johnj92131 Posted March 1, 2017 Share Posted March 1, 2017 Can anyone point me to a reasonable price Air/Fuel meter? Looking for something to put in the tail pipe and help me adjust a multiple carb system on an older car. Thanks, Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 2, 2017 Share Posted March 2, 2017 I have a Cyberdyne in my car. It is basic as they come. Link to comment Share on other sites More sharing options...
fiatslug87 Posted March 3, 2017 Share Posted March 3, 2017 I have a Cyberdyne in my car. It is basic as they come. Didn't they also create Skynet? http://terminator.wikia.com/wiki/Cyberdyne_Systems :rotf: Link to comment Share on other sites More sharing options...
johnj92131 Posted March 3, 2017 Author Share Posted March 3, 2017 This is what I found when I chased down Bo's Cyberdyne: http://www.cyberdynegauges.net/air_fuel_gauges.php I am actually looking for a test instrument with a tail pipe probe so I would not have to weld in a wide band sensor bung into the exhaust system. But it may turn out that a weld in bung might be the least expensive way to go. Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 3, 2017 Share Posted March 3, 2017 My gauge taps into my o2 sensor wires. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 3, 2017 Share Posted March 3, 2017 My gauge taps into my o2 sensor wires. Narrow band A/F gauge? Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 3, 2017 Share Posted March 3, 2017 It is. It does just enough to tell me when to get out of it. Boost and A/F is a scary game. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 3, 2017 Share Posted March 3, 2017 If you know how to read the narrow bands the info they provide is as good as the wide band meters. Link to comment Share on other sites More sharing options...
johnj92131 Posted March 3, 2017 Author Share Posted March 3, 2017 I am looking for something to help me tune the 4 carburator setup on my Corvair. I have one primary and one secondary on each cylinder bank. All 4 carbs have an idle circuit and the idle seems to be OK. But when I put my foot in it, it bogs down. One bank seems to be running way too rich. So I think I need a wide band O2 sensor. Bo - are you not running an Exhaust Gas Temperature gauge on your diesel? That will tell you real quick when to back off the boost. I had my tuner cut way back on the fuel at high boost levels to keep from melting a piston or blowing the turbo on my Passat diesel after I put a bigger turbo on the Passat. Link to comment Share on other sites More sharing options...
Jeepman Posted March 3, 2017 Share Posted March 3, 2017 I am looking for something to help me tune the 4 carburator setup on my Corvair. I have one primary and one secondary on each cylinder bank. All 4 carbs have an idle circuit and the idle seems to be OK. But when I put my foot in it, it bogs down. One bank seems to be running way too rich. So I think I need a wide band O2 sensor. Bo - are you not running an Exhaust Gas Temperature gauge on your diesel? That will tell you real quick when to back off the boost. I had my tuner cut way back on the fuel at high boost levels to keep from melting a piston or blowing the turbo on my Passat diesel after I put a bigger turbo on the Passat. I do just this using a Standard dash mount A/F guage and I bought a cheap one from Glowshift and the cables are long enough to plug everything in and slide the 02 into the tailpipe which works great for tuning carbs especially 4.2L computer controller carbs... http://www.glowshiftdirect.com/ This is the one I bought a few years back http://www.glowshiftdirect.com/Elite-Series-Wideband-Air-Fuel-Gauge.aspx I run an autometer A/F in my MJ but thisis perfect for tuning... Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 4, 2017 Share Posted March 4, 2017 The Cyberdyne is in my Shelby. I have the Glowshift EGT in my Cummins though. Link to comment Share on other sites More sharing options...
