Passed CA Smog but?

[1LowToy]

My 1980 I6 too lean. I can feel it too. First real drive since I've had it and just getting on the freeway can be chore. Anyone ever delt with that lil 2bbl carb have any ideas?

[1LowToy]

Ok so I'm talking to myself here. I tried blocking off the EGR and it does run better and no EGR serge. So how should I go about the problem.

1 Replace the EGR with the smallest orifice.

2 Rebuild the carburator and enlarge the main jets

3 Replace spark plugs with a much smaller gap or/and a cooler heat range.

[jared87350]

check your fuel pressure.
replace your jets if needed. could be a clogged jet.
if it has been a while rebild your carb, couldnt hurt.

[leegrady]

This is a very generic complaint. When troubleshooting always start with the easiest possible solutions. Like for fuel delivery make sure the filter flows freely. I take it the truck runs without missing, but lacks power. Here is a kind of basic breakdown that one could follow.

Road test and duplicate the complaint.

Visual inspection.

Hook up a vacuum gauge and see what that tell ya. Most repair manuals have illustration on what different needle readings mean.

Dry then wet compression test.

If compression test reveals a dead cylinder, or low compression perform a leak down test.

Cylinder balance test. You could do this before the compression test.

See you want to make sure everything is as it should be, and go through the motions even tho' you probably know it's probably not that.

Bad coil.

Timing sprockets and chain wear retarded. Check base timing, then centrifugal, then vacuum with a timing light with a built in advance gauge for total advance measurement.

EGR valves are used to dilute the air fuel charge to lower combustion chamber temp. to reduce the production of NOx (occurs 1600 degrees F. or higher) which when in the atmosphere produces tropospheric ozone (smog) when struck by ultraviolet light. The engineers usually allow two cylinders to be subjected to exhaust gas lowering the NOx production enough to keep the EPA guys happy. This dilution will only occur off idle at normal operating temp. From ported vacuum the line go to a temp. switch usually screwed into the intake manifold, and then to the EGR valve itself.
If the EGR is connected to manifold vacuum idle quality will be bad, if at all. An EGR serge is a symptom of vacuum oscillation and is not the root cause of low power. Ported vacuum is not going to pull the valve off it's seat until engine is warmed up, and running in mid range rpm's.

I would go through the carb' (dip it in carb' cleaner) once I threw a tune on it, and made sure by some of the above mentioned test that every things, every thang. Pay close attention to off idle passage ways, power valve, and WOT passages. Some of the accelerator pump linkage is a little tricky on those 2 barrels, but hey, if we can't fix it it an't broke.

Bone stock '81 GMC K2500 350Q-jet/sm465/corp 14 bolt rear/dana 60 ft.
'95 T-bird lx
Replica '65 Daytona Coupe stroked 351w eight single Holley toilet bowls w/ modified EEC-4/tremec tko 5sp/9'' ford w/detroit locker 355ratio 0-60 times avg. 3.4sec./1/4 mile 11.1/top speed 180 This beast will xlo8 harder at 130 than a police interceptor vicky will in first gear.