chim-chim

Hey guys, the other day I started up my 93 r1, and the engine sounded like somebody had ported my engine overnight. Also large amounts of black smoke and backfiring going on. Lots of hesitation untill it's warmed up. After warmup(about 10 min of driving) it all goes away and drives normally. I have a downpipe, intake, cat back, stock ecu. Can't find any vaccume leaks. I am afraid to drive it. Can anyone help. Love my FD.

jspecracer7

Your spark plugs need to be changed....or just cleaned. If you clean them and it doesn't go away, change them.

chim-chim

Would spark plugs cause the engine to run so rich? There is alot of black smoke, and I forgot to metion that flames come out of the exhaust for the first few minutes of warmup. But after warmup exevrthing is fine and the car runs great. The backfires are so loud, and you can really feel them inside the car. I will try your recommendation first. The car sounds like brrp brrp brrp brrp like a lumpy cam sound. Sounds cool, but is this going to hurt the engine any. I am pretty sure the flames probably killed my main cat converter.

jspecracer7

What spark plugs are you using?



It's probably not running rich but because you have no spark (the spark plugs you run may be too high of a heat rating) causing it not to fire and leaving unburnt fuel to come out of the exhaust. Once it gets hot, it sounds like the spark plug gets to it's operating temperature and has no problems firing after that.

FikseRxSeven

most likely what jspec saidif you have cold plugs



the cat is temp sensitive as well. .. .



possiblyrelated to the acclerated warmup system?

chim-chim

I am using the stock plugs, the 7's. I inspected them, yep they look worn. I replaced them about 8k ago, and never cleaned them. Is it normal for them to burn that quick? I was thinking of switching to bur9eq plugs. Any other recommendations. My 7 is a daily driver, and mountain driving on the occasional weekend.