1985 gs...stock (12a)

new coils, plugs, relatively new wires, cap, rotor, battery, starter wire (red lead) and ground wire to battery

strut tower ground checked, sanded down, and reattached.

new starter and alternator


The problem is that the car would lose power....intermittently. Not total power, just some (power as in hp, or whatnot). It would max out around 45 mph or so, then all of a sudden regain the power as if all plugs were not firing.

Not only this, but the rpms dropped significantly to about 500, and now it will stall out. I ended up raising the idle to counter this to run the car and test things.

Now it's where it doesn't have the power ever, always seems like its running on one rotor or something of the sort. It's getting fuel, but doesnt seem to be burning it all. Plugs were relatively dark but not fouled (all 4 seem to be firing). Coils are perfect, and I am in the process of checking the igniters.


Could this be an electrical ground problem? Or something in the distributor like the rotor? If I do take the cap off of the distributor, what are the tell tale signs of a problem in the dizzy? Wear on the edges of the rotor?.

Any help is great, thanks guys

 

I don't want to send you off on a wild goose chase, but have you checked you're fuel filter? Sounds to me like you're starving for fuel....

 

Good call...but i just changed it....forgot to mention that. Maybe something got into the system...i dont know. I added a second filter...but if i remember correctly i had this problem first, cant guarantee it

 

Sounds like leading plugs are not firing. This based on the description mostly.

How do you know the plugs are all firing? Did you try pulling one plug wire at a
time to see if it affects the running engine. Thats the easiest way I know to find
a dead plug if it at least runs. Have someone keep it running by giving it gas and
try removing each leading plug one at a time. If neither affects the way it runs then
one or both are not firing.

 

Sticking apex seal? I had a similar problem and one of the seals was sticking down temporarily losing compression.

 

we had one come into the dealership in 2007, that intermittently did what you describe. it took a while to figure out WTF it was doing but it turned out that the TPS was bad, and would close the shutter valve, thus running on 1 rotor.

new TPS, and viola, like new.

fuel pump might be worth a test too.

 

Tps?

 

i assumed they are all firing because they all look the same and the engine runs. Whats the safest way to remove the plug wires while running the car? Rubber gloves?

 

Yeah I wouldn't do that if I were you. I've seen someone take the exact same advice and get the **** shocked out of him. You could get one of those see through testers that go between the plug and the plug wire to check for power.

 

I think black dragon sells them...definitely the route im going haha

 

black dragon def sells them!

 

checking spark i take out each spark plug and wire, and then while someone is turning the key i ground it on one of the bolts of the strut mount. check for arcing

check fuses for electrical issue first though

 

You reach down and pull the boot. If you get shocked that means you have crap
for wires. Its not that bad if you get shocked anyway. Man up!

BTW, theres no TPS on our cars except maybe for the GSL-SE which you don't
have.

 

yes there is! the 79-80's have an idle switch, but the 81-85's have a Throttle Position Sensor. its used to run the emissions system.

http://mazdatrix.com/c-6.htm

 

+1 to j9fd3s

 

Emissions! Who needs that?

Ok, you got me but its not a TPS in traditional sense when used with EFI.

Still think its leading spark issue.

 

It monitors Throttle Position, and an ECM makes things happen based on that. Just like EFI.

:OP

 

i love the enthusiasm...but ive done the grounding/arc test and got spark....along with a nice shock up the arm haha. I guess my wires are crap?

 

What makes you think its a leading ignition issue? And also, could the tps just go like that?

 

Because of the description of the failure in the first post.

Have you been able to check the spark when it actually is acting like this?

Cause it sounds like when it loses power and won't go over 45 that its just
running on the trailing or one rotor.

So heres the things it could be from minor to major:

1. Just flooding out for some reason. Do the de-flood procedure to make sure thats not the issue.

2. Rats nest issue of some sort. If you still have all the emissions crap on there it could be messing with you.

3. A stuck seal. Letting it warm up and revving to 4 or 5 k should fix it. Seafoam can't hurt either.

4. Spark issues. Check cap rotor and wires. Sounds like wires are crap already.

5. Failing ignitor(s). They usually start failing once the car gets hot and work fine when cold. FSM has procedure for checking.

6. Lost compression on one or both rotors in some fashion. Do the ghetto compression check and see if all faces bounce to the same values on both rotors.

 

Enlighten me about this compression test...i may try it. And as of the last couple weeks....its always acting like this...so i just have to check the spark when i can.

 

https://www.rx7club.com/showthread.p...mpression+test

 

i like #5, leading ignitor.

 

I've swapped igniters, unfortunately to no avail. I will check them this weekend. Unfortunately, the issue I'm having is and has been 100% of the time (last few weeks) so unfortunately revving the motor or letting it get warm doesn't help

 

Pull you exhaust manifold and check to see that all the apex seals move (hand turn the motor)- just push them with a finger, etc. Any rough feeling and you might have a sticking seal.