So you had air injection at the headers or directly into the exhaust ports? In any event yes capping that is a good idea. Disconnect the retard and see what you think it's a pretty quick thing to do. You'll have to reduce the idle of course but not rebalance the carbs unless you've set the linkage up improperly in which vase a bit of idle stop screw adjustment on each will be required. That's not a big deal unless you've got that big sealed airbox on the carbs.
At the headers. I will disconnect it. Apparently the microswitch was never being clicked in at idle stop prior to me rebuilding the carbs because I never heard the solenoid kick on/off when I touch the gas pedal as I do now. The sound is subtle but I hear it. When I put everything back together I adjusted the microswitch to 'click' at Idle stop. No sealed box but I'm wondering why I'd need to adjust all idle stops when only one is controlling the entire linkage. The rest of the idle stops are backed out. I can understand maybe having to alter the linkage adjusters... I was planning on re-testing the airflow balancing again in the spring anyway. Thanks again, t
That's why I said "if you have adjusted wrong". You should have no problem. Once I have it dialed in I like to advance the rest of the idle stop screws so that they just barely make contact. The linkage can have some flex in it and of course as everything warms up it all changes anyway. That's why I said earlier, don't drive yourself nuts over this. It ain't modern FI. These Maserati V8s have an easy to do very nice linkage and set of carbs. My Espada is a complete nightmare by comparison. Twelve of everything gets old ... especially since I have two V6s and one V8 Maseratis.
Well I´m stumped. I tried again some more today, working from the settings/method I described earlier. Got it idling, but roughly, and despite being perfectly balanced across all carbs it would simply not start up when I disconnected the linkage - so as not being able to use the accelerator when starting. Should´t the car start fine and idle if the settings are anywhere near the ballpark and the engine is warm? So I figured I´d try the "standard" method everyone describes, closed all the air bypass screws, and set the throttle stop screws (i.e. idle speed screws) at 1 turn in from contact. Started the car (with gas) and worked to establish barrel to barrel balance, then adjusted the throttle stop screws to match all carbs so they flowed the same. A bit easier than the other method, in fact. Managed to get a decent idle, still rough, but stable at 900-1000rpms, sucking about 6kg/h air. Car was fully warmed up by then, so I figured I´d check and confirm that it would start that way before starting on the Colortune. The car would not start. Remembering the tips online, I opened the butterflies a little at a time by turning the throttle stop screws in 1/4 turn at a time until the car would start, which it finally did, after adding 3/4 or more turn to all screws. Of course by that time, when the car started, the idle was at 1500rpms, and increased to almost 2000 after a few minutes. At least it ran. So I dialed everything back down again, and re-checked the balance between all barrels, etc, and it was again stable at around 1000rpms, 6kg/h or so airflow. Connected the Colortune, and the car would not start. Note that I´ve been trying, as per all instructions, to start the car without the linkage attached. If I give it gas when I start, it usually can be coaxed to life, and then when it settles down after a few minutes (even when warm it usually takes a few minutes) it will idle. If I let off the gas too soon, it dies. I also tried adding half a turn to the idle mixture screws, thinking perhaps it was just not getting enough gas, but it still needed pumping to start, and idled worse. Too rich. I could smell gas in the exhaust. So I dialed it back down and tried a quarter turn in from the start point (1.5 turns out from seated), but that would´t start or idle either. What I´ve found is that at idle, there is a spark from the Colortune, but no combustion that I can see. I tried gunning the engine a few times as well as running it at increased revs, 2-3000rpms. When I did that, a clear light blue flame was easily visible. As the engine settled back down to idle, the flame disappeared, leaving only a spark. After having a think or two over the whole thing, I have a few ideas, but lack the experience to know what it is that´s going on here, and if I´m on the right track. Every tutorial describes tuning an idling engine, and that the engine should run within a wide range of mixture settings. One should start the (warm) engine without the linkage attached, and the engine should show combustion while idling in the Colortune. I can tune mine after getting it started and balance the airflow fine. But my car will not start at all without the linkage connected (i.e. without giving it additional gas/air on start), nor does it show any combustion when idling (I´ve only checked cylinder no 1, but notice that it also idles very lumpy and rough when I attach the Colortune, and continues to do so even when putting the spark plug back. This happens even when the engine has been idling better only minutes before while dialing in airflow between carbs). I wonder if what I´m seeing is in fact a timing issue. Is it possible that the spark at idle is "off" in time relative to the piston´s position in the cylinder? That might explain the rough idle as well as the lack of any visible combustion in the Colortune while idling, but visible on acceleration and higher revs. I know that most engines have a system to trigger the spark progressively earlier the faster the engine is turning, isn´t there something similar to ensure the spark is a bit slower when idling? Maybe that´s the issue here? Tony - I disconnected