Excellent advice as always Bill. I’m going to re-read that multiple times for sure.
I’m getting 18.5 mmhg vacuum at idle, and that’s with everything vacuum-based connected except the headlight system. I disconnected it to have a port to measure vacuum while adjusting idle mix and rpm. Got the idle set great, both screws ended up fairy close to 1.5 turns out from full in (not cranked down hard, don’t worry!) which from what I read is typical. When I reconnected the headlight system the idle rpm dropped a little and got a little less smooth, not horribly but enough that I assume it’s affecting performance/rpm in the name of bells and whistles, so for now I’ve capped that port and left the headlight vac disconnected until I can get a mityvac and try and isolate any issues.
You have a vacuum leak through the headlight system. You will need to resolve this to get the car to run right when connected. A vacuum leak causes the idle mix to go lean.
Brand new check valve purchased from WCCC and installed a couple weeks back, to replace the shot one that was in there, but the problem persists.
The check valve is a one way valve that keeps the vacuum tank from emptying back into the engine. It has little effect at idle, mostly it keeps you from stalling when you take you foot off the gas.
I believe the headlight actuators are leaky because I can open and close them with my thumb over the main headlight vac line that was connected to the manifold, so that means they’re leaky in at least one direction (depends on how the headlight switch was set - in this case off) right? Or am I misunderstanding there?
Sounds like you are on the right track to find the leak.
Plugs, I don’t know the age, and I’ve never opened up the distributor, so both could be culprits for sure. I’d like to replace the plugs as a matter of course, just because I don’t know anything about them and it couldn’t hurt. The distributor, it seems like the MSD is pretty popular and eliminates the points concern, so is probably worth doing? Is there a reason not to do both of these, for a car that’s intended to be a driver not any type of show car?
Replace the plugs and replace the points with a Pertronix electronic ignition. The Pertronix fits inside the existing distributor. You need to hook it up properly, but it is really pretty easy, and you will never have to mess with the points again.
The fuel filter sure isn’t a bandaid, right! The fact that it was run for who knows how long without any fuel filter is of course a bad omen. And for all I know the tank and lines are original and full of flaking shellac and rust and all that. I love the coffee filter idea and look forward to doing it. Well, I don’t look forward to the results I expect, but I’m eager to do the test.
The stock carb had a fuel filter at the inlet, the Edelbrock does not. So adding a filter is a good idea. However, the primary filter is inside the gas tank on the end of the fuel pick up tube. If it is original, it is probably laying in the bottom of the tank or otherwise compromised. The fuel filter IS a bandaid if you are trying to use it to filter out rust. First off, rust won’t be stopped, and second the bigger problem of shellac being dissolved from the inside of the tank won’t be helped at all.
The pressure regulator is a bit of a bandaid, but, with the spec for the pump being outside the range of the spec for the eddy (and my pump being a brand new modern replacement) it’s not a bad idea is it? Or is it?
You don’t have a problem with fuel pressure so it really won’t do anything at all. If your fuel pressure was too high it would be flooding the engine by blowing the needle off it’s seat and over filling the carb with gas. All you will do is introduce two more places for potential fuel leaks. Sorry about that…
I have no clue how dirty the carb may be. I’ve got some pics looking down into it if there’s anything that might be an indicator to you of a problem.
Nope, you need to take the top off.
Is spray carb cleaner worthwhile? If it’s worth doing… I’ve never done it, is it just, RTCS (read the can, stupid)?
I’ve also never checked the floats, though I’ve read multiple times that it’s something to do, is important, is often wrong even right out of the box, and is relatively simple. Recommended?
I’ve never pulled the top of a carb off before either, so all I know about carb removal so far is “don’t let anything fall in the intake or you’re in for major headache”. I wanna keep getting my hands dirty though, and gradually learn everything there is to learn, so I’m eager to do this kinda stuff. Anything critical to know about pulling the top off the carb to check the bowls? Or just look at the manual and have at it?
The Edelbrock is the easiest carb out there to work on. Just read the manual and take your time. I think there are about 9 screws you have to remove to take the top off. This will give you access to the floats etc. and also see if there is crud in the bottom of the float bowls.
And just as a data point for you, if it helps… The idle is smooth at 500-550 once warmed up, aside from the occasional “puff” which I would love to have a better way to describe. And acceleration is right on as far as I’m concerned, no drop outs or weird transitions with either mild or heavy acceleration, no ill-performing that I’ve noticed. It’s just the puffing at idle. If it wasn’t for that, I wouldn’t even be thinking about any of this stuff, I’d be focusing on getting the slop out of the steering like we talked about before.
500 to 550 in park is too low. In Drive it would be about right.
Thanks again. I’m going to go re-read that post a couple-few more times and make sure I’m digesting it fully.
Oh! And about the tank and line replacement… I know you have suggested it as a standard move to make with any 40 yr old car, and I have fully intended to do it, though a couple people have tried to talk me out of it, saying that replacing the lines is really difficult because of the routing and all that. Are they just being wusses? Does it involve any disassembly of the car beyond removing the connectors that hold the lines in place, removing em, fishing the new ones in place, fastening and connecting it all up? Does tank replacement involve more than just draining the tank, unscrewing and pulling it out, putting the new one in place and bolting it in, connecting the sender and line? This stuff sounds simple enough to me, well within the scope of what I can knock out in a weekend. Am I missing something? Are they wusses? Major disassembly, removing body elements, welding, any of that? I apologize if this is an annoying line of inquiry that comes up too often, and if there’s already a good post or thread or website that covers this stuff, if you could point me at it rather than rewriting something you already wrote, that would rule. I’ll do some searching as time permits, too, but that usually ends up with me finding 500 threads that mention tank replacement and don’t go into any of these details.
Tank and fuel line replacement are not difficult, no welding cutting or anything like that. You will need to put the car up on jack stands and remove the driver side wheel and may be shock. The tank is dropped in from inside the trunk and comes out the same way. The main thing is to drain it first, and I would recommend running the car as low on gas as possible to make this easier.
Thanks again, Bill.