Firing on one rotor
#1
Full Member
Thread Starter
I was sitting at a stop light and my car just died, fell flat on its face randomly, no engine noise, no popping, just quit. I start it back up and it sounds like a misfire and has terrible acceleration. Checked my coils, plugs, distributor and spark plug wires. They all checked out fine. I'm either getting no fuel or no compression. Or am I missing something. I'm so frustrated with everything going on with my car anymore.
Last edited by Jere Urso; 05-29-15 at 06:08 AM.
#3
84SE-EGI helpy-helperton
Because of the 3 rotor faces on any combustion chamber in a rotary engine - you need a special compression tester to understand what the engine is doing. The standard 'piston' spark-plug compression gauge is good for one reading, usually the highest across the 3 faces, but what you want is the lowest reading.
Zero is pretty low!
In reality, if your compression test came back with zero on the front rotor then you probably lost a seal or two. If you spin the engine over with the starter and listen closely, you should hear several 'whoosh' sounds.
1) If 3 whooshes, this is normal, as all 3 faces are building compression and blowing it out the spark plug hole. Sounds like: "WHooosh, WHooosh, WHooosh, Whoosh, Whoosh, Whoosh, (etc.)" as the engine rotates, and fast.
2) if 2 whooshes, you have 1 rotor face which isn't getting compression - probably due to a side seal going limp. Sounds like: "WHooosh, WHooosh, ... (nothing), Whoosh, Whoosh,... (nothing)" as the engine rotates, and fast.
3) if 1 whoosh, you may have an apex seal gone, as the apex seal covers 2 rotor faces and one apex seal out prevents compression across any 2 adjoining faces. Sounds like: "WHooosh,... (nothing), (nothing), WHooosh,... (nothing), (nothing)... etc." as the engine rotates.
Add some clean engine oil to the front rotor through the spark plug hole to help seal it up and see if you can spin it. Occasionally, seals will stick in place and give the impression that you blew a seal. Avoid doing the 'ATF treatment' until you have nothing left to lose, as the ATF will wash away any 'good carbon' which is helping to seal the oil control rings.
Also, for future reference if you include some details about your car in a signature line, we can help you out better and faster because we know what model car, how many miles are on it, what mods you've done, etc. Good luck, and hoping for the best,
Zero is pretty low!
In reality, if your compression test came back with zero on the front rotor then you probably lost a seal or two. If you spin the engine over with the starter and listen closely, you should hear several 'whoosh' sounds.
1) If 3 whooshes, this is normal, as all 3 faces are building compression and blowing it out the spark plug hole. Sounds like: "WHooosh, WHooosh, WHooosh, Whoosh, Whoosh, Whoosh, (etc.)" as the engine rotates, and fast.
2) if 2 whooshes, you have 1 rotor face which isn't getting compression - probably due to a side seal going limp. Sounds like: "WHooosh, WHooosh, ... (nothing), Whoosh, Whoosh,... (nothing)" as the engine rotates, and fast.
3) if 1 whoosh, you may have an apex seal gone, as the apex seal covers 2 rotor faces and one apex seal out prevents compression across any 2 adjoining faces. Sounds like: "WHooosh,... (nothing), (nothing), WHooosh,... (nothing), (nothing)... etc." as the engine rotates.
Add some clean engine oil to the front rotor through the spark plug hole to help seal it up and see if you can spin it. Occasionally, seals will stick in place and give the impression that you blew a seal. Avoid doing the 'ATF treatment' until you have nothing left to lose, as the ATF will wash away any 'good carbon' which is helping to seal the oil control rings.
Also, for future reference if you include some details about your car in a signature line, we can help you out better and faster because we know what model car, how many miles are on it, what mods you've done, etc. Good luck, and hoping for the best,
Last edited by LongDuck; 05-28-15 at 09:34 PM. Reason: Added what it sounds like, for the hard of reading!
#6
Full Member
Thread Starter
I'll check this before I head to my last day of school tomorrow.
That's always a good way explain how you spent your last days of high school. "Some teenager was distracted while driving and rear ended me at a stoplight going 30 - 40, then the last day of school my front rotor's apex seals exploded at a stop light."
I hope they didn't explode, but I'll have to prepare for the worst.
That's always a good way explain how you spent your last days of high school. "Some teenager was distracted while driving and rear ended me at a stoplight going 30 - 40, then the last day of school my front rotor's apex seals exploded at a stop light."
I hope they didn't explode, but I'll have to prepare for the worst.
#7
Doritos & Dual Sports
iTrader: (8)
I'll check this before I head to my last day of school tomorrow.
That's always a good way explain how you spent your last days of high school. "Some teenager was distracted while driving and rear ended me at a stoplight going 30 - 40, then the last day of school my front rotor's apex seals exploded at a stop light."
