Captain Obvious

I had the exact same issue on my car and I tracked the problem down to a bad damper stalk. First you need to figure out which is the good one... The good one is the one that is hard to lift. I know it's a subjective thing, but as a guideline, I would say "it should be hard enough to lift that it hurts a little and leaves a dent in your fingertip." The other one (the one that lifts easily) has a problem. Next, you need to figure out what's wrong with the damper: a) Measure the outside of the two dampers with a micrometer or a set of calipers. They should be the same (probably are). Under magnification, look closely at the brass jiggly bits on the bad one. Look for gouges in any of the surfaces or goobers of crud stuck anywhere (doubtful). c) Under magnification, make sure the arrangement and orientation of all the jiiggly bits is the same between the two (probably is). d) Stand the stalks on the workbench knobs down and check that the stalks are perpendicular to the workbench surface. (This is what caused my problem.) In my case, everything was clean and assembled correctly, but one of stalks was not perpendicular to the knob. This causes a problem because when you screw the stalk into the carb body, some of the the brass jiggly valve bits at the bottom of the stalk will not be in correct alignment and the check valve won't seal when lifting the piston. I replaced the entire stalk and the problem went away. The insidious part to this is that everything looked fine at first glance and it wasn't until I really studied the system that I figured out what was going on.

Well, if it's any hint as to the age of the version used, the install docs talk some about Win 2000. What does one need to do to get new versions regularly?

So the Honda blower moves more air. I get that. But I'm curious as to why... a) Does it move more air because it's a newer better more efficient design? (Thinking maybe better motor or impeller technology?) Or, Does it move more air simply because it and spins faster than the original and draws more current accordingly? The question is... Is the increased air movement "free" due to technological advances, or do you have to pay for the additional air with more current to the motor?

I downloaded my copy from http://www.xenonz32.com/reference.html. That's the one that ran on my old XP machine until my machine went belly up. I don't remember what version it was, and I can't use the old machine to check... Any idea what version that is at xenonz32?

SteveJ, That would be awesome. Could you please check for compatibility running under straight Win 7 before you run it under the virtual XP? I believe EuroDat had a problem under Win 7, but who knows... Maybe it might not happen to everyone?

Thanks guys. I had looked through the manual and the fische and didn't see any retainer of any sort, but you never know. The zip-tie sounds like a great idea while I'm in there though!

So you tried it on your Win7 laptop and it did not work? I really don't want to start messing with virtual machines. I've avoided it to this point in my life and I'm not itchin to start now. Although... I've got a Win 3.1 program that I really miss. It worked fine up until the transition from XP to 7.

Is there supposed to be any sort of clamp or band around the innermost shifter boot to hold it into place, or is it just a snug fit alone that does it?

Does the FAST software work with Windows 7 ? Before I bother to take the time and space to install only to find it doesn't work...

Are those the ones they call "Basket Weaves"? I've got something similar on my car, but the area out where the weights would go is a little different. I've got a wider sloped section. I'm still trying to figure out if I like them or not. On edit... I found a pic of the similar wheels like I have. From this thread http://www.classiczcars.com/forums/thread45953.html: Darn it... Cant figure out how to attach a previously attached pic so that it comes up with a thumbnail with an embedded hyperlink. :stupid:

Yup. That's why I bought one. I was working on a 74 at the time. But..... They were wrong. It wasn't for 73/74, it's for earlier. And the needles are wrong for any year.

I surely won't claim to have seen them all, but every carb cleaner I've ever run across is highly flammable. I'm not talking about the engine degreasers... I'm talking carb cleaner. Mostly acetone, methanol, tolulene, etc. And for the shaft leakage... As designed without a pliable seal there, some leakage will naturally occurr. But as long as it's not "excessive" you don't have to do anything about it. There's others on the forum with much more carb experience than myself, but my read on it would be if you can tune the carbs at idle without having to go some unusual amount of turns down on your nozzles, your plugs look good, and you're getting good power while driving, then I wouldn't worry much about the throttle shafts sealing.

I thought the expectation when you sprayed carb cleaner near a vacuum leak was that the idle would go up, not down?? And I would guess that vacuum leaks around the throttle shafts wouldn't have much of an impact at highway throttle positions. I would expect that even if you were getting some air past the throttle shafts, it might have a big impact on IDLE, but once you cracked the throttle plate enough to maintain highway speeds, the impact of that leak would diminish. I mean, you never WANT that leak, but it's impact goes down as the throttle position goes up. A little late now (as you already figured out), but I don't think leaking throttle shafts are making you run hot on the highway.

