Is my 12a dead?
05-05-08, 04:05 PM
#1
Is my 12a dead?
I've searched around and no one has quite these set of circumstances...
Heres the story
Few days ago I was driving around enjoying my 1st gen like any respectable owner would be.. Few 7.5k shifts here and there to keep the ports clean and whatnot.. all is fine.. but then coming up to the red light the RPMs fall quickly and the car almost dies, i kept it alive with the gas pedal.. immediately turned down my music in concern and listened closely, it felt short of power and sounded a bit different as I drove.. this happened close to home and I managed to make it there and garage it.
There was no noise, no pop, or bang, i didnt feel anything at all.. just suddenly happened.
So at the garage I started testing a few things.. I read on here someone had lost their leading ignition.. I switched out to my spare coil and my spare set of plugs and same result. I tested the spark on the leading and sure enough.. its there.. I cannot think of what could be wrong other than the worst.. rotor seals..?
I've attached a few videos of it running, and attempting to idle.. the engine shakes violently when I try... it no longer idles on its own. Now the car sounds like its ported or something, when in fact its not.. my rx7 is sick
First video is warming up with the choke pulled.. not idling
Heres the story
Few days ago I was driving around enjoying my 1st gen like any respectable owner would be.. Few 7.5k shifts here and there to keep the ports clean and whatnot.. all is fine.. but then coming up to the red light the RPMs fall quickly and the car almost dies, i kept it alive with the gas pedal.. immediately turned down my music in concern and listened closely, it felt short of power and sounded a bit different as I drove.. this happened close to home and I managed to make it there and garage it.
There was no noise, no pop, or bang, i didnt feel anything at all.. just suddenly happened.
So at the garage I started testing a few things.. I read on here someone had lost their leading ignition.. I switched out to my spare coil and my spare set of plugs and same result. I tested the spark on the leading and sure enough.. its there.. I cannot think of what could be wrong other than the worst.. rotor seals..?
I've attached a few videos of it running, and attempting to idle.. the engine shakes violently when I try... it no longer idles on its own. Now the car sounds like its ported or something, when in fact its not.. my rx7 is sick
First video is warming up with the choke pulled.. not idling
05-05-08, 05:02 PM
#3
I dont have a working piston compression tester.. but I did take out one spark plug at a time on each rotor, took out eng. fuse, cranked the engine and listened for the poofs..
Front rotor sounds like POOF POOF POOF.. Rear rotor seems like its going POOF POOF POof.. its not that much less.. but it is
would that cause this much trouble with the idle and such?
Front rotor sounds like POOF POOF POOF.. Rear rotor seems like its going POOF POOF POof.. its not that much less.. but it is
would that cause this much trouble with the idle and such?
05-05-08, 09:20 PM
#5
***UPDATE***
I jacked up the carb idle screw and managed to get it running at about 800 rpm.
It revs up and idles well enough so I decided to take er for a test drive around the block.
Basically the car feels like a cammed V8 at idle, even low rumbling and shaking.. in the low RPMs it sounds like a small block v8 accelerating.. and at high RPM it sounds like it should, a rotary..
Very odd I must say.. I still have no idea what is wrong.. but I did notice when revving by hand in the engine bay.. the carb occasionally spits up a little bit of fuel.. makes me wonder if one of the chambers on one of the rotors is not igniting.. either a spark issue or compression.. more likely compression.. and most likely need rebuild..
I hope this helps.. I would like not to rebuild at this time.. but I will if i have to
I jacked up the carb idle screw and managed to get it running at about 800 rpm.
It revs up and idles well enough so I decided to take er for a test drive around the block.
Basically the car feels like a cammed V8 at idle, even low rumbling and shaking.. in the low RPMs it sounds like a small block v8 accelerating.. and at high RPM it sounds like it should, a rotary..
Very odd I must say.. I still have no idea what is wrong.. but I did notice when revving by hand in the engine bay.. the carb occasionally spits up a little bit of fuel.. makes me wonder if one of the chambers on one of the rotors is not igniting.. either a spark issue or compression.. more likely compression.. and most likely need rebuild..
I hope this helps.. I would like not to rebuild at this time.. but I will if i have to
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05-05-08, 09:46 PM
#9
djessence
***UPDATE***
I jacked up the carb idle screw and managed to get it running at about 800 rpm.
It revs up and idles well enough so I decided to take er for a test drive around the block.
