Am I running Too Rich?

DCOP · 08-13-2007, 04:47 PM

My 2.7 with 40 IDA Webers runs great since it's rebuild about 1000 miles ago.
It doesn't smoke at all but it does seem to have a strong exhaust smell, like it's running too rich. It has a performance cam grind, port and polish and the carbs have also been rebuilt. Other than that it's pretty much stock. Any suggestions on what I could try without a lot of carb tuning and testing equipment? Is it as simple as trying new jets? Not sure of current jet size. Obviously I don't want to lean it out too much. Thanks in advance. Darryl

azasadny · azasadny's Garage

Darryl,
Do you get any popping/backfire from your exhaust?

RoninLB · 08-13-2007, 05:18 PM

even the car riding behind me says my car stinks of gas fumes.

azasadny · azasadny's Garage

Same here...

DCOP · 08-13-2007, 06:20 PM

ArtZ,
Get a little rumble and popping from the exhaust when downshifting and slowing down but no backfiring throughout the shift range, once warmed up.
Could just be the nature of the beast!

RoninLB · 08-13-2007, 06:23 PM

if i don't get the rumbling and slight popping from the muffler i'm too rich.

911s55 · 08-13-2007, 08:19 PM

Darryl; What spark plugs, type and grade of fuel are you using?
David

sammyg2 · 08-13-2007, 08:33 PM

Do an internet search about the procedure for reading plugs. Or learn from an old school guy like I did.
Or, ... buy an LM-1 or such with a wide band O2 sensor and monitor it. the only problem with that, you need to tune two carbs and they need to be the same. If you have two into one exhaust you will end up tuning the average between the two. But if you use that method along with reading plugs and a good syncronizer for idle adjustment/mixture you will get it pretty darned close. That is, unless the temperature outside changes or you change altitude or the humidity changes or you clog an idle jet or .....

If you run webbers you need to get good at this stuff or you need to pay someone $$$ to do it for you or you need to live with a car that isn't tuned just right sometimes.
Carburetor is a french word that means compromise

azasadny · azasadny's Garage

I can live with the "poppity-pop-pop" from the exhaust when deccelerating. It's much better then the CIS backfires I used to get. The sound and feel of the Webers makes up for the popping and strong fuel smell, I'll live with the "compromises"!

kach22i · kach22i's Garage

Sounds like you are not burning all the gas you are getting.

At the risk of burning out your coil have you ever tried a larger gap than .028"?

Try .030 or even .035 all the blat..blat..blat goes away.

New plugs (NKG solid copper) never hurts at $2.00 a piece.

azasadny · azasadny's Garage

George,
The car runs well, with the exception of the popping through the exhaust and the fuel smell and I am leery of adjusting anything right now, maybe later in the fall I will. Thanks!