glowing downpipe
#5
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Are we talking about a stick DP with the pre-cat? If so the cat may be plugged.
If it is an aftermarket down pipe, do you still have the air pump hooked up? I have read that it is normal for the top portion of the downpipe to glow during start up (when the air pump is injecting air into the exhaust stream). And of course after hard driving. Again this is just what I have read so I am not sure if it is 100% correct.
If it is an aftermarket down pipe, do you still have the air pump hooked up? I have read that it is normal for the top portion of the downpipe to glow during start up (when the air pump is injecting air into the exhaust stream). And of course after hard driving. Again this is just what I have read so I am not sure if it is 100% correct.
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#9
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performance engine mods are aftermarket rx7store.com downpipe with highflow cat and hks exhaust. everything else is rebuild and replacement parts here and there to get the car running straight again. my cat is new so i doubt its plugged. i think NTIMD8 might be correct about the air pump theory. mine has been acting up lately. i know i wont pass emissions but will it mess with the car if i remove the air pump with the stock ecu?
#11
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actually now that i think about it my factory blow off valve has been blowing out a lot of air at idle and start up. iv tried several different bov's and all of them did the same thing. me thinks the air pump scenario might be a winner.
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i was thinking maybe the bov letting off a crap of air at idle and not just a lil might have been caused by a malfunctioning ap. wasnt doing that before. both started acting up almost at the same time. but i think i wanna get rid of the air pump completely i don't need to pass emissions. has anyone done this mode before with a stock ecu???
Last edited by cscsnoise; 09-28-07 at 09:40 PM.
#18
Rotary Freak
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Uhh, running rich actually cools the heat down. It's lean thats causing high temperatuure just like heat creats NOx, and NOx are created under heat/load. The air pump could be the culprit. BUT, you might wanna check the AIR-BYPASS valve, if its always stuck open, constantly throwing air down the exhaust port (downpipe), it will create extreme heat which will cause the downpipe to glow.
#21
Never Ever do that!! hedder wrap does not work on rotarys the headders get so hot that after a couple of days it just burns it up! speaking from personal experience, and it messes up your exaust piping if you got aftermarket because its much thinner it weakens the mettal and leaves the headder vonureable (sp) to crakin....
so in other words not recomended....
so in other words not recomended....
#22
Urban Combat Vet
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Never Ever do that!! hedder wrap does not work on rotarys the headders get so hot that after a couple of days it just burns it up! speaking from personal experience, and it messes up your exaust piping if you got aftermarket because its much thinner it weakens the mettal and leaves the headder vonureable (sp) to crakin....
so in other words not recomended....
so in other words not recomended....
#23
ERTW
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The only time I've seen glowing down pipes or manifolds on rotaries has been when the fuel and timing were out of whack. Rotaries run fine without air pumps and any other emissions related components. Just look at those with simplified setups under the hood.
+1 on header wrap being OK , it keeps the energy where it belongs - inside the exhaust. If parts of the exhaust system are glowing, header wrap shouldn't be used until the root cause is determined
+1 on header wrap being OK , it keeps the energy where it belongs - inside the exhaust. If parts of the exhaust system are glowing, header wrap shouldn't be used until the root cause is determined
#24
~17 MPG
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It's not uncommon for the downpipe to glow a little after a hard run, and I wouldn't be surprised to hear that your downpipe glows after simply idling for extended periods of time.
The stock ECU retards the timing when idling, according to the service manual the leading coils are firing 15 degrees after TDC. This will begin the combustion process late, possibly even allowing some of the air/fuel mixture to continue burning while travelling through the downpipe. This isn't necessarily a bad thing, however: if you ran ignition advance at idle, the parts inside of the motor (rotors, housings, etc...) would heat up more. I wouldn't worry about it too much.
-s-
The stock ECU retards the timing when idling, according to the service manual the leading coils are firing 15 degrees after TDC. This will begin the combustion process late, possibly even allowing some of the air/fuel mixture to continue burning while travelling through the downpipe. This isn't necessarily a bad thing, however: if you ran ignition advance at idle, the parts inside of the motor (rotors, housings, etc...) would heat up more. I wouldn't worry about it too much.
-s-