I have had a problem with the engine in my car running rich (305 lg4 cc-4BBL.)

thanks to all of you who have attempted to help me with this problem.

I have tried everything I and ya'll can think of and have had no luck correcting the problem.

if anyone comes across anything that may pertain to this please message me so I can check it out.


THANKS ALOT ALL !!!!

 

RedBird,

You're giving up way too easily. There are some rudimentary things to check on a carbureted engine in case of rich mixture.

1. Float level - too high or a sticking float can cause flooding and rich operation;

2. Fuel pressure - excessive pressure can flood the bowl;

3. Fuel inlet seat and needle valve - a leaky inlet valve can flood the bowl;

4. Main metering well plugs. These are on the underside of the carburetor bowl body, and the plugs are merely staked in place. These are always a point of suspicion on Rochester quads;

5. Mixture control solenoid operation and adjustment;

6. Throttle position sensor adjustment;

7. Oxygen sensor condition;

8. Secondary air valve position and operation;

9. Bowl body gaskets;

10. Damaged idle mixture screws;

11. Correct connection of all vacuum hoses and PCV operation.

And this is just a start. I'm not sure what you've done to this point, but those are always good items to check.

 

vader, thanks for the reply and some things to check.

I'll give a brief overview of what has been done so far:

1 float level set according to carb rebuild kit (recent)
2 fuel pressure not checked yet (new pump with new motor (4000 miles))
3 fuel inlet and needle (new with rebuild kit)
4 metering well plugs(J-B welded in place during rebuild)
5 mixture control solenoid(check as per Vaders instructions)
6 TPS checked per vaders instructions(ok)
7 O2 sensor (new with motor (4000 miles)
8 sec. air valves(adjusted per tech article(loosened spring and filed stop tang)
9 bowl body gaskets (new with rebuild)
10 Idle screws (looked OK at rebuild(visual))
11 All vacuum lines checked and rechecked( for position and connection)
12 vacuum at idle (rock solid 20" hg.)
13 checked vacuum sensor (4.97 volts at no vacuum, .64 volts at 20" hg)
14 checked baro sensor (.97 volts at atmosphere)
15 new thermostat (195*)
16 radiator fan comming on at 220* (per dash gauge)
17 new temp. sensor
18 IAB adjusted per dwell gauge (30 on the 6 cyl. setting in drive)
19 mixture screws adjusted to 2.5 turns out (set per vacuum gauge and tach.)


there may be more I may have forgotten but I think thats about it.

I do remember seeing a kink in the fuel line between the pump and the carb, but I don't think that would cause rich running, would it?????

I hope thats enough info for ya !!

 

RedBird,

Wow, you've pretty much covered it. If it's running rich in all ranges, I'd suggest setting the float a bit lower. If it is only rich at the bottom end (idle circuit and transfer) I'd suggest leaning the idle mix screws back to about 1½-2 turns and readjusting the MC solenoid duty cycle.

You've got a tough one, for sure.

 

its hard to tell if its rich all the way up, when I get on it hard I don't see any smoke from the pipes. I think its only at idle or off idle that it's rich.(exhaust smells like pure gas) but not alot of smoke. the only time I see any smoke is when I start it up hot, then once in a while I get some black smoke (a little) from the pipes which clears up right away.