Well, today has been an interesting day. At 7AM, I was on my merry way to columbus to donate plasma. My series 4 RX7 started up just fine, like it normally does. After dropping some gas in at speedway across from Meijer in Lancaster, where I live, I continued on. When I hit Carroll on Rt 33, my interior lights started to dim, but the voltage gauge held steady at 12.6v. Since I replaced my s4 alternator with a FD one (with appropriate pulley), I've noticed some fluctuation, so I dismissed it and kept going. By Pickerington road, it had dropped to 10 volts and was continuing to drop. That's when I looked for the nearest spot to turn around and head home. That spot was the Diley rd/Hill rd exit ramp. At the top, my RX7 died on me, the voltage gauge unresponsive when cranked and the starter acting appropriately.

When I popped the hood, I saw what had happened. My alternator belt had snapped, with a very clean break in it. The other belt (either AC or air pump, can't remember) that passes near the alternator was hanging limply as well.

As my cell service was shut off (family issue, don't ask), I was stuck there untill a nice gentleman stopped and let me use his cell phone to call AAA. After a little trouble on their end about finding where I was (explaned it 3 times), they finally got it in as being in Canal Winchester and got a truck on the way. Thanking my fellow motorist for their kindness, I went back to my 7 and sat inside with the heat on, as the engine had retained some heat. Eyeing the voltage gauge, it was now reading 11 volts. On a whim, I killed the heater and cranked it.

It started up on the first try. Not thinking twice (I only had AAA basic and $2 on me!), I put it in gear, crossed the overpass and headed home. Now, mind you, this is with no alternator power and a very dead battery. The car ran! It ran, getting me as far as Meijer in Lancaster, a sizeable distance of at least 10 miles. At Collins Rd, it died when I slowed down. Fortunately, a nice pair of ladies gave me a jump and it started again! With them following me, I went down Collins rd. slowed as little as possible to mostly-normally turn left onto Fair Ave and kept on untill I hit Becks **** Rd, where it conked out. We tried jumping it again, but no such luck this time. As my house wasn't too far away, they gave me a ride home.

Calling AAA at home, I explained the situation to the same girl I talked to before. She then put me on hold, asking her supervisor what to do. Thankfully, they took pity on me and sent a tow truck out again. Grabbing my mom's keys, I met them where my FC lay defeated. The driver, Ed, sure got a laugh out of my story, and I promptly got my car towed home, at 9AM.

I'm no engineer, but how can an engine start, much less run with no spark? My FC must have a TON of heart.

 

rx7s never let u down

 

There is always spark as long as the ECU is energized. At about 10v is when the ECU will shut off hence leaving you on the side of the road.

The battery does build a little charge after a while, I call it a reserve but im sure there is a better reason why this happends. Something to do with how acidic the acid in the battery is at the time I think.

How long this litter charge will last is dependent on the size of the battery.

Interesting story I must say

 

Stick with the s5 alternator, I had nothing but problems with my FD alternator that I got from silverrotor back when he was selling brand new units. And your voltage gauge should read in the 13.6 range, not 12.6.

 

question, your alt belt runs also runs your water pump. How long did you drive with the belt snapped. I had a situation where I had no belt to run on, and had to drive a good distance to make it home. I had no gauges to read my temps but Im pretty sure I was running wicked hot. I think it being 20 F outside helped.