the choke mainly because it was in the way. I unbolted the bracket at the rear of the engine bay where all the wires are connected, those to the carbs and from the car. I left the electrical connector attached, it´s connected to the choke lamp on the dashboard. The entire assembly blocked access to the idle mixture screw on carb 1. Also, all info says the carbs should be synced with the choke completely off/disconnected, and I rarely use it anyway. I will reconnect and adjust it when done with the main job. The microswitch is connected, but I cannot hear that it makes any difference or does anything. I could try disconnecting it, I suppose. The breather hose from the cam cover to the air filter baseplate is disconnected and covered with a sock (don´t worry, it´s clean ;-)). It´s not blocked, I can see fumes/smoke coming out of it when the engine is running. The smaller vacuum hose that attaches to the same point is open and hanging in the engine room. I noticed the other day that the revs slowed down and the engine stalled if I blocked it, today I didn´t notice that it had any effect at all on idling. The air box is not installed, but still attached and laying off to the side on the fender. All of the work done so far is without the air box or trumpets installed, but I don´t see how that would affect any of this. Mike - I didn´t find any air leaks, and sprayed carb cleaner all around the base anybody of each carb in turn while it was idling. No change at all. The hoses from the rear of the manifold to the air pump and the "consumption" meter in the cabin both appear to be ok. This is a US spec car, with air pump, charcoal canisters and I had brand new high flow sport cats installed recently. In case any of that matters. Bob, you seem to have a handle on all of this, could you give me the dummies guide to ignition and timing? How can I confirm that everything is ok? I´m frankly a bit disappointed that the mechanic who had the car, and dyno shop, didn´t address this if indeed it is a problem. I paid them to go through and check compression, leak down, cams/timing, spark, etc. They found that the carbs were worn and old and needing a rebuild, which I´ve done, and they had adjusted them as well as they could at the time. They replaced the spark plug wires (two were´t working under load) and put new plugs in (judging from the plug color - matt black, I´d say the engine has been running a tad rich previously). I´d love to get them balanced and the mixture dialed in, but am unable to do so when the car refuses to start. So main question of the day: should a (warmed up) QP3 V8 start and idle with NO help from the throttle if the carbs have been synced and the idle mixture is in the ballpark? I don´t understand how I can get everything running pretty nicely, warmed up, but then when I stop the engine it will not start up again at all without me pumping the gas and keeping the revs up for a minute or two. Is there anything else that might be causing the problem I´m seeing, namely unable to start without giving gas (even when warm), and no combustion visible at idle? Thanks. There´s a new day tomorrow for more experimentation.
ugh! Sorry to red all this. I didn't do the colortune until after the linkage was installed and adjusted carb to carb with the flow meter. This will allow you to step on the gas to get her started but do the tuning while at an idle. I need to press the gas pedal on a warm engine to start it quickly. Even prior to touching the carbs. But never on a cold engine with choke on full. Also I plugged that small vacuum line AFTER the engine was hot and prior to doing any flow balancing or colortunning. If you plug it while it's cold you'll have trouble keeping an idle. Try disconnecting the distributor vacuum line and plug the port at the solenoid. I will do that permanently on mine as soon as I get the chance. But this might not be a good idea for the US spec. Certainty regarding that is above my pay grade. ;-) Hope this helps. t
What I'm about to post may come across as condescending to you but honestly, I'm just trying to help you escape this morass. Ideally I think you should get someone who's done this before to work along side you on this project. Preferably someone who has used a color tune and tuned a set of Webers. But any experience with multiple carb setups is going to be very applicable here. I've not used a colortune though I did buy one for my Espada but the plugs are very hard to access in that engine and thought of putting that thing in & out 12 times just seemed absurd not to mention the possibility of fouling all the plugs in the process. Having twelve at once might be nice! Access to the plugs on a Maserati V8 are easiest I've ever seen! You have your fingers on an awful lot of things at once here and it's bit unclear as to exactly what you are doing and what is disconnected/connected. That's why I think posting some photos would help. There are no vacuum connections to an air cleaner box. If you do have actual vacuum source lines open somewhere then you are mixing in extra air that is bypassing the carbs. Big problem. So let's see the photos and the the guys most familiar with this years QPIII hoses and stuff may be able to spot something wrong. I'd also leave the linkage on and make it loose. This will allow you to pull the throttle for starting but let you balance the carbs at idle. Once the engine is warmed up and the airflows equalized then lock that up. If you're getting rough idle at this point it's not because of air flow issues through the carbs in the normal route. No need to revisit that adjustment or remove the linkage. You've checked for leaks on the manifold and other places? Have your plugs become fouled? Why on earth are you using the color tune with linkage disconnected? SUBSCRIBE if you're out of freebie picture space.
