Captain Obvious

Bugs me too. It's just so open ended... I'd pay the shipping for you to send them to me for yet another set of eyeballs, but I can't believe there would be anything that I could possibly notice that wouldn't have been picked up by ZT. After all those pages of investigation, I just hate not knowing. :paranoid: Hey, now that you don't need those carbs to run the car, how about that shot of the SM's and the N27's next to the ruler?

Thanks Willoughby! You may have just saved me from "fixing" something that was never a problem in the first place! So the jury is still out on whether that bend is intentional or the result of a misfire. Glad I didn't jump the gun and start straightening it yet! Blue, Yes that gap appeared to be consistent to me as well when I was looking it over. I didn't measure it, but it eyeballed pretty even up the length of the side. That, and the consistency of the bend itself is why I was originally questioning whether the bend was intentional or not. So, I'll measure the side gaps, and if they're even along the whole side(s), I'll assume the bend is fluid dynamics black art. More news as that develops. Fastwoman, Yes, your dueling anvils make sense. I was just thinking that if nothing went sproing, it would be easier to adjust on the bench. Although, it seems I may not have to be doing anything with it. That would clearly be the best answer!

I'm sure your really really not supposed to do this, but... Can I take off the other side of the AFM to get better access to the vane? Might I even be able to take the vane completely out to work on it?

Mine runs fine at all throttle openings, but I believe I'm running a little rich. However, I'm still very new with the car and haven't even had the opportunity for a decent shakedown yet. I've been finding and fixing the problems as I discover them and haven't gotten to the point where I'm ready to really start "tuning". I believe my AFM has been tweaked by the PO, and that may be why I'm rich. In other words... If I put the AFM back to stock I may end up lean. Yup. I'm sure it's cast. At this point, I'm glad it's as flexible as it is. :surprised

Junk. I'll go $55 plus shipping. :pirate:

That's exactly why I wasn't sure if it was supposed to be that way or not. Fluid flow is weird stuff and since I'm sure these AFM's were highly characterized at the factory, I wouldn't be surprised if that feature was intentional. But unfortunately, it sounds like it's not. Crap. And that answers my next question of "OK, so it's bent. Does it really matter?" I was hoping that even if it was bent, it didn't have a great implication on how the car ran. Now I gotta do something about it... Only if you come over and help me tune the system afterwards.

Yeah, no kidding. The implications, as I'm finding out, are deep running. So not only am I finding blasting grit in places it shouldn't be, I've also realized that all of the original chromate plating has been blasted off the steel bits and has been replaced with paint. Looks great until the first time you wipe something with carb cleaner and take the paint off exposing the untreated steel beneath. I would much rather deal with a little dirt, grease, oxidized aluminum, and old chromate. Even if it's starting to fail in spots.

Nice. I want to convert my 77 up the 78 design for the crankcase venting and AAR because I think it's a better system and should do a better job of keeping the AAR cleaner inside. One of the things that I don't have is the rubber hosing, and I agree with you that your design looks better than stock. I think I may plagiarize. Errr... I mean "flatter".

So I'm giving my AFM the once over before putting it back on and I notice that the air metering vane looks odd... Here's the outlet side with the vane closed: As you open the vane you can see that the bottom edge of the vane is not straight: So I'm guessing that it's not supposed to be that way, and it's bent as the result of a backfire into the intake or something? And simply for posterity, here's a pic from the intake side:

Thanks for the parts digging guys. I'll probably go the used route before resorting to buying new. Don't get me wrong about my PO. It's not like he blasted the inside of the throttle body. It's clear that he at least tried to keep the grit out of places it shouldn't go. Problem is that even if you're careful, grit sometimes gets where it shouldn't. So, it's not like I'm expecting to dump a spoonful of grit out from inside my BCDD, but it only takes one bead on the sealing surface of the valve inside to screw it up. Do I think there's a spoonful in there? No. Do I think there's a piece or two in there? Absolutely.

I like it. I'll probably do that once I work out the simple bugs. Nice broken exhaust manifold bolt.

Haha! Weird isn't the word I would use... :stupid: So far things are going pretty well. This whole thing started with me removing that extra throttle return spring you noticed. Once I took off that extra spring, I discovered that the throttle would not always return to min. So it seems the previous owner put on that extra spring to fix the return problem, but in fact it was a band-aid and didn't address the root problem. He added more force but didn't fix the real problem in that it should not NEED more force. After cleaning out all the grit, my throttle body movement is smooth and with the stock return springs, I get a good positive "clink" onto the idle stop each and every time. The linkage from the throttle body to the firewall is smooth and free turning as well. Now that it doesn't take excessive force to close the throttle plate, I will take your advice on adjusting out all the slop in the pulling direction. My return springs now be able to do what they are supposed to.

The whole host of issues? I just put some details in my throttle linkage thread http://www.classiczcars.com/forums/showthread.php?45815-Throttle-Linkage-Improvements&p=395674&posted=1#post395674 But the summary is that I've discovered that my previous owner got overzealous with the bead blaster and sprayed things he should not have. Here's the host I've found so far: Blasting grit in the throttle body and TPS making the throttle shaft movement grainy. Blasting grit making all of the throttle linkage ball and socket joints sticky. Blasting grit in the sleeve bearings where the throttle linkage mounts onto the intake manifold. Blasting grit inside the plastic spherical bearing where the throttle linkage mounts to the firewall. Not related to my throttle issues, but I found blasting grit inside my distributor as well. So what made me start looking at the BCDD? To be honest, I don't have any performance reason to believe there's anything wrong with it, but with all the grit I've found elsewhere, it is impossible for me to believe that it didn't get inside the BCDD as well. But I don't want to open it up without replacement parts first. If you open one, I'd love to see pics. I think I've got a pretty good idea of what's inside, but without opening one up, it's simply speculation. I just hope he spared the AFM.....:sick:

