Blown 12A? What to look for before test
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Blown 12A? What to look for before test
Hey guys, I did a search on blown apex seals and found quite a bit of information. I am going to take a regular compression tester and take the schrader valve out of it and check the compression. However, I am unsure that the apex seal is blown due to the following symptoms:
The car will only do 40 MPH, floored, and a rough idle, both symptoms. However, the car starts very easily, like one spin of the starter. It will not stay running without the choke (idling). When revved up it vibrates less but is still not smooth. It takes a long time to rev it up if you floor the accelerator.
I am going to go ahead and check compression but is there anything else I should look for? Car is a well maintaned 84 from California, 148k miles. Thanks all
EDIT: I forgot to add, that if I do conclude that it is an apex seal, can I pull the engine apart and just replace the apex seals and other misc seals? I am not so concerned about having a long lasting new/rebuilt motor because I have a good 13B to put in later.. Thanks
Brian
The car will only do 40 MPH, floored, and a rough idle, both symptoms. However, the car starts very easily, like one spin of the starter. It will not stay running without the choke (idling). When revved up it vibrates less but is still not smooth. It takes a long time to rev it up if you floor the accelerator.
I am going to go ahead and check compression but is there anything else I should look for? Car is a well maintaned 84 from California, 148k miles. Thanks all
EDIT: I forgot to add, that if I do conclude that it is an apex seal, can I pull the engine apart and just replace the apex seals and other misc seals? I am not so concerned about having a long lasting new/rebuilt motor because I have a good 13B to put in later.. Thanks
Brian
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I had engine probs once. I was about to order a new engine from Mazda when I located a rotary specialist. I took it to him and he fixed it. Underneath the carb is another "butterfly" valve. The pin had broken and the valve closed off the hole. Just a suggestion but my car had the same symptoms and I'm still driving it after getting it fixed 30,000kms later and it runs as well as it did before.
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Originally posted by KritterMac
I had engine probs once. I was about to order a new engine from Mazda when I located a rotary specialist. I took it to him and he fixed it. Underneath the carb is another "butterfly" valve. The pin had broken and the valve closed off the hole. Just a suggestion but my car had the same symptoms and I'm still driving it after getting it fixed 30,000kms later and it runs as well as it did before.
I had engine probs once. I was about to order a new engine from Mazda when I located a rotary specialist. I took it to him and he fixed it. Underneath the carb is another "butterfly" valve. The pin had broken and the valve closed off the hole. Just a suggestion but my car had the same symptoms and I'm still driving it after getting it fixed 30,000kms later and it runs as well as it did before.
Thanks a ton. I'll check it out tonight.
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that "other" butterfly valve is the infamous "Shutter Valve" if it closes, the car won't idle right, and there will be a lack in power.... but I dunno if it would cause the car to only go 40mph floored.... I suppose if it was closed right off, the car would only be running on one rotor...
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Originally posted by Keaponlaffen
that "other" butterfly valve is the infamous "Shutter Valve" if it closes, the car won't idle right, and there will be a lack in power.... but I dunno if it would cause the car to only go 40mph floored.... I suppose if it was closed right off, the car would only be running on one rotor...
that "other" butterfly valve is the infamous "Shutter Valve" if it closes, the car won't idle right, and there will be a lack in power.... but I dunno if it would cause the car to only go 40mph floored.... I suppose if it was closed right off, the car would only be running on one rotor...
I guess I should ask, do I take the carb off to take a look at it? I am not very familiar with these even though this is my third 7.
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#8
What about a clogged cat? Mine did most of what you discribed when my cat disintegrated. I could floor it and only go about 35. But it was hard to start, not one of your symptoms.
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ok now im replying to something that im just guessing at here....
but if you remove the air filter, you can feel suction from the air pump hole if its functioning properly. i THINK one of the smaller holes further back goes to the shutter valve, right?. if so, is there a way to check to see if its operating by that hole?
but if you remove the air filter, you can feel suction from the air pump hole if its functioning properly. i THINK one of the smaller holes further back goes to the shutter valve, right?. if so, is there a way to check to see if its operating by that hole?
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I'd definitely say the shutter valve is the culprit, but there' could be a vacuum leak somewhere too. and the Cat is a possiblilty, so check all of these, and replace your fuel filter too, while you're at it.
#15
Originally posted by wagondriver69
So whats goin on, if one of your seals is bad, is it really simpler to replace the whole motor than take it apart and fix it?
So whats goin on, if one of your seals is bad, is it really simpler to replace the whole motor than take it apart and fix it?
Forcus: Does your engine sound the same as it did before these symptoms occured (assuming you know)? Mine sounded much different and worse after I blew a seal. Go figure, right? I still had a good bit of power after it went, but most of my seal stayed in the rotor.
Conway
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I bought it this way. I figured since I have a very rusty 85 GSL-SE with a supposedly good engine, and a very nice 83 with a bad engine.. well you can do the math
Probably what I will do though is confirm that the GSL-SE motor is good, then take the 12A out and tear it down to see if the housing is chewed up. If so, and a replacement is not resonably priced, I'll convert the works over to a fuel injected 13B
Probably what I will do though is confirm that the GSL-SE motor is good, then take the 12A out and tear it down to see if the housing is chewed up. If so, and a replacement is not resonably priced, I'll convert the works over to a fuel injected 13B
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I would believe that but a tuneup wouldn't fix the zero compression showing on each face of the rotor
I'm physically checking out the apex seals through the exhaust ports today. I'll let every one know what I find.
I'm physically checking out the apex seals through the exhaust ports today. I'll let every one know what I find.
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yeah, check the compression first, that way you know wheather to keep looking, or not.
mike
mike
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Well I took the exhaust manifold off today and looked at a couple of the apex seals on the forward rotor. I found a tiny notch in one of them. It was about 1/3 inch long and maybe 1/16 or 1/32 deep. I would guess that would be enough to affect compression.
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