SpeedracerRX7

Ok if you don't want the back story skip the first paragraph. I was at a trackday at VIR when after my first run the car had trouble idling after a session. When I started it I noticed that I needed to feed it some gas to get it to ramp up to idle. Of course the car was low on power until the turbo spooled but it didn't run bad and I was able to make the 150 miles back to Charlotte. I had decided at the track day that my boost problems with the twins were the straw that broke the camels back so I decided to go single. Well I figured since I was having motor problems I would pull it and rebuild it while doing the swap. At the track day I had the boost somewhere between 8-9 psi and most of the time the car wouldn't transition and I would be running around 6 psi up to about 7.5K RPM. I was thinking that because of doing this the car was running in an area in its fuel map that I had never tuned for and maybe it ran lean and chipped an apex seal.

Yesterday after pulling the motor and it accessories my friend and I turned the motor over with a ratchet and it seemed to have pretty good compression on all faces according to its sound. We had just rebuilt his so we knew what an 1/8" chip in the seal would do to the compression. I was wondering what it was like for an ignition coil to go bad? The car was running extremely rich according to my wideband just after the car lost its idle. I have all the parts to do the rebuild but if I don't need to it would be nice not to. I am going to borrow my friend piston compression tester and test both rotors with and air gun turning the engine just to compare the front and back not for accurate numbers.

All that being said is there anyway to test an ignition coil? If all fails I think my friend is going to let me put my coils on his car to test them but it would also be nice to have a conclusive test to try first.

IRPerformance

iTrader: (41)

Look in the Mazda manual. There is a resistance test. If its out of spec replace it.

Improved FD

when my lead coil went bad, the car fell on its face under any boost at all...and it passed the resistance test btw

I just replaced them all, they had 60k miles on them anyway

IRPerformance

iTrader: (41)

I have had that happen as well. If there are close to being out of spec, replace them. I have a few good extras if you need them. While you're at it throw some good plugs and wires on there. The coils don't go bad that often.

SpeedracerRX7

Does anybody know about how much new coils cost? I would rather air on the side of caution if I won't be spending too much.

IRPerformance

iTrader: (41)

I wanna say almost $270 new retail

Mahjik

iTrader: (1)

New? About $150 each.

http://www.mazdatrix.com/getprice.as...m=18-1000-N3A3
http://www.mazdatrix.com/getprice.as...m=18-1000-N3A1