johnj92131 Posted March 4, 2017 Author Share Posted March 4, 2017 Bo, Did you add the GlowShift to your new truck or was it there when you got the truck? I am going to add an EGT gauge to the diesel Comanche and GlowShift looks reasonably priced. Also plan on calling GlowShift to see about their air/fuel gauge next week. Thanks to all for the pointers!! Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 I am looking for something to help me tune the 4 carburator setup on my Corvair. I have one primary and one secondary on each cylinder bank. All 4 carbs have an idle circuit and the idle seems to be OK. But when I put my foot in it, it bogs down. One bank seems to be running way too rich. So I think I need a wide band O2 sensor. Bo - are you not running an Exhaust Gas Temperature gauge on your diesel? That will tell you real quick when to back off the boost. I had my tuner cut way back on the fuel at high boost levels to keep from melting a piston or blowing the turbo on my Passat diesel after I put a bigger turbo on the Passat. Sounds to me that you need a UniSyn . Gotta make sure all 4 carbs are in sync both at idle and a bit above. I've never needed anything more to tune multiple carbs. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 5, 2017 Share Posted March 5, 2017 ^^^ This. Must have tool. Just for grins cut off a hunk of 1/2" or so vacuum hose, stick one end in your ear, then the other end into the carb intakes one by one while idling. Guarantee you will hear each of them sucking at a different pitch. You can get them pretty close by adjusting the idle needles on each. Then observe the butterfly opening on each carb when opening the throttle linkage to the stop. Adjust the linkage so each carb butterfly opens the same amount. You can fab a feeler gauge to do this. That will get you in the ballpark. :cheers: The vacuum hose works great on Brit and Swedish cars with side draft SU's and Webers, but I've never tried it with the Corvair Rochester carbs. Link to comment Share on other sites More sharing options...
johnj92131 Posted March 5, 2017 Author Share Posted March 5, 2017 I am looking for something to help me tune the 4 carburator setup on my Corvair. I have one primary and one secondary on each cylinder bank. All 4 carbs have an idle circuit and the idle seems to be OK. But when I put my foot in it, it bogs down. One bank seems to be running way too rich. So I think I need a wide band O2 sensor. Bo - are you not running an Exhaust Gas Temperature gauge on your diesel? That will tell you real quick when to back off the boost. I had my tuner cut way back on the fuel at high boost levels to keep from melting a piston or blowing the turbo on my Passat diesel after I put a bigger turbo on the Passat. Sounds to me that you need a UniSyn . Gotta make sure all 4 carbs are in sync both at idle and a bit above. I've never needed anything more to tune multiple carbs. Hi Cruiser, I have had a UniSyn since the late 1960's. Used it first to set up the dual carbs on my 63 Sunbeam Alpine in 1967/68. Later used it for all the Corvair multiple carbs I had. The UniSyn is a great tool. Don, My hearing is a problem for using the hose as a tuning tool. The hose used to work very well on the Corvair Rochester carbs. Add the UniSyn, then properly adjust the linkage as you say. End result was a very smooth running engine with either 2 carbs or 4 carbs. Guess I am trying to at least move into the early 1990's with an O2 sensor! Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 You can adjust the idle mistures but the main and acceleration circuits should only be affected by float level. After that, the Unisyn is the best tool. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 5, 2017 Share Posted March 5, 2017 The throttle valve regulates air velocity through the carb and controls the amount of fuel delivered to the engine. If in a multiple carb setup the throttle valves don't open equally it will affect the main and acceleration circuits as much if not more than float level. Float level is set and forget as long as it doesn't clog up. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 The throttle valve regulates air velocity through the carb and controls the amount of fuel delivered to the engine. If in a multiple carb setup the throttle valves don't open equally it will affect the main and acceleration circuits as much if not more than float level. Float level is set and forget as long as it doesn't clog up. You obviously never worked on SUs and Webers. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 5, 2017 Share Posted March 5, 2017 Was referring to the Rochester Corvair carbs as in the original post. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 Even so, Rochesters are not exempt from sunken/saturated floats, bad needle and seats. Best to set a good baseline. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 5, 2017 Share Posted March 5, 2017 Okay Grandma. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 Grandma's multiple carbed vehicles always ran great when float levels were verified and then synchronized with a UniSyn. Many times float levels were found to be off...... Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 5, 2017 Share Posted March 5, 2017 :smart: :ack: Link to comment Share on other sites More sharing options...
johnj92131 Posted March 5, 2017 Author Share Posted March 5, 2017 The Corvair has a real, original 25,000 miles on it! Carbs don't look like they have ever been taken off or opened up. Original floats were metal, but with current crap for gas, who knows what kind of shape the floats, etc are in. Also, want to put off opening the carbs if possible for as long as possible. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2017 Share Posted March 5, 2017 If it only has 25,000 miles on it, I would be more likely to think of rubber tips on needle and seats being disintegrated or clogged air passages than the carb linkage being out of adjustment. Link to comment Share on other sites More sharing options...
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