Jump to content

Air/Fuel Meter


johnj92131
 Share

Recommended Posts

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

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

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

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

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

^^^  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

 

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

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

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

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...