Captain Obvious

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...

Greg, From what I've seen, your bar sounds unfortunately typical. I sent you PM.

A lot of people complain about the 260 carbs. They are commonly known as "flat tops" because of the shape, and most people don't like them. Parts availability for the flat tops is difficult. You can get a "rebuild kit" easy, but if that doesn't fix the problem, then you're out of luck. The support structure just isn't there to supply other parts if necessary. If it's running fine, then don't poke that nest. However, if you have carb problems, unless you find someone in your area that is willing to work on the "flat top" 260 carbs, then you may have to switch to the older "round top" 240 carbs used from 70 through 72.

Yes, if you reach resolution, I'd love to hear it. I've still been thinking about it, and I took a good look at the damper tube under bright light and magnification. I didn't see anything that would contradict what we've already covered. The cavity is dead ended at the bottom, and what's happening to you should only be able to occurr through the top. What I was thinking I might find was that the damper tube wasn't one piece, but instead was made from multiple parts pressed together at the factory. My thinking was that any seams could potentially allow for a low end leak. I didn't design the thing, but for ease of manufacturing, I would have done it with multiple pieces. Much easier than creating a highly polished, deep, blind ended hole with a square face at the bottom. I would have started with tubing, already highly polished ID and OD, and pressed a plug into the bottom end that had been machined to accept the needle. However even under light and mag, I found no evidence of that. It's possible to have been designed in such a way that there are no visible seams, but I wouldn't know for sure unless I destructively disassembled one. I've got a parts carb, so I may do just that, but it won't be for at least a week. If there are multiple parts, it would open up a whole new family of explanations and solutions. BTW - This won't help any, but here's the other thread I was thinking about where there was a guy saying that he kept losing damper oil. As far as I know, he never reached resolution either: http://www.classiczcars.com/forums/thread43034.html

Yes, your understanding and description are correct. The tube is blind ended at the bottom and the only opening into that cavity is by way of the hole at the top. So barring defect or damage, the only way into or out of that reservoir is from above. I can picture three ways to get oil out of that blind cavity. 1) Evaporation - Which should not be happening to 20W motor oil 2) Check valve not passing fluid fast enough on the downstroke and lifting oil up and over the top of the walls - Which you tested 3) A crack or other passageway near the bottom of the tube that shouldn't be there - Very unlikely to be identical on both carbs I have seen motor oil "migrate" from one location to another, but it happens very slowly. If you take a metal soup can and fill it halfway with oil and put it on the shelf for a year, I swear that the outside of the can will be oily. Your issue is happening much too quickly for that though. I must be missing something...

I like that. So how are those attached? Is there a thread here somewhere where you talked about this install?

Pics when you're done?

Stalks out piston lifts easily and falls quickly is perfect. Stalks in piston has resistance lifting and fall is only slightly damped is also perfect. Not exactly sure I understand what you meant by not seeing spillage, but if you lift and drop the pistons without the stalks installed, you aren't testing anything. You won't cause any spillage or overflowing doing that. You need to have the stalks installed to do the lift and drop test. c1) Pull the stalks out and make sure the reservoir is filled to the correct level c2) After verifying that the oil is at the proper level, reinstall the stalks in their normal operating position c3) Stick a finger in the mouth of the carb and lift the piston all the way to the top until it won't go any higher - Should be hard to lift c4) Let the piston drop as fast as gravity and it's spring will allow - Should fall quickly c5) Repeat c3 and c4 ten times c6) Pull the stalks out and check to see if the oil level has changed. If the level has changed, there should also be fresh oil on the outside of the reservoir tube. If the level has changed and there's oil everywhere, make sure that all the brass jiggly bits are clean and goober free and everything that is supposed to move does. The top washer is fixed to the shaft (as is the C-clip obviously). The lower washer and the cylinder should jiggle. Also check the stalks? Do they appear straight? If you lay the stalks tits up on the bench, are the shafts perpendicular to the benchtop? One last question that I should have asked a while ago... Do you know if the engine has to be running in order to consume the oil? By that, I mean, how many days does it typically take you to accumulate 350-400 miles? And if you would happen to let your car sit parked for that same length of time, would the level change, or does the engine have to be running to cause the disappearing oil?

You don't want back pressure. You want momentum. Problem is that sometimes an increase in momentum is accompanied by an increase in back pressure. I'm no expert in the field, but my theory is that since an increase in momentum is often accompanied by an increase in back pressure, people started thinking that back pressure was the desired effect, and it's not. It's the unwanted, but often necessary, side effect.

Sorry... Meant to say there are two washers on the top and a C-clip on the bottom and the jiggly cylinder between them. Dropped some words by accident. I also wanted to explain the purpose behind the lift and drop test. You should be able to lift the suction piston all the way to the top until it won't go any further and then let it drop full speed to the bottom without any fluid loss. If the check valve is working properly and the oil is of suitable viscosity and level, then it should rush through the check valve fast enough that it won't pool on top of the valve enough to lift the oil to the point where it can escape out the top of the tube. If, for whatever reason (for example... too thick of an oil viscosity or something wrong with the check valves), the oil does not flow through the check valve freely enough when the piston is dropping, then you run the risk of lifting oil up and out of the tubes. Does that make sense?

Bummer. I was hoping that this was a non-problem and you were simply overfilling the tubes. It's been a while, but I remember someone else had a problem with dropping level in the dampers, but I don't remember if they ever reached resolution. I'll take a look for that thread when I get a chance. Take a look at the jiggly bits. There are two washers on the top and bottom and the jiggly cylinder between them. The washers are different between top and bottom, and if memory serves, the cylinder may be as well. It's unlikely that someone took them apart and mixed up the parts, but if your oil isn't seeping out the bottom and isn't evaporating into the air, then it has to be coming back out the top of the tube somehow. Here's some far fetched ideas... Maybe you have a crack in your suction piston near the bottom that is allowing oil to seep out? Maybe the piston was machined incorrectly and what is supposed to be a blind hole isn't and there's some passageway through to the top of the needle? And yeah, if you find any O-rings in there, definitely take some pics and call an audible!

