KAPOWWWWWWWWWWW!!!


My ears are still ringing. I hope nothing got damaged in this backfire episode.

Rewind since the last posting. So since I made the last posting, I found 1 too many wires that were questionable in quality, location, or on the verge of down right scary. So I went through and rewired the entire car (mostly anyway). I am not an electrical guy by any means, but I think I have it wired properly and in a much better state. Not showroom by any standards though.

Anyway, today I tripped on the ignition switch, fuel pump comes on, all systems are a go. I can't believe it actually worked. I can, but I am a little self doubting sometimes. I also swapped out the Leading coil pack while I was cleaning things up. Upon test firing it, I found that the Leading coils are now firing :icon_tup: . However, during that same test KAPOW!! The loudest backfire I have ever heard come out of this thing occurred.

I put the coil wire back on, let it sit for a bit, grabbed some food, then tried again thinking that maybe there was some fuel left behind causing this sweet sound. So I went to crank it again. After several cranks once again, a rib shaking backfire occurred. What did I do??


So here are some things in troubleshooting that I have done:
1) Replaced the CAS with a spare, but then put the original back in because it did the exact same thing. I "believe" I replaced it correctly see pictures below. It looks oriented the same as compared to pictures of a "Stock" configuration I have seen before.

2) I replaced the Leading coil (used unit). The leading plugs now fire, so that seems to be a good thing.

3) I replaced all of the wiring. I didn't modify the wiring any, just replaced everything that looked bad. It is all pretty much routed the same way as before.

4) The computer was unplugged for a while, but I am pretty sure the program is the same. Some of the few key points I saw showed that it appeared to be the same anyway. I can check that of course.

Any thoughts on this will help.

MaczPayne - I will head over to the West Coast section after this. I can always used an experienced hand. Thanks for the tip.

rx72c - Thanks for the tips. I think I am pretty much exactly where you are at. I think the coil was bad as the new one is now firing. There were wiring issues for sure though. Not sure if they contributed to the problem though.


Thanks
-Sam

Timing is spot on.
backfiring sounds like alot of fuel on crank.
Unflood the engine(get all teh shit out of it with computer disconnected and plugs out of it).
Clean the plugs(preferably get new ones) and it should start.

I will try it again tomorrow. We blew everything out, so I thought, but there might have been some still. The only other thing I am wondering now is if the injectors are leaking. I have to start looking at how to check my injectors or fuel pressure.

-Sam
P.S. anyone else seeing this site run slow? I hope it is temporary. It's hard not to get my rotary fix :)

She's ALIVE!!!


That's right. She fired up today. Here is what I did all together:

1) rewired the poor/neglected wiring
2) replaced the leading coil
3) kept my crank angle sensor in its original location
4) dropped a little ATF into the chambers and cycled it around until it didn't spray much out anymore. I then waiting over night to let it "set in". I then cycled it again to purge out remaining ATF. I saw it here on the board as a trick and verbally from somewhere else. I guess it may help loosen up the apex seals if they are sticking due to carbon or something else.
5) reset my MixTRM to 4% (how it used to run). Though this might not be optimum, I know the vehicle used to run at this setting.
6) reverified wiring :icon_tup:
7) replaced all new plugs with yup you guessed it, new plugs (just because I had them)
8) when I would crank it, if it took more than 2 tries, I turned off fuel and spark and just cranked the motor only until no fuel was left coming out the pipe. Then I tried it again. It took 3 tries like this then fired up!!!


So my conclusion in this story:
1) The leading coil failed on me which may or may not explain why the trailing coil was firing during cranking instead of the leading. Because when I swapped in the leading coil, it fired and the trailing didn't during crank. That of course is an assumption, though I am pretty confident the Leading coil was intermittent in function.

2) The wiring was bad all around and there may have been present or future gremlins to haunt me, so this was a perfect time to touch it up and learn a lot about the rotary.

3) I need some serious tuning. I need to find a good local tuner in my neck of the woods to truly dial it in properly. My blind roll of the dice hack it up guess work on everything can only get me so far.

4) RX7Club.com and the above posting members have been the biggest help in getting it to come back to life. I hope to meet some of you guys at an RX7 get together some day.

Thanks again guys. Lets hope it starts again :ret:

-Sam

Good shit.
Get it tuned now mate.

Or if your gona do it. get it done asap before you kill another set of plugs. Mainly clean the idle out so it dosnt kill the plugs straight away.

The leading coils will fire all the time. The trailings don't fire on crank, but they will when the motor is running. And yep, you should get it tuned asap if you want to keep your plugs clean. My TII isn't tuned yet, and I eat a set every 3-4 weeks.