still having problems
#1
Full Member
Thread Starter
still having problems
I'm still having intermittent problems w my 79 12a w 25K miles. it ran fine for a month or so but having problems again, just runs bad with backfiring, no power, wont idle. carb is good, the only clue I have is that the tach bounces erratically when it runs bad. I'm thinking ground problems, already replaced battery/starter ground cable, not sure where all the other grounds are.
#2
Uncle Rico
iTrader: (5)
I'm still having intermittent problems w my 79 12a w 25K miles. it ran fine for a month or so but having problems again, just runs bad with backfiring, no power, wont idle. carb is good, the only clue I have is that the tach bounces erratically when it runs bad. I'm thinking ground problems, already replaced battery/starter ground cable, not sure where all the other grounds are.
#4
Full Member
Thread Starter
all that stuff has been done w less than 4k on it. tank cleaned and coated, new pump, filter, hoses, points, plugs, cap, wires, battery, condensers, etc. all new, rebuilt carb. the tach bouncing whenever it acts up makes me think it's an electrical problem. and because it's intermittent and will go away for awhile, run great and then the problem comes back. I also swapped out the trailing coil, and that made no difference.
Last edited by Steve Adleman; 09-03-23 at 06:31 PM. Reason: more info
#5
Senior Newbie Member
all that stuff has been done w less than 4k on it. tank cleaned and coated, new pump, filter, hoses, points, plugs, cap, wires, battery, condensers, etc. all new, rebuilt carb. the tach bouncing whenever it acts up makes me think it's an electrical problem. and because it's intermittent and will go away for awhile, run great and then the problem comes back. I also swapped out the trailing coil, and that made no difference.
The following users liked this post:
Frogman (09-04-23)
#7
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,829
Received 2,597 Likes
on
1,845 Posts
tach bouncing = ignition not being right, which is probably the points
Trending Topics
#9
Senior Newbie Member
My gas cap was bad and I had my tach bouncing and engine fumbling every time I let the car sit for a few days . I suspect air or moisture would get into the system and after driving it tor a bit it would purge itself. Worth a try since you say you have changed everything else as I did .
#10
Full Member
Thread Starter
#12
Rotary Enthusiast
iTrader: (2)
This is probably really a stretch, but maybe one of the ignitors is going bad. I lost an ignitor years ago, which resulted in loss of the tach signal and the fuel pump operation. It stopped the car on me a couple of times, but then would restart again after some cooling down and would then seem fine for a period of time. Maybe your signal is more erratic, causing an on again off again situation. The '83 wiring diagram shows a wiring coming off the trailing ignitor. Not sure if that is the same for the SA. I don't know how the ignitor affects the fuel pump, since I can't see a direct connection in the wiring diagram, but it definitely caused my fuel pump not to work when the ignitor was on the fritz. Maybe it is through the ECU?
Good Luck
Carl
Good Luck
Carl
The following users liked this post:
Frogman (09-04-23)
The following users liked this post:
Carl (09-04-23)
The following 2 users liked this post by Carl:
diabolical1 (09-04-23),
KansasCityREPU (09-04-23)
#16
Full Member
Thread Starter
going to check points/dist, vacuum, going to clean every connector and connection I can find and maybe change the gas cap
#18
Full Member
Thread Starter
no. but when it does I know I'm in for a rough ride
#21
Out In the Barn
iTrader: (9)
The motor can rev but not respond to speed/RPM increases. The tach however would appear to work properly. I'm just trying to think of other things since the OP seems to have covered all the other possibilities and says those things are fine. My bet is still the dizzy though.
#22
Senior Newbie Member
The motor can rev but not respond to speed/RPM increases. The tach however would appear to work properly. I'm just trying to think of other things since the OP seems to have covered all the other possibilities and says those things are fine. My bet is still the dizzy though.
In other news , My gas cap fix didn't entirely clean the issue up. RIp engine .
#23
Full Member
Thread Starter
after thoroughly checking ignition system points, coils, battery, etc good spark at plugs, 13v at pos coil terminals, swapped coils, fusible links good, it was running ok for a while, then yesterday started acting up again, checked everything again, no change, I suspected the ignition switch might be a problem after seeing posts about how they are known for deteriorating, so I worked the switch a bunch with the battery disconnected, and the problem seemed to get worse, now the tach barely works at all, still bounces some but mostly doesn't work, car still runs but doesn't like to rev much still. question is does the tach signal go through the ignition switch? if so that could be the problem maybe? reluctant to pull the switch and take it apart if I don't need to, but maybe I should?
#25
Full Member
Thread Starter
disassembled, cleaned and reassembled ignition switch, lubed w electrical grease, no difference, if anything ran worse. dropped it off at a shop because it wouldn't make it home, hopefully this guy can find something, apparently he's doing a 2nd gen of his own so isn't a stranger to rotaries. mechanics are retiring in my town so there aren't many options to have auto work done here, but I'm hoping for the best.