P0300 Random Misfire / Primary coil transistor

[eclipseitall]

I've read a few threads where people "semi diagnosed" a P0300 code to be related to the Primary coil transistor to be out of spec. My car throws this code at freeway crusing speeds and I've checked / swaped out most things already without a fix. Now my Primary coil does read high, like 1.1 and 1.2 ohms, and they're suposed to read around 0.80 ohms. So has anyone actually replaced a transistor with my readings and rid themselves of this damn code.

 

[luv2rallye]

Coil primary should be 0.70-0.86 ohms. Coil secondary should be 11.3k-15.3k ohms. That may be your problem.

 

[eclipseitall]

Coil primary should be 0.70-0.86 ohms. Coil secondary should be 11.3k-15.3k ohms. That may be your problem.

Doh! I fixed my above statement. My 2ndry coils do read 11.5K ohms but I just can't believe a difference of less than a quarter ohm would put the primary out of tollerance/order/F'D-up!?!?!?

There were a few threads, which I can't find now for some reason, that people with the readings I got were going to change it out but never replied if it worked...

 

[luv2rallye]

A coil (or anything) out of spec is bad but one within spec doesn't guarantee that's it's good. Some just go bad with age. Things you can do:
1) Replace plugs with NGK BPR6ES (not any other brand - DSM's like this plug best).
2) If you suspect a coil or power transistor try heating them with a heat gun/hair dryer while idling to see if you can force misfires.
3) Pull all plugs. Reattach spark cables, clamp plugs to engine, and watch and compare spark while someone cranks engine. Should be same intensity on all. 1 & 4 are on one coil, 2 & 3 on other.
4) Swap coils/PT with a friend's DSM or buy new/used.
Good luck!

 

[eclipseitall]

4) Swap coils/PT with a friend's DSM or buy new/used.
Good luck!

Thanks, I've done all but the above with no avail, and my stupid bid snipe wasn't set properly to get me a cheap coil set. Anyway I can most likely get someone to do the swap at sometime. It just sucks that there are threads with the info that gets you to a certian point and they never post results...