13brv3

Holler Good Southern boy I guess I'll catch up with you when my current crisis subsides.

Thanks,

Wade

iTrader: (1)

I repeat... you shouldn't need an amp with a stock car and stock computer... fix the cause of the problem, don't band-aid it.

Wade

13brv3

Right you are Wade. After looking closer at some of those "amp" posts, I noticed that they were fixing problems in heavily modded cars. With that in mind, I decided to take the expensive road, and ordered new coils and an ignition harness from Mazdaformance. FWIW, the leading coil was $117, the training coils were $107 each, and the harness was $57.

Also for the record, I do very much appreciate the offer to test those parts Danny. From what I can tell, the stock coils will be fine for the level of modification that I'll eventually have, so I figured it would be a good idea to start with fresh coils now, even if that doesn't fix my current problem.

With any luck, I'll get the coils and harness installed in the next week, and I'll be sure and post an update when I'm done.

Thanks,

spooledUP7

Rusty,
I have toasted two leading coils in my time, and neither time did they act like you are describing. Bad coils limit the amount of power, and the car basically runs very rough. I destroyed my coils by using the Jacobs pack amplifier. The coils cannot handle the extra heat. If they are bad, you will see a bulge on leading coil, and lower than 13-16K ohm between the plug wire holes.

I recently finished my full non-sequential mod, and I have noticed the some break up if I hold the throttle about 50-90%, but not at WOT. My guess is that the computer is trying to manage a stock environment on a modified car. O2 readings are probably dancing all around, and the computer freaks out. The computer goes from open loop to closed loop when going to WOT, so there are no adjustments that the computer is considering, just a set map.
If I were you, I would try replacing your O2 sensor beofre the coils. I would have also check the coils before ordering new ones.

13brv3

Thanks for the comments. Unfortunately, there are several directions I could go with this, which has been my dilemma all along. Since my problem is at WOT, and the O2 isn't supposed to be in the picture, I just have to believe it's something else. We'll see.

As for buying new coils, I think it's a good investment. I'm also on a rotary engine aircraft list, and we have some very experienced racers on there. Recently, one of them went on a tirade about how stupid it was to put the coils in such a hot location. He claimed that it has a very negative effect on the coil life. I figure mine have been cooking at 250 degrees for more than 1500 hours now, so they're well done

Cheers,

13brv3

I installed the new coils and ignition harness last weekend, and also found (I hope) my intermittent boost problem. UPS brought me a new turbo control solenoid, this afternoon, and I was able to get the car back together for a quick test this evening. FWIW, the coils looked fine, and tested OK via the resistance checks that the manual calls out.

The good news is that the hesitation problem is much better, and it may even be completely gone. I still feel a little erratic pulsation, but it was pretty windy, so that may be all it was. Heck, the seq turbo system even worked! It's been intermittent recently, so I'll have to see it work about 5 days straight before I really believe it.

Now I guess I'll have to start thinking about fixing my leaky motor mount. Yuck

Thanks again for all the comments!

LongRX7

iTrader: (12)

Sorry, don't check here too often. But is the ignition pak, hooked up to the stock coils. Once installed on my car, I didn't have anymore high rpm misses. Just my opinion. Your mileage and mine might differ. Plus, I run 9's (sparkplugs) all the way around.

Wade

iTrader: (1)

Pretty good price on the coils. If you haven't already, you might check your fuel pressure. If you have changed your ign harness, the coils, plugs, and wires, and still get the hesitation, I'm not sure what it could be. Could be a bad plug or wire, or some sort of fuel problem. If you have elevated fuel pressure (seems unlikely but possible) you could be running richer than normal, causing the hesitation. Let us know if it is really still hesitating or not.

Wade

13brv3

Good suggestion on the fuel pressure, though I agree that it seems unlikely that it would be high on the stock pump. Of course it was also cold (60= cold for FL) yesterday, so that might have given me a leaner mixture than I've had before. I'll try to post an update when I decide if it's really fixed. Either way, I have to get back to the plane.

Thanks,

Mr rx-7 tt

iTrader: (5)

See if the computer is spitting out a code...It also may be a bad presure sensor...(boost sensor)

13brv3

No codes in the computer, and I looked into checking the pressure sensor, though never did it. I'll make a note to look at that.

Thanks,

13brv3

I just got another change to test the car, and I'm pleased to report that it's strong and smooth now. What I felt the other day must have been the gusty wind.

Bottom line is that it may have been the coils (old ones test OK with a meter), or the ignition harness. I also changed the turbo control solenoid at the same time, but that shouldn't have had any effect. Of course I tested it today on the way back from having REAL tires installed (245/45/16 Bridgestone S-03's), so maybe it was the tires

PS- the guys at Goodyear had a good laugh about the "Grand Spirit- Aqua Flow GTS" tires that were on the car when I got it a couple months ago. They still had about half the tread, but man did they suck.

Thanks again,