hornetball

iTrader: (4)

Sorry guys. I'm dyslexic (sp?). I could have sworn you said you were running an MS3.

hornetball

iTrader: (4)

Frustrating problem. Just to throw stuff out off the top of my head:

1. Engine cam/crank timing verified.
2. Crank pulley mark verified.
3. Engine ignition timing verified against crank pulley mark.
4. Correct heat range spark plugs installed.
5. Plugs gapped to about .030 (you can open up later once it's running well).
6. Dwell angle correct for COPS.
7. MS ignition map verified (looks similar to other conservative maps -- or use MSPNP base map).
8. MS overboost and rpm limit settings verified.
9. Others???

mellowout

iTrader: (2)

Heres my actual tune if youre curious; worked fine with the stock coils, though.

mellowout

iTrader: (2)

The Toyota coils fire when triggered from 0v to 5v correct? should my spark output be inverted?

edit: I suppose not, since I dont have the special spark-output circuit.

Any other ideas? The pic of my piston looks like it does have some carbon buildup; could this cause hot spots?

mellowout

iTrader: (2)

Also, seems to be misfiring pretty bad when it gets warm under load.

bmxfuel007

iTrader: (21)

have you checked your cops to see if they are firing? I'm not sure about MS1, but there is an output test mode for ms3. I hope you didn't leave your coils connected while upgrading your firmware. I've gone through a few coils because I've forgotten myself, and I realized after the fact. Could be that one or two coils are going intermittent when warm?

mellowout

iTrader: (2)

I havent explicitly checked to see if they are firing, but I am able to run and drive the car, so I dont think the coils are fried. What would cause the coils to go weak when warm/under load?

bmxfuel007

iTrader: (21)

I had perfectly fine coils before, then forgot to unhook them like a good boy when I upgraded my firmware, and the car would start fine, but then would misfire like crazy when I went into any kind of boost. It would only get worse from there as in idle, I'd hear tiny little blips, but the car still ran fine while out of boost. I swapped in an extra set of coils I had and no more problems. It's nice to be able to make a log file, or see my a/f gauge go rich for a split second, and have a test mode to see which coil is dead. I had 2 that eventually completely died

If you do have an output test mode, pull your cops, put plugs in them, and click the test coil option and see if you see them firing. Might be better if you test them after the car is warmed up, hopefully without burning yourself

Could be something is fried on the inside and as it cools, the connection within is fine. As it warms up, things expand, and that connection might be arcing inside? or not making a connection at all? I'm only speculating. Easiest way would be to pull the coils, stick some spark plugs in them so you can see it spark under test mode

mellowout

iTrader: (2)

Those symptoms sound exactly like mine. However, I dont think MS1 has an output test mode. Wonder if theres a way to bench test it without having to crank the car. I assume that my spark would appear normal if I were to just try to crank it and watch the spark.

Sounds shady, but could I just hook a drill up to my CAS, run it, and watch the plugs fire?

hornetball

iTrader: (4)

I don't have COPs on the Miata, but I do on other cars (Ford Expeditions). COPs definitely have reliability issues. I've tried to find bad COPs by ohming with a multi-meter, but always got OK indications. Like bmx said, when they misfire, it is usually temperature related. Only sure way to find them is to swap them out based upon a consistent misfire code -- which doesn't help you much.

You might try buying 1 new COP and swapping it into each of the four positions to see if the situation improves.

This is one of the areas where LS coils are better than COPs.

mellowout

iTrader: (2)

Interesting news: I got a set of new coils in today.

Installed them and reset the base timing, and I had to advance the timing via the CAS to get it to the static 10 degrees BTDC.

Everything seemed well, and I took it out for a test drive. No ping, COPS performed well, even through moderate heat.

Did have spark blowout at 10-12 PSI, though.

Its cooling down right now, but I will shorten the gap on the plugs to see if that will do the trick.

edit: well, ****. it appears BKR7E's are already gapped at .028. Can I get away with less gap?

Braineack

iTrader: (62)

you should be running like .040"-.044" with toyota cops.

mellowout

iTrader: (2)

So you're saying that a bigger gap is the answer?

Or that they should be working fine with the gap I have?


The way I understand it, spark blowout is caused by:

1. Too large of a gap
2. Too rich of fuel mixture
3. Weak ignition
4. Retarded timing

Spark plug gap just seemed like a good place to start.

Braineack

iTrader: (62)

im saying your **** is fubar if you cant run a .040" gap to 20psi.

mellowout

iTrader: (2)

Could the difference be that since I am running a MS1, my dwell should be 2.1 instead of 2.5? About to give this a shot, and report back.

mellowout

iTrader: (2)

Result: Nope, no real noticeable difference. Might end up tightening the gap, then.