I believe they used SU's on some of the Volvos, so if he's got old Volvo experience, he should know his way around the Z carbs. Only question though would be is he capable of making the leap from the round tops to the flat tops like what you have... They are the same carb in theory of operation, but there are a few differences. That list I put together was assembled with an attempt at "all things considered". By that, I mean, I tried to put together a list of things that wouldn't cost much, wouldn't be very difficult or require special tools or equipment, and wouldn't take too much time at any one sitting so you could still use the car as your DD while working on it. My intention was not only to get you some possible improvements in how well the car worked, but also an expectation that you would get some experience and knowledge while doing that work. You could spend hours and hours and hours on making things perfect, but I know it's probably not the right time for that. Once you know your way around the car and have a handle on the FSM, you get to spend countless hours working on everything else! If it's running well once warm, isn't billowing black clouds, and has decent power, then you're doing as well as a lot of Z owners. Haha! It's amazing to think how "spoiled" we are with todays cars... You get in, turn the key, and hit the road. I typically start the car cold in the morning, and have wheels turning no more than ten seconds after the starter has stopped spinning. No muss, no fuss... It just starts and goes. We take it for granted now, but when you think about it, it's really amazing!

Apologies ahead of time if I'm wrong, but I'm gonna go out on a limb and make some age related assumptions. I don't know how old you are, but I'm guessing that every car you have ever seen or been in to this point had computer controlled fuel injection systems and no choke. You got in - turned the key - and went off down the road without a hiccup. Well let me tell how it used to be in the old days... There was no electronic fuel injection or computers of any kind in cars. Cars had carburetors and chokes. When you first started your cold carbureted car, it ran "OK" if you were lucky, and "poorly" if you weren't. If you were lucky, you could let it sit at high idle for a minute or so to warm up before you went off down the road, and if you weren't lucky, you had to sit there for a minute and nurse it to keep it running. Then once it was running well enough that you felt confident that you could pull out into traffic without stalling in front of someone, you could get moving on your way. As you put a few miles behind you and the engine continued to warm up, it gradually got better and better until it ran "good". The best you could ever hope for was that it started easy, idled smooth but tentative while cold, and improved quickly to the point where you were safe to leave your parking spot. So what would I do? With the FSM as a guide, I would start with the easy stuff: Ignition - Install new distributor cap, rotor, plug wires, and spark plugs. While you're in the distributor, check your ignition pickup gap. Once you have installed new components and verified your pickup gap, check your ignition timing and adjust as necessary. Fuel - Check and adjust your damper oil as necessary (yes, you have a fill-to line on the damper stalk). Check your float bowl levels. I would assume that if your float bowl levels are OK at idle and you aren't running out of power on the highway that your fuel filters are not clogged (yet). Air - Replace the air filter and inspect all the vacuum hoses and lines in the bundle of snakes and compare against FSM for correct locations of all the tubing. Vacuum leaks are not your friend, and because of the complexity of the 260's system, there's lots of opportunity for them to occur. Keep in mind that this is just the simple non-invasive stuff. Beyond that are more invasive tasks like setting the valve clearances and replacing the fuel filters. Also keep in mind that I'm focusing on simple "performance" based stuff, and there is a lot of "safety" related stuff suggested earlier by SteveJ and LeonV like brakes and suspension inspections. Keep us posted!

Problem is that you've got no "baseline". You don't have any portion of the car verified, tested, proved positive, that you can be completely confident is working as designed. What I mean by that is, for example... Stuff like a short lived dead spot, "bogging" on heavy acceleration as you described above could be caused by a whole bunch of things. Some carb related, some not. Could be anything from lack of oil in the carb dampers, to a clogged fuel filter back in the electric pump, to a distributer problem. Might be fuel related, might be ignition related, might be air related. Could be anything. Point is, either you better get good at opening your wallet, or you better get good at finding and fixing your own issues. So back to the carbs... The flat tops work great when they're working great. I'll even risk poking the hornets nest here and go out on a limb to claim "Better even that the round tops." Problem is, as with many other "better" systems, that improvement comes with the down side of complexity, and that complexity provides more avenues for problems to work thier way into the system. The bottom line is, either carb choice works great if done properly, but the round top system is boatloads simpler than the flat top system. That simplicity makes it much easier to keep the round tops working properly and also to troubleshoot problems when they do occur. I know the flat tops pretty well. But reaching that point is much easier to achieve if you aren't behind the eight ball working on your daily driver!