Basically the car feels like a cammed V8 at idle, even low rumbling and shaking.. in the low RPMs it sounds like a small block v8 accelerating.. and at high RPM it sounds like it should, a rotary..
Very odd I must say.. I still have no idea what is wrong.. but I did notice when revving by hand in the engine bay.. the carb occasionally spits up a little bit of fuel.. makes me wonder if one of the chambers on one of the rotors is not igniting.. either a spark issue or compression.. more likely compression.. and most likely need rebuild..
I hope this helps.. I would like not to rebuild at this time.. but I will if i have to
I jacked up the carb idle screw and managed to get it running at about 800 rpm.
It revs up and idles well enough so I decided to take er for a test drive around the block.
Basically the car feels like a cammed V8 at idle, even low rumbling and shaking.. in the low RPMs it sounds like a small block v8 accelerating.. and at high RPM it sounds like it should, a rotary..
Very odd I must say.. I still have no idea what is wrong.. but I did notice when revving by hand in the engine bay.. the carb occasionally spits up a little bit of fuel.. makes me wonder if one of the chambers on one of the rotors is not igniting.. either a spark issue or compression.. more likely compression.. and most likely need rebuild..
I hope this helps.. I would like not to rebuild at this time.. but I will if i have to
Did you check ignition. I mean its dead simple to check and is the solution to a TON of problems with these cars.......
05-05-08, 09:58 PM
#12
djessence
05-05-08, 10:42 PM
#15
OH! sorry doc, didn't see your first post
I have the stock carb with the RB air cleaner.. and full RB exhaust
Dj: I tested leading spark.. so the ignitor must be fine.. but I did not test each spark plug individually..
And actually.. during the drive.. it did not feel too much less of power than normal.. it is noticeably less.. but not drastically.. I still am quicker to speed than most of the traffic not even trying
I'm using a second gen coil.. the 2GDFLIS system as stated in the archives
I have the stock carb with the RB air cleaner.. and full RB exhaust
Dj: I tested leading spark.. so the ignitor must be fine.. but I did not test each spark plug individually..
And actually.. during the drive.. it did not feel too much less of power than normal.. it is noticeably less.. but not drastically.. I still am quicker to speed than most of the traffic not even trying
I'm using a second gen coil.. the 2GDFLIS system as stated in the archives
05-05-08, 11:27 PM
#17
Thats possible.. I figure I'll change my fuel filter just to rule that out.. but I've never taken apart the nikki before.. how simple is it? can I leave it on the car to check for clogs?
Just before this happened this 12a idled happily at about 600 RPM without a hiccup..
Just before this happened this 12a idled happily at about 600 RPM without a hiccup..
05-05-08, 11:57 PM
#19
Rats nest removed, PCV installed.. I checked all my vacuum hoses for leaks with carb cleaner
Shutter valve removed and sealed with JB weld long ago
Air pump and ACV removed and appropriate blockoff plates with gaskets installed..
I wish it was something as simple as that
Shutter valve removed and sealed with JB weld long ago
Air pump and ACV removed and appropriate blockoff plates with gaskets installed..
I wish it was something as simple as that
05-06-08, 10:13 AM
#20
4x110 SUCKS!
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Didn't see alot of smoke associated with blown seals, check trailing ignition as-well, alot of people think it's not needed, but If it wasn't I think mazda wouldn't have it on the cars.
05-06-08, 11:46 AM
#24
My trailing must be strong, because just yesterday when I was messing around with the leading, I went to start it, and it took lots of cranking and it ran like ****.. and I
thought oh **** I broke something, but I realized I had not hooked up the leading coil hahaha
It was actually running on only the trailing though.. hooked up the leading and i'm back to where I was
thought oh **** I broke something, but I realized I had not hooked up the leading coil hahaha
It was actually running on only the trailing though.. hooked up the leading and i'm back to where I was
05-06-08, 03:27 PM
#25
Usually if your engine will fire with just the trailing then the compression as a rule of thumb is pretty good.
I would still invest in a compression tester (everyone that owns one of our cars should have one,lol.) and perform the test.
Also would use a timing light and test each plug wire as the engine is running to verify they are all firing.
I would still invest in a compression tester (everyone that owns one of our cars should have one,lol.) and perform the test.
Also would use a timing light and test each plug wire as the engine is running to verify they are all firing.