I wasn't expecting that the jiggly bits wore out. While that is possible, I consider it very unlikely. I consider it much more likely that there's a goober in there affecting operation. Or the stalks are bent or misaligned. Or a previous owner took the check valves apart and got them back together incorrectly. Or hopefully... There really isn't any problem at all and the OP is simply overfilling the tubes all the way to the top and expecting them to stay that way. So, back to you Jetaway... What is it that makes you think you need to add oil? When you say: Are you filling the reservoir to the very top and then putting in the stalks, or are you filling the reservoir a little and then using the stalks as dipsticks until the level hits the fill-to line on the stalks? It takes a surprisingly small amount of oil to do this. The reason I ask is because if you are filling them to the very top before you put the stalks in, then you are overfilling the dampers. Won't hurt anything as the excess will simply be pulled into the cylinders and burned, but if that's the reason you think you have to keep refilling them, then what you've got here is a non-problem.

No, it is not normal. No, there are no O-rings involved. If you are losing fluid out of the dampers, the first thing I would look at are the little brass jiggly bits on the end of the damper stalks. Those jiggly bits are a one way "check valve" system that is supposed to impede the flow of oil when the suction piston is moving in the up direction, yet pass oil easily when the suction piston is moving in the down direction. This allows the suction pistons to rise slow, but fall fast. If those jiggly bits are stuck and not allowing the check valve to open properly as the piston is falling, then the oil will be lifted up and out of the top of the tube by the valve itself. Some things to check to verify proper operation? a) Pull the damper rods, fill the dampers to the appropriate level (should be a fill-to line on the damper rods), and re-install the damper rods. Pull your air cleaner cover off and lift the pistons by hand. They should lift slow, but fall fast. c) Lift and release the pistons a bunch of times and then recheck the oil level. The oil level should not have changed. If, during this test, you have lifted oil up and out of the tubes then something is wrong with your jiggly bits.

I used Viton. I'm not worried about fuel or the heat.

Butter smooth. No leaks.

Yup, I tried it and it works perfect! Heater core is completely cool with the lever all the way to cold, and as hot as it used to be when in the hot position. Much cooler cabin! Cooler cabin Simpler and cheap generic under dash hoses Easy future heater core replacement Easy future valve replacement Cheap ubiquitous valve About the cable throw at the panel vs. the throw at the valve... Originally, the cable movement length at the panel was a little bit longer than the max throw at the valve. So in order to take care of that, I made a new longer arm for the valve. The longer arm takes more linear motion to go between endpoints, and as a bonus, the force required to move it is less. I don't have a pic handy of the original arm vs. my longer one, but I'm thinking that the one I made is maybe half inch longer than the original. All in all, I'm happy with the way this turned out. I'm not 100% thrilled with the hose or cable routing in the engine compartment, but one of the big reasons I put stuff where I did is because I didn't want to cut any additional holes in the firewall and I wanted to make the whole thing reversible if necessary. If I knew it would work, I guess I would have been willing to make it more permanent right off the bat, but since I was making this up as I went along, I wasn't sure how it would turn out. If I were starting with a clean slate, I would try to move the valve down and towards the battery a little, but in order to do that you would have to cut a new hole for the cable as the stock hole is too far up the wall.

Hunt over. http://www.classiczcars.com/forums/thread46899.html Thanks for the creativity spark!!

The heater in my 77 always blew hot regardless of where I put the temperature slider and I tracked the problem down to a faulty water **** valve under the dash. I had the capillary style valve (http://www.classiczcars.com/forums/thread46448.html) and spent a little time looking into a direct replacement, but after spending that kind of "quality time" working under the dash, I decided that I never wanted to go through that again. So I changed over to a ubiquitous newer style water control valve which I relocated up in the engine compartment instead of under the dash. I grabbed a bunch of different valves from the junkyard from various Honda and Toyota products, trying to find one that had the correct flow direction, had the lever on the proper side, and opened when the cable "pushed" instead of "pulled". I kinda lost track of which was which, but I believe the one I finally used was from a 2000 Acura TL. Here's the valve I used. Flow direction is left to right when lever is on the side pictured, and it's CW to open again with lever as pictured. That means I can mount it on the return line from the heater core and it's push to open. Note that I also had to make a new control arm for the valve to get the ratios correct between between the travel distance of the control slider and the travel distance of the new valve: Here's a couple pics of the mounting bracket I made for the valve: Here's the whole thing painted, mounted, and plumbed in the engine compartment. I attached it to the mounting bracket for the brake lines and fed the control cable through an existing hole in the firewall. I believe this hole is where the vacuum line goes for the HVAC system on cars with A/C. The hole location was a little higher than optimum, but since I don't have A/C, this hole was unused which saved me the trouble of drilling a new hole only to find out that the whole project was a mistake: It wasn't a mistake! It works great and will be a breeze to work on in the future if necessary. One other bonus is how simple it is under the dash without the valve and all the associated hoses:

I'm suspecting it's even worse than you imagine... From your other thread, you set the needle depth using the "jet-push-piston-home" technique (which isn't the right method BTW) and ran the car like that with no turns down on the nozzle? If that's the case, then that means you were actually idling the car with the needle shoulder pretty much resting on top of the nozzle. The only reason the car even idled at all was because the needle shoulder was mostly capping the nozzle hole. The tapered part of the needle wasn't metering the the orifice... The shoulder was. I'm gonna check the fiche to see if all years call for the same nozzle P/N.