Not condescending at all Bob, just plain good advice. I've checked for leaks, spraying carb cleaner at the base, bodies and hoses nearby. No leaks that I could discover. I think I was closer the other day, leaving the linkage connected but loose. Somewhere I got the impression that once it was set, one could remove the linkage entirely for the fine tuning, then reattach it and lock it down at the settings arrived at (it may have been the guy with the Jalpa in the YouTube video, I'm not sure). I did arrive at a really good idle both the other day using the air bypass screws, and yesterday using the idle speed/throttle stop screws. Both methods work. The problem was restarting the engine when warm, after installing the Colortune. Have only pulled one plug, it was fine, but with carbon/soot deposits, so the car has been running rich since I got it back from the respray, when new plugs were installed and the carbs adjusted. Will check the others today, as well as disconnect the microswitch as Tony suggested. Will order a subscription today and take a few pics to post. I've already shot some iPhone video to put up on YouTube, and will link to that as well. I appreciate your comments.
Didn't have time today to do much else than snap a few pics. Obviously, even to me, I'm on the wrong track. So it's time to review my notes and the how-to guides and start afresh. I think I need to verify that the air pump is disconnected, either by removing the belt or disconnecting the two hoses mentioned in the manual (on my car there is a huge bundle of multiple hoses, I don't know which are the two needed). That will affect idle. I also need to disconnect the microswitch under carb 1, there's a molex there I can unplug. Can anyone point me to the two hoses to be disconnected, mentioned in the manual? Then I need to follow the service manual (which pretty much parallels what's been given here and elsewhere) and do it again from the beginning. Pics showing: 1. Carbs installed, linkage in place but loose. Nice and shiny and clean. 2. Disconnected choke assembly bracket, because it sits directly in front of the idle mixture screw of carb no 1, I couldn't get a screwdriver in there with it in place. 3. Engine bay - everything is still connected except for the small (vacuum?) hose that goes to the bottom of the air filter and larger crankcase breather hose. 4. Closeup of carb no 2, driver's side - the transmission kick-down armature is directly in front of the idle mixture screw, and although not obvious in the picture it's at the exact same level as the screw, making it neigh impossible to get a screwdriver in there. 5. Closeup showing small (vacuum?) hose and breather hose (covered with a sock). I checked all the vacuum hoses for leaks, they all appear to be fine. Reviewing at the videos I made, when using the air bypass screws to dial in the main idle and leaving the throttle plates completely closed I ended up with a pretty smooth idle at 4kg/h airflow. Doing the other version that most everyone recommended - closing the air bypass screws (except for inter-barrel balance) and using the throttle stop screws (aka idle speed screws) resulted in 6.5kg/h airflow at idle. I don't know if the difference is important, but do note that the online resources (Birdman308 Ferrari and the Lambo Jalpa guy on YouTube) are closer to 4 than 7 at idle. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Guess I posted the wrong pics, didn't get any replies. There is no one locally that I know of who has done this before or can help me, which is why I'm here. If I knew someone who could lend a hand, I wouldn't be posting... Anyway, I'm here to learn. About the marque, the history, as well as the care and feeding of. Mostly the latter as of late. It finally occurred to me that syncing and idle mix tuning are two separate things, although interrelated. Yesterday I synced the carbs, following the instructions in the service manual, which are probably one of the clearer explanations I've found. I also tried to adjust the idle mixture using the Colortune, but all it did was make things worse. To sum up, for the sync (all in the service manual): * the linkage is attached, centred loosely, and tightened to carb no 2 (second from the firewall). * all air bypass screws are snugged down, locking nuts loose * Idle mix screws are seated, then turned out 1.5 turns * Carb no 2s idle speed/throttle stop screw is turned 1 turn in from contact. The remaining carbs have their throttle stop screws backed off. * Air pump hoses are disconnected and plugged, microswitch is disconnected (there is a molex right there that can be unplugged). * Start and warm up the car. My car needed someone to babysit the throttle for 5 minutes or more before it would idle on it's own, but it's freezing here. When it finally