BRuth

Hi guys, I just picked up about a month back a 1989 RX-7 FC GXL Non-Turbo, that runs and I am restoring a little bit at a time. I need some advice regarding an issue, which my mechanic cannot solve and I would appreciate if someone could give me a hint to get him in the right direction. Yes I checked the FAQ and if there is a thread that addresses my issue then please feel free to point me there, because I did not find it.

The previous owner was a kid that put a mother of all sound systems and amp in the car, which sucked more power than the poor car could handle. The little &#@! charged the battery to full before taking it to the dealer to be sold and the car started showing power problems as soon as the battery started going down since the alternator had barely enough juice to run the engine with the stereo plugged in. He also did a half-baked job of wiring on the stereo; it was clearly a mess it up yourself project for him. My mechanic checked the alternator and battery and they are fine. Pulled the breaker on the stereo and I will replace it at a later date with hopefully an original or at least an equal to what the car came with.

The problem, which the car will not do in front of the mechanic and he cannot figure out, is this:
Start the car and the power sunroof, wipers and defroster fan are cold dead. Turn the car off and restart it and suddenly they all work again. These problems are hit and miss and turning the car off and restarting it may take several tries before the dead systems will come back on. Once the dead problem hits none of these systems will work until the lucky charm turn off and restart occurs.
Something else that may or may not be related the car will occasionally get “bucking spasms” when driven around or under 10mph. The area where I live requires that I drive that speed before exiting to a main street for a couple of blocks.

Just as general information here is the status of items that are not working and on the list to be repaired or replaced:
Back Window Wiper motor.
Ignition Switch – My mechanic says it has seen better days.
The head light retract system.
Wiper switch – The delay for the wipers indicates it is wearing out.
The clock fades out after start-up and does not keep time.
AC is none functional.

The kid also had installed a ON/OFF kill switch on the middle column that when thrown kills power to everything, I have a gut feeling this does not bode well, but neither my mechanic or I can figure out why he installed such a kill switch where it can be hit by accident easily and it does kill everything including the engine. It has been bypassed.

The kid is in the service and got shipped overseas, so I cannot locate him to figure out his modifications. My mechanic is very qualified in electrical systems, but this one has him buffaloed.

Despite the problems, I have fallen in love with my RX7 and treat her well with the best fuel and checking the oil on a regular bases among the other normal maintenance that I have read about here and in the Chilton manual. She is in good shape, except for the electrical bugaboos and will only need minor repairs to her body and a new coat of paint in the end. She is not getting abused as I average just about 75 to 100 miles a week on her as I live within 10 minutes of the office I work at. I intend to use her for my daily car and for weekend day trips, but those day trips will only happen after the electrical problems are solved.

Thanks in advance for any help.


BRuth

Rx7MPGUY84

probably a problem with the cpu or maybe your grounding is messed up. wait for icemark to help u out. he always awnsers neat questions like this. or pm him. he's lots of help

tmking66

When your electrical systems are not working next time with the car running try turning the key back towards the off position just a tiny bit. Not enough to kill the engine. I have an 88 that does stuff similar to your description and I found that by turning the key back just a hair everything comes on. Probably caused by a worn ignition switch. Its worth a try and at best it solves your mystery and and at worst it doesn't and you are out just a couple of minutes of your time.

Good luck!

OverDriven

You sure your mechanic knows his electronics? Sounds like a simple loose ground to me.

-Joe

hugues

probably a fuel cutoff switch.

hugues-

WAYNE88N/A

Like a couple of people have already said (including your mechanic), sounds like the ignition switch will solve at least some of your problems...All 3 of your "dying" components are on the Ign 2 circuit (I'm using S4 schematics here, gotta assume the S5's are similar, if not, Icemark will jump me )

Try adjusting the Throttle Position Sensor for your "bucking" problems, although rx-7's are famous for this at low speeds...

The clock fading out is most likely a cold solder joint in the warning panel assy...

Icemark can also help you with the wiper switch, in fact I'm sure he'll try to sell you one of his rebuilds first thing

Headlight retractors might be the fuse in the engine bay fuse box, if not, some troubleshooting will be required (yet another "every rx-7 gets this sonner or later problem)

Enjoy the car, you've got all the brainpower you could possibly use on this forum...

BRuth

First all thank all of you for the replies and the useful information.
I had the outage today and tried the suggested jiggle test in the ignition and low and behold the dead arouse from the power grave and worked again. So the ignition switch has made it to the top of the item repair list.
As for my mechanic and the company he works for they are both very qualified and specialize in the electrical systems. We used them often at my last company where we had a large used and abused truck & van fleet when it came to electrical gremlins.
Like a lot of technical problems with any kind of equipment half the battle is getting it to fail in front of the person trying to repair it. My mechanic backed off because he understands I am on a limited budget and did not want to run up my bill tracking the gremlin until he could see the malfunction in action. He just could not make it malfunction and I am never in a position to take it right over to him when it fails.
After reading this group before joining I came to the conclusion that there was enough experience here that someone might do a “AH HA” I know that problem well.
Thank you fellas once again and I hope that I will be able to return your kindness in the future.
As I said, I had a feeling that the mystery kill switch might not bode well. From your brief comment can I assume that like many early cars with fuel injection that there is a possibility in a accident that the fuel pump may not shut off leading to a very ugly and dangerous situation? My late father-in-law had a “panic switch” in one of his trucks because of that problem and that is what came to my mind when I read your response.
If that is the case then I will replace the easily hit rocker switch the kid had with a toggle with a flip cover to prevent accidental shut off. I have no problem for keeping the switch if really has a good purpose.
I will mention your other points to my mechanic the next time I talk to him.
To say the least the wiring under the hood is a mess and many of the breakers/fuses were pulled including the wiring to the flip up motors for the headlights. I think the kid disconnected just about everything he thought he could get by with to get power for his boom box system. To give you an idea of what I am talking about the juice pulled from the system with the stereo and booster in the so-called sleep/off mode was so great that if I turned the headlights on at a stoplight the idling engine would go into spasms trying turn over with the RPM gauge twitching like a cat tail. Pull the breaker on the amp and stereo then repeat the same situation and there is a very slight twitch by the rpm needle and that is about it. The amp gauge stays around 12 almost all the time whether or not the stereo & amp are plugged in. According to my mechanic he has seen a lot of boom box syndrome because people do not understand their vehicles were not set up to carry these heavy power loads in stock configuration, especially older cars. Since I am not into boom box cars, this was my first experience with the problem and probably the last.
So I will check in from time to time, include my restoration tales for your amusement as I get each item on my repair list checked off and make comments when I think I have something useful or constructive to add to a conversation. I will also ask a few questions here and there along the way also.
Thank you for helping and welcoming me to the group

Take care amigos

BRuth

WankelViking

iTrader: (2)

The switch is probably there to switch off the fuel pump to avoid fuel overflow in the engine.

/Oivind