quick 7

hey, I think my car is runing only one one rotor.
When I start it barly idles and when it does it its very rough. It can be driven, but it has very little power and stalls if im not careful, it also backfires alot. Any Ideas what the problem is? I've tried the ATF trick and nothing changed. Im guessing it needs a rebuild

Thanks

vhold

Well I'm no expert, but that's almost exactly what my car was like when I blew my apex seal

FPrep2ndGenRX7

I would check the compression first. The problem you described was one I've had also. The flap in my AFM(air flow meter) had sticky tar stuff on it from somewhere and that keep it from moving freely. My car would barely start and not hardly idle either. I cleaned it up and no problem, but still check the compression if AFM isin't the problem. After that verify its not a clogged filter or simply replace it if its been 30,000 miles or so. Even if the fuel filter isin't the problem its good to replace them regularly. Might also want to check the catalytic convertors(if you still have them) and make sure they are not clogged up.

13BAce

Did anything happen before this started?

tesla042

Here's a quick way to see what may be wrong..

Pull the EGI fuse. Pull the plug wires off all plugs. Now ,remove one of the FRONT ROTOR's plugs.. just one...so you have 3 left in. Get your buddy to crank the engine.. Have him floor it while he cranks it to allow more air in. you should hear (real fast), "psst psst psst psst psst psst" over and over.. if you hear this, the apex seals are likely still intact.

What you do NOT want to hear is "psst pfff pfff pssst pff pffff".. Note the difference. The "psst" is a sharper sound, and the "pfff" will sound weaker. That likely means that an apex seal is gone.. If you hear "psst psst pfff psst psst pfff", it could be a side seal, but that's unlikely.

Now that you know your front rotor is good (it will be.. it's almost ALWAYS the rears that go), put the plug back in and do the same thing for the rear rotor..

Hope it's just the AFM like someone above said!

-Tesla

quick 7

before this the car was running great, the only thing that might have hinted at a blown seal was a very little bit of white/blue smoke, This would only happen when going really slow and wouldn't happen very often.
Thanks for the help

13BAce

It could be a problem with your air flow meter.

Wargasm

I agree with the other poster above...

My car did this once and I thought I blew the engine. I checked the compression and it came back perfect. Turns out that my airflow meter had gotten stuck most of the way open! A simple tap on it and all was well.

Check the compression; if that is good, check the AFM and intake tubing.

Brian

87 TII
93 R1

quick 7

I checked the AFM and it seems fine, I opened and closed and it moved freely. I phoned the local mazda dealer and im gonna borrow their compression
tester next week. any other ideas?
Thanks for the help

13BAce

Have you checked it according to the factory service manual?

13BAce

Air flow meters suck. That's what's great about the standalone ECU's: No air flow meter.

quick 7

Do mean the Haynes service manual or the Mazda factory manual?
thanks

13BAce

You may be able to use the Haynes manual if it has the information on how to test it. The Mazda manual tells you how to test the AFM.

baix2

my car does that on start up also...running only one rotor...
but then after a while, it will be fine...
about 10 secs...

i think it's my injectors...need to be cleaned...
and normally the car idles perfect

13BAce

It could be a problem with the TB. My car ran that way when I put the new motor in 2 years ago, but adjusting the TB fixed it.

Suparslinc

Use a small mirror and flashlight to peer inside the plug journals.
turn the engine by hand with a belt until you see 3 shiny apex seals in each housing. If not, then thats bad news.