settled in, it idled on it's own. The manual recommends both water and oil to be > 50C. * Use a syncrometer to measure airflow between barrels on each carb, if there's an imbalance open the air bypass screw on the barrel flowing the least air to match the higher flowing barrel. I found revving the engine and trying different rpms helped arrive at a good all around setting, as it seems to vary slightly. * Use the linkage nuts to adjust the airflow between carbs, using carb no 2 as a reference (since it's fixed to the linkage and it's throttle stop screw serves as 'master' setting for overall idle speed). I had greased the linkage and was able to do this by hand - minute changes make a big difference in airflow. I have to go back and actually tighten everything down as there's still enough slack that things move in between starts, or when applying the throttle. That's basically that for syncing the carbs. The goal being that all carbs flow the same amount of air into the cylinders. I'm not sure how precise one needs to be, I noticed mine tended to drift with time and between starts. Maybe because I hadn't tightened it down. I was able to achieve a pretty smooth and even idle. 1.5 turns out on the idle speed screw was not enough gas in the mix and the engine would stall after turning over. After adding 1/4 turn more all around she fired right up and idled fine at about 900 rpms. The nice thing about this way of doing it is that *1* screw adjusts the idle speed and airflow for *all* carbs. So if you need to increase/decrease the idle, the throttle stop screw on carb no 2 is the master that controls all the rest. Very simple and effective. So I proceeded to try out the Colortune, and that's where things became problematic. I know several people here use and recommend them. I'm either doing something grossly wrong, or there's something wrong with my car, or I don't know what. Installing the Colortune and running the engine shows spark, but no flame. This was across all cylinders but one, which had a yellowish flame that I tuned to bluish white by dialling down the idle mixture screw. So according to the Colortune, my car shouldn't even be idling, as there's no combustion taking place! I fiddled with the idle mixture screws to see what I could discover, and was able to get a yellow flame, but when dialled down to blue-white it wasn't consistently firing on each cycle. Nor was I able to discern an increase/decrease in idle speed when adjusting the idle mixture screws. Maybe it's harder on an 8 cylinder motor with each cylinder only contributing a small amount of the total energy? The "bunson blue" they recommend never appeared in my engine, I could choose between yellow, yellow with hints of blue, or blue-white, ending up somewhere between the latter two. After adjusting as best I could with the Colortune, the engine idled worse than when I started. :-/. I think I need to find a dyno shop to take a look at it with an exhaust analyser and take a more scientific approach. In the meantime I plan on putting all idle mix screws back where they were (1.75 turns out from seated) as the engine was reasonably stable and smooth at that setting. If anyone has any tips or advice as far as setting the proper idle mixture goes, please let me know!
The hose in pic #5. You can tell if it's a vacuum hose by plugging it to see if it makes a difference. Where does that connect to on that end? Where does the tee and other two legs go? The hose in pic #4. I honestly have no idea can you smell any coolant in the end? There can be thermostat bleed hose in that general vicinity as well. You need to trace down all of these hoses, their purpose and where they should be plugged. If you're is a car with emissions stuff on it(looks like it to me) then these hoses may be related to that system and there should me a metal plate in the engine compartment that serves as a schematic. I believe these cars had a silly little evacuation pump that sucked gas fumes from the air cleaner box after shutdown and blew them into one of the carbon canisters. Upon startup the canisters get purged by sucking some air through them which goes into the air clear assembly so maybe that's one of those hoses. The diagrams of these connections is somewhere so find that and identify everything. Check Enrico's Maserati website for a manual if you don't have the big silver book. One hose does go from the intake manifold over to the distributor as a part of that advance/retard system operated via the micro switch on one of the carb throttle shafts. It seems to me like that's where you might have a potential vacuum leak but you also need to check the entire brake booster circuit. Plenty of stuff to learn about and run down so get the proper documentation and get to know that engine compartment intimately.
