Not starting issue, also interior lights for radio, door handle, horn, have stopped working?

Tiny
REX787
  • MEMBER
  • 1987 MAZDA RX7
  • 3 CYL
  • 2WD
  • MANUAL
  • 98,000 MILES
Like many others, my car listed above turbo has trouble starting and a mechanic put in the switch that I can turn off gas supply when cranking, and then back on when it started over 10 years ago. This problem is worse in hot summer weather. Have replaced battery, spark plugs, starter, etc. I’ve stopped driving it for the past 3 years and just run motor at home 1-2 times a month. Now I have a problem with the other electrical parts, interior lights for radio, door handle, horn, have stopped working. Car is kept in garage and no rodents to bother with the wiring. I love my car but have given up on finding a mechanic who knows about rotary engines to do repairs. I have the original manual and my husband can do some repairs but has given up on finding a solution. Hope you can give clues!
Saturday, October 21st, 2023 AT 4:15 AM

1 Reply

Tiny
STEVE W.
  • MECHANIC
  • 14,155 POSTS
Most times the hard starting is due to the rotor tip seals letting oil in while the engine sets, then you try to start it and it fouls the plugs. By turning off the fuel it can help some because you can somewhat clear the buildup out by cranking it and distributing the oil as well.
Electrical wise, I hate to say it but even in a garage you could have critters, but the more common thing is simply time and corrosion in the old-style connectors. About the only solution that works on classics is to start at one end, go to a connector, open it up, inspect it and spray in some DeOxit. It removes the thin layers of oxides and when you reconnect it stays in place to help prevent further corrosion. When it comes to switches and such it also works in those. It's a lot of work but I have seen some amazing results doing it on my vintage cars. The only good thing is that being an 87 it isn't as bad of a harness as a modern car.
The reason it is worse in the heat is simple. In the colder/damper weather the conductors will shrink in a miniscule amount and improve the connection just enough that it works.
I would start there. Also, clean and redo all the grounds where they bolt to the chassis. It's a shock sometimes just how poor the connections get over time.
Was this
answer
helpful?
Yes
No
Wednesday, October 25th, 2023 AT 3:03 AM

Please login or register to post a reply.