector spider that is notorious for cracking and leaking fuel into the intake on these, etc. No luck. Eventually pulled the plugs to do a compression test and realized the same thing - massive plug gap, in the 0.1+" range. I went back and checked my logs and sure enough, I wrote down that both trucks got spark plugs. Working on too many vehicles at one time! It has run beautifully ever since.
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