Speaking of EGR, one of the things that can cause the problems you're describing is if your EGR valve is active when it shouldn't be. The EGR valve should only be open after the engine has warmed up, and if it opens before that, it can cause rough running. To check for that, pull and cap the hose running to the EGR valve (the thing with the large round cap) and see what happens.

Your cold start and running issues don't surprise me at all: "In 08/11/08 it had all the hoses replaced, repaired the choke and cleaned out the carbs and had 83,520. I bought it with 83,760 on Friday." Sounds to me like the previous owner was chasing a performance problem with the car... He had all the hoses replaced and the carbs taken apart and cleaned out four years ago, and then put less than 250 miles on it since. I assume it's been sitting with the same gas in it for those four years? I'd be happy that it runs at all! If you're looking for significantly better performance that what you're getting now, you're probably going to have to get inside the carbs. Or open your wallet and find someone near you who's got a handle on the infamous flat tops and hope that it's something simple that can be addressed by the anemic rebuild kits. If you were closer to me, I'd be happy to help you with them, but I'm several hours from you. Also, from one of your previous posts, there's a question that hasn't been addressed: Under that cap is your EGR valve. I'll second the guess that you've got an exhaust leak. Probably at the rear of the engine back by the firewall.

I took apart a reservoir tube from a flat top and verified that it is made up of multiple pieces. Unfortunately, I don't have a round top piston that I'm willing to autopsy, so I cannot definitively say that the round tops are multiple pieces as well, but after seeing how they did the flat tops, I bet that the round tops are multiple pieces too. I can now theorize possible fluid loss through the seams between multiple pieces plugging the bottom of the reservoir tube. So, if you are in fact losing oil and it's not your imagination, that may be where it's going? Here's some pics of what I did. Flat top piston on left, round top on right: Bottom of flat top. You can clearly see the seam line between multiple pieces: Bottom of round top. There is no seam, but the diameter is smaller than the OD of the tube. In fact, it is the same as the ID: A few seconds on the arbor press, and the flat top tube is out and apart: Anyone have a beyond help round top piston that they want to donate to the cause?

Auto or manual trans? If it's an auto trans, maybe your advanced points are OK, but your retarded points have a problem? Runs OK at first, but as soon as it warms up and switches to the retarded set of points, it dies?

Forgot about this part... I'm not really sure what problem you're identifying with the above, but I'll take a guess. if you're trying to figure out why you're seeing too much shoulder when you use the "leave the lock screw a little loose and push the piston down onto the jet" to establish the needle position, it's because you've got the mixture screws turned down a few turns to where they should be to have the car idle properly. Those two or three turns down on the mixture nuts will hold the nozzle jet down and that will add to the length of exposed shoulder when you use the "loose lock screw" method because you're using the nozzle to push the needle into the piston. The more turns on the mixture nuts, the farther down the jets, and the more shoulder you will end up having exposed. Is that maybe what you're talking about?

Foot in mouth, I just checked, and I don't have the 71 manual. Oldest I have is 72, but the needle setting procedure is the same. With that in mind, I've included page EF-28 (Engine Fuel) of the 72 manual below. A little hard to tell from the blurry scanned pic, but you should use a straight edge to set the shoulder of the needle even with the bottom flat face of the needle. Don't set it to the depth of the narrow groove in the center of the piston face. Set it to the large bottom-most portion of the needle. In other words, If you pull the needle out of the piston completely, and then set the piston needle hole side down on a flat table... The surface that contacts the table is the surface you should use to locate the needle shoulder. If done correctly, you should be able to see a small portion of the needle shoulder sticking out of the bottom of the piston when you're done.

The factory manual says you should use the straight edge along the bottom face of the piston to locate the shoulder of the needle. The shoulder should not be higher than the bottom of the piston... It should be perfectly even with it. If you post what year are you working on, I can point you to the correct page in the manual.

You're right about universal mysteries. I'm not quite ready to give up on this one though. Not until I cut one open. :ogre: I've seen that same note in the FSM about checking the damper oil, and I agree about the implication. I'm thinking that it's just prudent to check it every now and again. Shouldn't have to add any, but still prudent just to check? Perhaps oils in the past were a little more volatile than they are now? Maybe there's a tiny bit of evaporation when hot, and maybe that evaporation used to be more prevalent in the past with less sophisticated additives? Just musing ideas...