It makes a difference if the engine is cold. The hose is connected to the front and rear of the manifold with a tee to the "consumption" gauge at the rear, and a tee to the air cleaner baseplate at the front. The same opening on the baseplate connects to a breather hose on the valve cover. Basically a loop connected to the gauge in the car. It's a breather hose from the heads, off the valve cover to the air cleaner. No coolant ;-) I've disconnected and plugged the air pump hoses as per the manual, and disabled the microswitch. The setup looks like the mid 70's "A.I.R." system, a pump forces fresh air into the exhaust as it leaves the cylinders to combust unburned fuel leaving the cylinder, and charcoal canisters collect fuel vapor from the air box. I've not disconnected the hose from the distributor, nor does the manual indicate to do so. Although from what Tony posted, it may be connected somehow to the microswitch. The hose connected to my distributor is (from memory) connected to the small valves/solenoids mounted on the driver's side closest to the firewall (see pic). I'm not sure how all the smog stuff works, and to be honest was hoping to remove it all at some point. For now I need to get the car running enough that I can move it from the workshop where I've rented a spot back to it's parking space. Then I can keep tweaking and adjusting things on my own. I have the service manual, if that's what you mean by the big silver book. There's a diagram on the inner fender of the car, but it isn't especially clear to me. Then again, I'm not a mechanic or engineer. That's what I'm working on, Bob. When things aren't clear in the documentation, it helps to ask ;-) So the carbs are balanced and linkage locked down. All flowing the same rate of air. It seems to idle fine now. Any advice on setting the idle mixture? Colortune didn't really help. Image Unavailable, Please Login
I wish I could help you but my car only has the air pump system that puts air into the exhaust headers and even that has been disconnected. I can assure you that the microswitch system applies vacuum to the distributor while idling because I've tested this. Maybe, now that you've got the balancing locked down, put everything back together (velocity stacks, all hoses and air box) and see if the colortune works as expected. I know it'll be very difficult to get to the fuel mixture screws but you might be able to manage. At least you can drive it home. Good luck! t
Had another go at the carb syncing today. The car fired right up on the first try and idles pretty good even when cold. I was pleasantly surprised. Airflow was uneven, but got closer as the engine warmed up. Did some more tweaking and locked down the linkage as best I could. Took a 15 minute break, started her up again and found a few more imbalances that I adjusted away as I was able. It seems to drift and I'm not sure how obsessive one needs to be with it. Found a few gas leaks, fuel inlet washers and fuel filter washers, snugged them down. Maybe because of the cold weather lately. Two accel pump nozzles were dripping, I made sure all the accel pump covers were tight and the leaking stopped. Made sure the cover screws were tight too. Colortune didn't work as I had expected, it looks a whole lot simpler in the videos. I plan on experimenting with the idle mixture screws this weekend and try out a few methods I've read about. One is to use airflow and adjust for fastest rpm & highest airflow, using the syncrometer. Another is to start at 1.5 or 2 turns out, screw in until the cylinder dies, then out until rpms no longer increase or it runs worse, then 1/4 to 1/2 turn in. Since it seems to be idling fine as is, I'm going to log the current settings before I change anything. If anyone would like to share their tuning story, please do Sent from my iPhone using Tapatalk
my QP 3 will b home next week end. unless another surprise. also coming home will b two 400ai's that still leaves a 2002 cc spyder at the Cleveland dealer sorting out the mouse chewed wiring! getting expensive. and the 365 in Alliston ca. maybe by spring. 60 days, maybe
Two accel pump nozzles were dripping, I made sure all the accel pump covers were tight and the leaking stopped. Hi Again, Sounds like you still might have either too high a fuel pressure or leaking needle valves. Have you tried tweaking the pressure down using the regulator? Maybe this is why colortune is still hard to read if excess fuel is dripping down intermittently? Both ways of adjusting idle mixture should be OK but the synchrometer is not fantastic at giving you a great read on whether the revs are higher or lower- it doesn't seem accurate enough unless you have make big changes on the screws Julian
So you've ascertained that there are no slight or major vacuum leaks now? I've mentioned this at least once, don't obsess over the flow and do wait for the warm up. There are a not of metal pieces interconnected that expand with heat. Tune it for the weather you're most likely to drive it in. A single throttle plate is always so much easier. The carb in my Biturbo never needs adjustment, is incredibly reliable which is a good thing since it's sealed in a very hard to get ato box. Tuning that car with different jetting was a real PITA. Once the car is nicely warmed up and idling well turn the other three throttle stop screws so they are just touching and if it increase the idle speed back it off until it just backs down. Do this dead last after everything else is settled. You may have to go through a couple of iterations of this entire process before you can settle on "it's good enough" but try to do each time under the same conditions otherwise you're just chasing your tail. The idle circuits contribute a lot to how the engine runs at higher rpms and throttle positions so go out and drive the car to see how it responds as well, it's not just about idle performance. If your kets are too lean you will get flat spots and transitions issues. On my Espada I hjad to change the size of the original factory spec jetting to compensate for the 10% alcohol gas. I could not make it run right with the stock jets. I could get a decent idle but the driving at speed was terrible. Get yourself a digital tach you attach to the coil so you can watch the rpms. Then you can enrich and lean out the idle settings to see the effect it has. Once you get a reasonable result I would log the amount of turn in either direction you make rather than the number of turns all the way from zero. Be gentle. Never turn the idle mixture screws in all the way very hard as you can punch a hole doing that. Same for those cross balance adjustments. Don't over snug any screws either you can warp stuff or worse doing that. With the the digital tach, your ears, some test drives and practice you'll get the feel of it. I'll be curious to see how the color tune thing works out. You're on your way.
