rhalpin20

my car still has an exhaust smell to it (lean, I think). With dwell varying around 30 can a car still be running either lean or rich?

Thanks...

naf

iTrader: (7)

Yes, but it's unlikely.

The O2 only sees the left bank and a problem there could confuse it into richening the mixture but most issues will have the dwell pegged all the way.

One member here had a vacuum leak off of the manifold source that feeds the accessories that showed good, varying dwell but still caused an overly rich mixture. Try plugging that source and see if there's a change.

Chances are though that everything's normal and you're just smelling a bad cat or exhaust leak.

five7kid

iTrader: (14)

I'm not sure lean exhaust smells (but I don't have much of a sniffer).

A weak O2 sensor can tell the computer it needs to give the engine more fuel when it doesn't need it. If you don't know how old your O2 sensor is, it would be worth the few $'s to go ahead and replace it now.

Ozz1967

iTrader: (4)

Are you running headers or the stock manifold? Also, what temp thermostat do you have? Running headers cools off the O2 sensor. Also, anything less than 190* stat can have the effect of the 02 sensor not reading right because it doesn't warm up enough. This is my problem.

DoubleV

Agreed about O2 sensor cooling with headers, but not about the thermostat temp. Almost everybody I know runs a 180 stat on there CCC cars. Some even run 160's in the summer and no one I know has ever had a problem because the computer goes into cloosed loop around 135 degrees. In your case, it could be the temp sensor needing replaced.

rhalpin20

I want to drag this out and give 3 guess as to my problem but i wont. I am currently running a roller 350 block w flat-top pistons and an l69 top end. my problem was to much timing. took it down from 8 to 5 and now she's running like a champ. Thank you everyone for your replys. Naf, thanks for all of your postings. you have helped me on numerous occasions, one way or another...

thanks again everyone

Camaro305SB

OP are you running a catalytic converter? Lotta people mistake unfiltered exhaust for a rich condition....