Mr_Wankel

1985 GS, Rebuilt 12a by former owner. Street ported. Manual Transmission.

I recall when I first got the car, I could park it on an angled (decline) roadway by putting it in first gear or reverse, turning off the engine, releasing the clutch and break, and the car was not going to move anywhere. Then I would apply the hand break for added security. Something changed though.

Now, when I do the same on an angled roadway (put in gear; turn off engine, release clutch and break) the car starts inching forward. It feels like small little waves of forward movement, and I can visually see that I am moving forward just by inches at a time. I have to make sure the hand break is fully engaged, keeping it gear alone is not enough

Now, to give you some more info, I think I might have caused this. I was trying to pass someone in a less than ideal situation and I gave it a lot of throttle and didn't release the clutch all the way while keeping the throttle high. I kind of had the clutch released 25% while this was occurring for all of 5 seconds, until I could safely pass. Then I smelled some kind of burnt smell. Perhaps burnt oil or clutch fluid.

Anyway, I am not entirely sure what I may have done, or how things changed from before to now. Can anyone give me some thoughts as to what might be the problem?

grotto107

I had the same issue with my 79 RX7. Gearbox had always held the car in place. Then for about 2 weeks the car would roll while off and in gear. After 2 weeks the engine locked up with a broken apex seal. Do a compression test.

WANKfactor

iTrader: (1)

Its not the clutch. If it slipped in 1st when parked it would be undriveable in the higher gears
the fact its pulsing forward indicates its turning the engine over.
it might not have the compression it once had.

t_g_farrell

iTrader: (1)

Low compression, age.

mazdaverx713b

iTrader: (91)

I agree with the above, a proper compression test with a rotary compression tester is in order. It may run and drive just fine, but test on the lower end of the spectrum.

grotto107

Follow-up
may be a fluke, but mine (above) had less than 20,000 miles when I had these symptoms and my apex seal broke.

peejay

Rotaries have practically zero compression when at near zero speeds, which is why having a battery and starter in good condition is crucial. Also, there is no valvetrain to provide resistance.

You should be able to rotate the engine with moderate thumb pressure on the alternator cooling fins.

peejay

Highly unusual. I wonder if parking in gear may have caused that, engine may have rolled backwards and carbon locked, and then the starter broke it?

Broken apex seals on 12As that were not massively overreved or had heavily worn rotors is practically unheard of.

grotto107

I know. I had driven to the grocery store and it was running finely. When I tried to start it to drive home . Nothing. Starter wouldn't budge it. Thought my battery was dead.
If I remember correctly, Mazda was having problems before 1979 with failing apex seals,and mine came with a 50,000 mile or 5 year warranty (whichever came first).. Mine had about 19000 miles on it , but was about 6 years old at the time. Just my luck.

Mr_Wankel

I didn't add to the original post that my car was in the shop with a seized engine, as I believed (and still believe) the original trouble described in the original post is a separate issue. Earlier I stopped by and was told by the mechanic (rotary specialist) that the oil regulator in the engine failed. He said the rotors didn't get the lubrication they needed and seized. He has the engine pulled apart. He appears to know what to do. Is there anything anyone might advise I make sure is good, whilst the internals of the engine is observable? He says seals and such are as they should be. He says they don't make them anymore and he's getting a used regulator to install. I said, "ok". He is charging me a grand for all this.

Maxwedge

iTrader: (1)

He's right that the OMP (oil metering pump) is no longer available, but it's easily rebuildable. I bought a rebuild kit from Pineapple Racing and it came with a step by step video (CD).

crosen91

I agree with maxwedge I just bought a $20rebuild kit from Atkins rotary. It's pretty much just replacing o-rings. Hey wedge, where was the video at I'd love to have reference before I bust it off and repair it

Maxwedge

iTrader: (1)

The kit from Pineapple has the o-rings, gaskets, stainless screws, an Allen wrench and the DVD all in one kit. I think it does all mechanical pumps. I know it does 12A's and GSL-SE 13's.

crosen91

Damn I was hoping for a link. Guess I'll dig around on there website see if it's on there I have the rings and gaskets. No Allen, no screws, and no video.
Currently it's all 12As for me what with my SA collection. Now to just get room to work

Maxwedge

iTrader: (1)

I couldn't find the rebuild kit when I wrote about it the other night. Just found it.