Hi Julian, the needle valves are new, float height set and double and triple checked. All ok. As far as the pressure goes, I can't check it as my gauge died. Am ordering new one, but it will be another week before I get it, at the earliest (such is life living at the edge of the known universe). That said, the regulator was new a year and a half ago, and was set and locked at 2.5psi. I wouldn't expect it to die that quickly, but you can never be sure. I did find that a few screws on the accel pump diaphragm covers were loose on the carbs that were dripping from the accel nozzles. Probably that let air in and caused the nozzles to drip. I went over all of them and snugged everything down a little bit extra - I don't want to damage the aluminum, but don't want them coming loose either. The Colortune sucked equally on all cylinders, I'm a bit disappointed that it didn't work as clearly as in the videos. So I don't think it was only due to a leaking nozzle. At this point I need to vacate the workshop soon, so will dial it in by ear for smoothest idle, staying close to the existing values, and book a session with the dyno shop for final fettling. It's going to be exciting finally taking the car out for a drive to see how she runs!
Indeed I am (on my way). None that I can find. Have sprayed carb cleaner around each baseplate, body, hose joints and hoses themselves without noticing any change whatsoever. Disconnected the air pump and plugged the hoses as per the manual. Will do, thanks for the tip. Right. They add alcohol to the gas, but I don't buy the 10% stuff, still running the old fashioned blend. I'm not sure of the exact percentage, but I think it's closer to 2-3%. While it lasts, that is... Me too. So far it was nothing like the videos on YouTube - those make it seem dead simple. I get spark but no flame unless I increase revs. Same across all cylinders, which leads me to suspect a timing issue. Although I paid a mechanic to go through and adjust the timing, cams, check for vacuum leaks, and a host of other things. I don't really take anything for granted until I can verify it myself. Or perhaps the timing is changed when all the vacuum stuff is connected, and the Colortune will show a different result when everything's attached. I suppose that doesn't make any sense as both it and the manual specifically state tuning should be done with all smog & vacuum gear disconnected. At 900 rpms each cylinder should fire 450 times/minute, 7.5 times every second. That should give a pretty steady flame showing the combustion as it happens. I get a flame every second or two, maybe. Revving the engine up results in a constant flame of correct color (bluish white). I'm going to keep fiddling with it and fine tune it as you suggest, and perhaps maybe even learn a thing or two along the way ;-)
Congrats Mitchell! I'm curious to hear your impressions when you finally get to drive your QP3. Especially compared to something like the 400i, which seems to be the contemporary competitor.
The vacuum retard will most certainly change the idle by reducing it and it also makes it smoother but then you get that just off idle jump when you step on the gass as the micro switch disconnects the vacuum source. At least that''s how it works on my Bora which is why I left it off permanently. There's an actual small plastic vacuum cannister just for that purpose. Now when you disconnected the vacuum gear you did plug the vacuum side of those hoses right?
What? What does the synchrometer have to do with setting idle mixtures? Did you inadvertently mix two different topics in one sentence there? I've never have a problem moving it from one carb to another quickly when balancing air flow. It's a lot more challenging on an old Lambo V12 too!
"One is to use airflow and adjust for fastest rpm & highest airflow, using the syncrometer" If you are after the fastest idle you could use the synchrometer to see if you are achieving a faster idle. Basically faster idle equals more airflow. But its a blunt tool. Its not accurate enough and you need a digital tachometer to pick up subtle gains / losses in idle speed as you suggest. Don't ask me how I know, I just do!!!
Indeed I did. Good for me ;-) I may just leave my micro switch disconnected as well. It seems to run ok without it. Will have to do some testing and see. Julian was commenting on one method of setting idle mixture adjustment I had heard about, that involves using a syncrometer to adjust for highest airflow, implying highest rpms. He said it wasn't really much help as far as that goes, but obviously is a great help in balancing airflow overall at idle.
