Running Rich ??

wantan17

Registered User
my '89 sc seems to blow black smoke at wot (or near it) this happens mostly when it starts up but also when it has been running for more than 30 minutes. heres the catch i haven't check my 02 sensors yet and a few months ago i had my cats gutted and resonator deleted. so the question is what are the characteristics of running rich and could the problem be solved with buying a new set of 02s and should i move the passenger side 02 to the same position that the 02 is on the driver side to counter the problem without having catalytic backpressure heat to give the sensors a good reading. thanks....please reply.
 
Normal for a stock SC

EEC-IV does this at WOT to prevent the headgaskets from parting ways. You can change some of those things out, but you'll still have it to one degree or another.
 
BTW, smoke at startup (blue) is valve stem seals. Are you getting black at startup? Or blue?

If you're getting black smoke at initial startup, then yes, somethings amiss. But at WOT it's expected.
 
Well, hard to say. Most SC's I've known (including mine) don't do this at start up, BUT...It's also normal for many cars as the computer richens the fuel mix on cold start . This is perfectly normal...to a point.
I guess it depends on some other factors; how much smoke is it and how long it lasts, how the car runs otherwise, any vac leaks etc.

Make sure your air filter is clean, as well as your MAF sensor. You can GENTLY clean the element with some rubbing alcohol and a cotton swab.
Could be a million things making it run richer than it should...a leaking injector, TPS etc. (I'm leaning towards the leaking injector(s) but it's indeed a guess ).

Maybe others have better ideas. DAN H
 
plugs

have u checked your plugs?? when my tranny went bad i had to shift from 1st to 4th and i would give it gas to pick up the rpms i ended up fouling my plug black smoke would come out on start up and it was backfireing a bit
 
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