Po 300 ??

[MS2KSE]

Here is as much info as I can give, 2000 with 75,000 miles

About 4 Mo.s ago I stop for lunch, get in and the car runs like it's either running on 2 cylinders or not getting any gas, but there is a heavy gas smell coming from the exhaust, about 3 miles later the car starts running normal.
Last night the same thing happened but this time it stays stuttering all the way home , check engine light come on and stays on. shut the engine off ,it starts and runs fine, took it for a little sprint, no problem all the way to red line, today I took it to Auto Zone and they read the computer thing, he said it shows PO300, "random miss fires" car ran fine there and back ??
any suggestions ?

[tann3r]

Sounds like the infameous dead coil pack. If you drove too far with it sputtering you should expect a P0420 soon as well and are in need of a new cat.

[MS2KSE]

didn't drive over 3 miles with the problem 1st time and 4 miles the 2nd time

[Tom @ Fast Forward]

I agree. Bad coil or coils.

Give me a few days and I might be able to confirm a cheaper and better solution than Miata coils.

[MS2KSE]

thank you, I'll wait to see what you have

[Tom @ Fast Forward]

It'll be here when done.

http://www.fastforwardsuperchargers.com/forum/showthread.php?t=1045

[Gman7007]

I am now suffering from the PO300. She'll start fine most of the time and then the next minute she's stumbling. With the engine running I’ll pull the #1 plug wire and no change. I’ll pull the #2 wire and as soon as I break contact with the plug she starts firing correctly and stays that way until I shut it off.

Should I be shopping for a new set of coils?

(This is the 10AE with a PC-Pro managed MP62 hotside. No timing card.)

Jose

[tann3r]

Am i reading that correctly? It runs better as soon as you remove the #2 spark plug wire?

If thats the case, shoot some die electric grease and see if that cures it. if the wires are more than a year old, they may need to be replaced.

Try gapping your spark plugs down to .025-.030. I was getting an intermittent p0300 and dropping the spark plug gap seems to have stopped it.

Unfortunately i tried this after i sprung for new oem coils and NGK plug wires and plugs...as well as the boundary engineering coils.

Hope your fix costs less than mine did.

[Gman7007]

Plug wires are young, plugs are Iridium so I do not want to mess with the gap. I finally put some dielectric in all boots and it seems to have cured the problem for now.

However, the dreaded P0420 now pops! Guess a new cat is on my Christmas list.

[Gman7007]

Read the coil out today. All readings within spec. Would die electric grease make that much of a difference?

Jose

[tann3r]

Die electric grease is good stuff. I use it on both the coil side as wells as the spark plug side of the spark plug wires.

[Gman7007]

As did I now. Plus the electrical connector on the coil.....after I did the readings.

[Gman7007]

Santa brought me a RoadsterSport Midpipe and Hi-Flow Cat......installed it yesterday and the car runs great!