Ironman

The stuck seals possibility is intriguing. I've searched around this board some more and found some suggestions such as:

Pour a few capfulls of motor oil down the carb to free up the seals.

or

Mix a can of Seafoam with 1/8 tank of gas and then flog it for a while.

Are either of these good things to try?

Jeezus

iTrader: (4)

I take it that you have already checked the compression through the spark plug holes?

Stuck apex seal can possibly be cured by the oil. Marvel Mystery Oil and Automatic Transmission fluid are popular choices around here, but I think anything oil is good. Make sure you pour a capful on each face of the rotor, front and rear rotor. I let it sit for a day and really get in there. Make sure you turn the rotor by hand some as well. Start 'er up and hope for the best. Seafoam would be the next thing if you like. Preferred, yes. Necessary, no.

Good luck

Ironman

I took the leading plugs out and did the "whoosh" test. Bear in mind I don't know exactly what I'm listening for....

The rear rotor has 3 whooshes of about equal strength. The front rotor has one of this strength, one of slightly lesser strength, and one I can barely hear. But it is still audible.

I put the plugs back in and poured 4 capfulls of ATF down the primary venturi of the carb, turning the motor over one revolution between each. Then I turned it by hand another ten times or so. I'll let it sit overnight and see how it runs tomorrow. Hope for the best.

boyee

iTrader: (3)

i am also in a similar situation with you and i dont mean to lecture but i would like to share something that a good honest rotary mechanic who has been around rotaries for a long time told me:
as these cars are getting older, fewer and fewer will be getting off the street due to people junking them because they dont want to fix their car, rust, etc. but maybe one day our cars will become something of value like the older rotaries are getting such as a rx2 or repu, etc. the beauty of owning a classic car is that you will have to keep putting more and more money into your car to fix it up. it takes a lot of love and passion for your car to keep it and keep putting money into it. if you dont have those or do not want to spend that much money on it right now but still want to drive an rx-7, you can probably find a nice rx-7 that has its engine already rebuilt and is reliable to drive on the road with a clean body and interior for about half the price its gonna cost to rebuild your engine alone and you dont have to do any work on the car but drive it. again this is the beauty of owning a classic car and you need to have a lotta love to keep it and work on them to have it in good condition all around. its your choice on what you want to do with your car.

i hope that helped you out and gave you something to think about towards fixing your engine and have your car drivable again. good luck

Ironman

OK, status report:

After pouring some ATF down the carb, turning over by hand, and letting it sit for a night, I started it up, let the smoke clear, and poured a pint of Seafoam in about 1/5 tank of gas. Then I took it out and drove it like I stole it.

Power is noticeably increased: I can break the tires loose on a launch relatively easily now and they will chirp on a hard 1-2 shift. I timed 0-60 just counting off seconds to myself and got 12-13 or so. Who knows how accurate my mental stopwatch is, but isn't the factory time around ten seconds?

Also, it will now IDLE WITHOUT THE CHOKE. It still dies sometimes, but I can prevent this by just touching the accelerator for a split second. Then it will just idle (albeit somewhat lumpily) at 750 RPM.

This is definitely better. The thing to do now, I think, would be to go get the compression checked again. Can just any shop do this, or is a rotary specific tester really needed? I ask because the nearest Mazda dealer is about 50 minutes away.

Rx-7Doctor

iTrader: (13)

Spend the $30.00 or so on a regular compression tester and do it yourself. The procedure is listed in the Archives.

Jeezus

iTrader: (4)

Glad to hear it is back up and running!

blwfly

iTrader: (4)

sounds like the carb needs a rebuild to..
usally the idel circuit in the carb gets clogged up with varnish etc..
as well as other posibilitys dose the car still have all the emmisions.

Ironman

Yes, all of the emissions systems are stock.



I'll go buy a compression tester tomorrow and test it myself.
Thanks for the help, guys. Things are beginning to look up.

meangreenrotarymachine

First of all, that 13b motor is 900$ INCLUDING ECU, am i right?
Personally, i think it's an awesome idea. Mind you that shipping is an additional
cost plus custom installation. Not taht much though.

Second of all it's such a good idea that i will be doing that same for my 85 gsl-se
rx-7. But i will be looking for a turbo 2nd gen motor. The rx-7 is so worth it bro!

meangreenrotarymachine

WOW there!!!! No regular compression testers allowed!!!
I can guarantee you that a regular tester is useless.
I even checked it in a service manual for 79-85 rotaries - some sort of tester that
can read each three rotor sides independently. TRUST me man.

meangreenrotarymachine

Getting the test at mazda with a data result sheet is just a better choice.
I think.

Rx-7Doctor

iTrader: (13)

Trust you? LOL.

For our purposes the standard compression tester is sufficent. That's why we have a thread archived that explains how to use a standard tested on a Rotary. You might want to view the thread.

If you read the whole thread(responding to your next post) you would of seen that he already got a compression test at the Mazda Dealership. Which they did not supply him with results and when he called back no one there could read the print out. He also stated that it is 50 minutes away.

I have been using a standard compression tester on rotaries for 20 years to help to determine the condition of the engine.

meangreenrotarymachine

can you direct me to that thread then?
I'm interested to learn how it's done. But you have to agree that there is
a compression tester designed for the rotary. Probably it can be bought at mazda
dealerships etc.

Rx-7Doctor

iTrader: (13)

Yes, and yes. At a cost of around $900-$1000 for the tester. Care to buy one?

link is https://www.rx7club.com/1st-gen-archive-71/engine-compression-test-using-piston-engine-tester-597883/

Rx7carl

Good deal Ironman. I would suggest repeating the treatment till no improvement is noticed. You may still have carbon buildup. Then check the compression. Also a full tune up if you havent already should be done. Cap, rotor, wires, plugs, fuel filter, air filter, oil and filter change, ign timing check and check that all plugs are firing. And keep running some fuel system cleaner for a while. Carbs tend to get gummed up from sitting and short of rebuilding it, the cleaner can sometimes take care of that.

And my other suggestion is to post in your regional area to see if you can get some assistance from a fellow member.

Ironman

Well, I did the compression test today, and the results aren't good. I used this procedure:

http://www.rotaryresurrection.com/1s...ion_check.html

With the gauge's release valve held open, the front rotor reads 60, 60, 60. (All this is in PSI) With the valve closed, it reads 90. This is relatively healthy, right?

The back rotor, however, is a different story. It reads 60, 30, 15 with the valve open and 85 with it closed. This means I've got blowby on one of the apex seals, yes?

The funny thing is, when I did the ghetto (gaugeless) test two days ago, the front rotor sounded worse. I'm pretty sure I didn't mix them up, so perhaps the carbon treatment unstuck the front rotor seals but not the back? I think next I'll try some of the more radical suggestions for decarbonization found in this thread:

https://www.rx7club.com/showthread.p...hreadid=281207

JCurry

iTrader: (6)

ya dump some mmo in the spark plug holes making sure to get it on all faces then let it sit for 24 hours and see how that goes.... hope u get it up and goin...

Latin270

Better yet, go w/ a 13b.