Thanks for the tips guys. This whole thing started with a hunt for an issue where my throttle would sometimes hang up just a little bit and I would have to blip it to get it to return to the low end idle stop. I started at the front end with the throttle body and have been working my way towards the pedal and have found and fixed lots of problems. I have also figured out what's going on... All of the issues I've found stem from the root issue that my previous owner got overzealous with the bead blaster and hit everything. The car sure was clean when I bought it, and now I've begun to understand why! :mad: So I had glass beads in my throttle body and TPS making the throttle shaft movement grainy. I had glass beads making all of the ball and socket joints sticky. I had glass beads in the sleeve bearings where the throttle linkage mounts onto the intake manifold. I had glass beads grinding away inside that plastic spherical bearing. Anyway, everything else has cleaned up pretty well and doesn't seem to be badly worn with the exception of that spherical bearing at the firewall. I guess I'll clean that part up as well and put it back on and see what happens. On a related note, I figured out why I wasn't getting full advance on my distributor. Yup... glass beads mucking up both centrip and vacuum advance mechanisms.

Does anyone make an improved version of the throttle linkage between the firewall and the intake manifold? Here's the part that I'm talking about: I'm chasing sticky, non positive throttle action and have found that my throttle linkage is sloppy and worn at the plastic pivot up by the firewall: I know I could clean and lube it to fix the sticky part, but that won't do anything to fix the sloppy part. Are there aftermarket options out there or am I looking at a custom repair?

I have verified that my solenoid valve pulls in when I apply power to it, but I'm not convinced that the valve makes a great seal. I can certainly tell a difference in BCDD operation between when the solenoid is pulled in or not, but I've got some internal leakage and I can't tell where it's coming from without taking the BCDD apart. Problem is that I sincerely doubt that I'll be able to split the BCDD parts apart without completely ruining the diaphragms. In other words, I'm not past the point of no return yet and I didn't want to pass that point until I had a "plan". Blue, this is your fault by the way... :laugh: It all started by looking into that goofy auxiliary throttle return spring that you pointed out to me and has spiraled out of control from there. I've been trying to figure out why that additional return spring was needed to get the throttle to return to idle and I've discovered a whole host of issues that are contributors. One of the fixes (so far) was to completely disassemble and clean the throttle body. With the exception of the BCDD or course.

Fastwoman, Where did you get the tube that connects the valve cover to the throttle body? Is that copper sweat tubing?

Be careful with the mounting bolts... It is not uncommon for them snap off leaving the threaded portion stuck in the aluminum. Turns a simple fifteen minute job into an all day swearing affair.

Haha! Yeah I saw that too, but... So? If they didn't want me to take it apart, they wouldn't have put screws on the bottom. Seriously though, I suspected as much. Most discussion I've seen on the BCDD is people talking about how they have disabled them, not repaired or replaced them. I just figured I would throw the question out there and see what stuck. Was thinking (hoping?) that maybe one of the aftermarket specialists might offer parts.

24 hrs and not a peep... So, I'm guessing that's a "no"?

Are the two diaphragms used inside the BCDD still available?

Put a filter on it and prime the oiling system before you try to start it. If it were me, I would also pull the valve cover back off while priming to verify proper oil flow to the cam lobes. Unfortunately the priming process requires you to pull the oil pump back off. I just went through this on my engine and here's my experiences: http://www.classiczcars.com/forums/showthread.php?45440-Priming-New-Oil-Pump-How-to As for your leak at the pressure regulator plug... Yes, it should be as simple as changing a washer. However, when you take the plug out, look for scoring or deep scratches on the underside of the plug head and on the mating surface on the pump body. Just in case the problem isn't the washer at all.

Glad you got em replaced. Only thing worse than working on old rusty stuck in place suspension bits is working on old rusty stuck in place exhaust bits. :sick: Did you do anything to try to preserve the alignment to get it to the shop? I ask because I've seen tires ruined in just a few miles if the alignment is really off. Unless the shop is right down the block, you might want to stop a mile or so from the house and feel the tire treads for heat. If they're really hot on one edge or the other, than you might be at risk.

Heh. Sounds like I should take a look at ebay for a better scope. The hardest part about taking that pic was figuring out how to get the camera and the scope to play well together. It's a ten-fifteen year old analog scope while the camera is a two year old decent quality one. In other words, with a quick decent quality camera and a non-storage scope with very little natural persistence, the camera was too fast for the scope. All I would get was a single dot where the trace was at the instant the "shutter" opened. I had to get into the cameras settings and manually slow it down to a longer shutter opening to get a pic of the trace. I wish I had a digital storage scope...

The aftermarkets that are in there now are an off-white orangey pinkish kinda color. "Salmon" would be the best description. They aren't white. They aren't pink. And they aren't orange. But they have tints of each. The lead wires coming out of them are white if that helps at all. I looked them over (installed) and didn't see any markings. I'll have to take a better look once I get the car out into the daylight. Haha!! And Lenny, I couldn't have put it better. That's exactly what I'm worried about. I don't know just how power hungry the PO was, but it's clear that he was looking for something, and although most of his work has been satisfactory, I'm always a little suspect. I worry that he overcompensated for something that didn't need to be fixed in the first place. "Slightly" I've got a minor rich condition and I haven't spent a lot of time hunting it down yet, but figured I would gather information and study first just to make sure that I'm starting from the right place. I really don't want to pull the injectors and measure flow. I mean I could... I just don't want to.