You can try snugging up those torque screws on the top of the carb where your finger is, maybe that will resolve the dampness your pointing to. I don't think that is enough gas seepage to be your issue. Looks more sweaty then leaky. Is the manifold dry ? Is it stained a golden yellow anywhere ? Curious, Have you pulled any plugs ? Are they wet ? fouled ? Any smoke out the exhaust ? Plug condition can tell you a lot about fuel & carb issues. With the exception of everything "RED" there doesn't really appear to have a lot of aftermarket / bubba parts etc.

 

Thanks for the photo!

I thought that "V" notch in the radiator support was specific to 1982.

I don't know what the PO was thinking. That distributor should be fine, but that carburetor will not work well with it no matter what you do. You should either downgrade to an 80-spec Quadrajet (with electric choke), or just go with EFI or a Holley. Trying to get the 81 system to work while also making performance mods will be a frustrating exercise in futility.

Can you confirm what intake is under all of those surplus vacuum hoses? Your car has factory cruise control, and even the smog pump. Rare to see all of that.

Other low hanging fruit that you can do right now is to check for vacuum leaks. Plugging stuff is likely better than leaving it open or connecting the wrong thing. Does that distributor have a working vacuum advance? Do you know what your timing is currently set to?

 

The question is....is the MSD just the cap and coil (everything else below it original CCC)? Or has the distributor been changed? Start by checking that. What else have you done/determined so far?

You need to learn more about your system. You're going into it blind. Helpless. Get THIS book and read it. Everything you need to know is right there in the book. Or if you have the factory service manual for an 81 it's in there too. The factory service manual is real helpful to have. If you were thinkng of buying one (ebay)...just get that. It's got a lot of the CCC stuff in there. Start with figuring out what's been done. Check the grounds are all good (there are several). The answer isn't going to fall from the sky.

It's a really good system: The funny thing is, a lot of guys with carb'd cars get tired of dealing with carb issues, hesitation, running rich, smelly, rough...all that. I know, I have had (and still have) carb'd cars. I grew up with Carb'd cars. Just search here on carb issues, LOL. Yeah they're simple, but still come with their own issues. I get why some guys like them. But just the same, EFI is great too. Many wish they had an electronic system, or a 'partial' electronic system ...easier than the time/expense of converting a carb system over to an aftermarket EFI. Well....your car HAS that partial system. Just take the time to get it fixed. It'll run great and sit there and idle perfect all day long. When I got a 1981 car...back in the day, with the CCC...man that was nice! It just ran perfect. It was like a whole new ballgame! Of course a couple sensor issues along the way. I still have one of those 81's (besides the C3), which racked up 275k Mi on it very few problems. So it's a good system for being a good DD.

The problem arises when people get lazy and start shade-tree-engineering and bypassing stuff (like an F-ing MSD ignition system!!). If they'd just done it 'right' probably it would be good. So you might have to unravel other morons' crappy work. Lot of people bypass and goof up modern cars too. In fact, I just spent 2 weeks here and there undoing other people's crappy half-assed work on a vehicle. Why do people do that? IDK...laziness I guess. So, you can fix your system. You might have to undo a few things and straighten a few things out. But you're going to have to arm yourself with information. Honestly the manual is the best place to start. You could spend 2 weeks reading blogs and wasting your time posting on misc forums ...waiting for an answer that'll never come. Or invest 2 hours reading the GM manual and start figuring it out and have it resolved soon enough. Once it's running right it'll idle perfect all day long like an efi car.

Where to Begin: It's real simple: Start by figuring out the distributor situation. Is it the 'right' one? Is the coil the right one with the right hookups? If not, then you need to stop there and get figure that out. I'm guessing it probably is the right distributor since you aren't getting other faults (like timing). But the coil might not be compatible. If someone's bypassed the original distributor system, you're going to have to correct that.

If the distributor is 'good', Then go into the Code 51 related things: Check ECM connections. EProm pins/orientation, Body/Frame/ECM Grounds. Ground are important bc that's the electrical path back to your ECM. Even on modern vehicles, there are more grounds than you can shake a stick at! Seriously, don't poo-poo the importance of good grounds. Check the ground pin at the ECM. You can check vacuum leaks by spraying some ether (or use an unlit propane torch) around the top engine (not in the carb..but around the base and behind/front of it). As you squirt or wave the propane around if rough idle improves, you've got close to the leak. Besides hoses, carb base gaskets can separate, things like that. So you're smart to consider vacuum leaks. But that's not giving you code 51.

You're going to have to arm yourself with information and get your eyes in there.

 

looks like just a dist cap not new dist so he will need
carb, 80 model
dist, vac advance
switch for trans lock
if he got rid of CCC

I am surprised caty convertor ain't plugged running that rich

 

Don't forget a set of wire loams. With the wires crossed like that, it's probably misfiring like crazy.

 

Does he know what a PITA manually switching the trans lock will be? EVERY SINGLE time he drives it? If he cant fix the CCC, how do you think he'll be able to convert it ...and have it run any good? I think he should get serious about learning how the system works, or sell the car and get an 00's Civic..or C4. Something he can pay a tech to fix. An 81 is really quite nice when the CCC is working fine.

Yer forgetting .....a future buyer who looks at the car if/when he goes to sell it (if 'converted') and see's a stupid switch on the dash to switch the tranny, will see it's been bastardized, and hack it down on price. Or look elsewhere.

,

 

I have a trans lock in my 80. I raise my left foot, and the transmission input shaft revs are matched to the flywheel. I already suggested that mod on his other thread.

The next thing to do is pull that distributor cap and count the pins going into the HEI module.

Why does it matter if he keeps an 81 all original? All that matters right now is that the OP fixes it up and enjoys driving it. If there's a 7 pin HEI module under there, sure! Try to fix the original system. Otherwise, put the CCC and ECU bits in a box for the next owner to throw away.

 

I think his path to getting it to run better is a lot quicker if he fixes what he has. It doesn't sound like he's checked much out yet.

I just think of my buddy who's "converted" several CCC cars back in the day and they all ran worse and didn't get good mileage at all, after all the work and expense. Plus he basically made them POS's. Obviously the OP can do what he wants but I'm suggesting look into the problem before throwing the baby out with the bathwater. I'm not going to rip the entire EFI out of my pickup because it's running terrible.

 

I think he's already there, though. 6 mpg! An L81 (basically an L48 with that awful carb) should get 15 mpg, without needing a locked torque converter. If not a third pedal, a high-stall torque converter is probably the #1 mod you can do to that car after getting the carb and ignition squared away.

So the OP is maybe $1000- plus some tools and YouTube videos away from a well-running car. Perhaps less if the CCC can be made to work, but that will become a bottleneck if he makes any other mods in the future, so better to bite the bullet now.