I hope they didn't explode, but I'll have to prepare for the worst.
That's always a good way explain how you spent your last days of high school. "Some teenager was distracted while driving and rear ended me at a stoplight going 30 - 40, then the last day of school my front rotor's apex seals exploded at a stop light."
I hope they didn't explode, but I'll have to prepare for the worst.
remove the plugs obviously when listening for the "whooshes", and you can also turn it over from the front crank by hand pretty easily
ATF works wonders, dont leave it in there for more than a few days though as it is corrosive and can do bad things if left in
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#8
Full Member
Thread Starter
I heard that if you have bad apex seals it would burn oil. Mine isn't burning any oil, the exhaust gases are running super clean and there are no catalytic converters. I have a video of turning it by hand I'm about to put it on here. Pretty sure one of them gave out. Checked all the plugs by grounding them, they are all sending tremendous spark.
Last edited by Jere Urso; 05-29-15 at 08:06 AM.
#11
HeyHeyHey..Its the Goose
iTrader: (3)
I heard that if you have bad apex seals it would burn oil. Mine isn't burning any oil, the exhaust gases are running super clean and there are no catalytic converters. I have a video of turning it by hand I'm about to put it on here. Pretty sure one of them gave out. Checked all the plugs by grounding them, they are all sending tremendous spark.
You are thinking oil control rings. Apex seals never touch motor oil (except if you have oil injection).
On a piston job worn oil control rings (similar place as compression rings; which are the piston equivalent to apex seals) will make a piston engine burn oil.
Might be time for a rebuild. I know sounds daunting but after you're done you'll love every minute of the next 50 000 miles.
Last edited by Qingdao; 05-29-15 at 10:10 PM.
#12
Full Member
Thread Starter
You are thinking oil control rings. Apex seals never touch motor oil (except if you have oil injection).
On a piston job worn oil control rings (similar place as compression rings; which are the piston equivalent to apex seals) will make a piston engine burn oil.
Might be time for a rebuild. I know sounds daunting but after you're done you'll love every minute of the next 50 000 miles.
On a piston job worn oil control rings (similar place as compression rings; which are the piston equivalent to apex seals) will make a piston engine burn oil.
Might be time for a rebuild. I know sounds daunting but after you're done you'll love every minute of the next 50 000 miles.
#13
Full Member
iTrader: (1)
Hi Jere, I am real sorry that the motor seemed to let out. I do appreciate your mature and realistic attitude towards it though.
Maybe you have an aunt or uncle that would allow you to store the car until you are in a better place. I am afraid that in a few years these will become difficult to come by. Keep in mind, people my age ( 50) lusted after these cars when new, but the price tag was huge ( in 80s dollars) so now that all the 50 somethings are getting to an age where things are more settled, they want to buy their youth.
I have noticed a run on 7s lately, and I have noticed asking prices that were unheard of just 2 or 3 years ago. I used to see dozens on Craigslist, but now an SA or FB is getting harder to find.
If you can't store it, then don't despair. You will get another if it is a priority. I am not sure an RX7 is the best first car due to the fact that 30 plus year old cars will require work. For me, it is not my daily ride, so I can accept it being down from time to time.
I hope you can work it out as I feel that you added to the 7 community.
I really hope it works out for you.
Rich
Maybe you have an aunt or uncle that would allow you to store the car until you are in a better place. I am afraid that in a few years these will become difficult to come by. Keep in mind, people my age ( 50) lusted after these cars when new, but the price tag was huge ( in 80s dollars) so now that all the 50 somethings are getting to an age where things are more settled, they want to buy their youth.
I have noticed a run on 7s lately, and I have noticed asking prices that were unheard of just 2 or 3 years ago. I used to see dozens on Craigslist, but now an SA or FB is getting harder to find.
If you can't store it, then don't despair. You will get another if it is a priority. I am not sure an RX7 is the best first car due to the fact that 30 plus year old cars will require work. For me, it is not my daily ride, so I can accept it being down from time to time.
I hope you can work it out as I feel that you added to the 7 community.
I really hope it works out for you.
Rich
#14
Always Wanting to Learn
iTrader: (49)
It's just too much, with college coming soon and me needing a daily driver, I just am not in the right head-space to complete a engine swap and restore it. This car was rad, I loved the manual steering, 5 speed, and just how mechanical the car was, it was like a physical connection with the car, its hard to get that in any other car, and I enjoyed every bit of it. It was a great first car and I'm going to have a very hard time adapting to any other car now. But don't worry, I have plans of having another FB in the future.
Another thing, I sold my first 7 as well. Now, I have more rare and amazing parts that I would not have had if I would have kept that car. So I'm very happy and satisfied that I'm where I am now with my projects.
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