How to make the BASE setting for the A/F Screw??
 

I just finished putting in a New Airbox and have sealed ALL of my Air Leaks. The Problem now is my setting of this Screw is Totally Off. I have turned it left for lean and right for rich several turns both ways and cannot get it close enough to run! I got the car to almost run (the intermittent firings with the Starter turning it over) but it will not run contuniously.

I do have Spark and I put in a relay that makes the fuel pump run all of the time to bleed the system. Once done I removed it and put in the standard relay and need to get to a base setting for the A/F to get started so I can make the adjustments once it is running.

Anyone got any ideas or dealt with this before??

The trouble is, there doesn't seem to be any real calibration to the screw itself per se. You have to make sure your control pressures are correct first, and do the other things you mentioned, incl getting spark, having correct timing, and eliminating vac leaks. Then a check w/ an A/F meter is best to set the mixture.

Since I don't have an O2 sensor and system I am not too familiar w/ using a dwell meter to set what is called the "duty cycle", except to tell you that that is another technique . This can be done only w/ a Lambda system engine. If you search "duty cycle setting" or something like that you should find the procedure.

If you don't have O2, an A/F meter or a dwell meter, you have to use a trial and error to get the engine to start and run. I've had my car for over 20 years, so I can identify a rich or lean condition. Some typical rich condition symptoms include a hunting idle, blackened tailpipe, and a drop in revs when coasting to a stop. A lean engine can yield a light tailpipe color, overheating, a too-freely revving engine, and bogging from a start.

If you go too rich, at least you may be able to get the car to a shop where the O2 can be set, w/o harming your engine.

Thanks Paul. As good as the Bentley Service Manual is, They TOTALLY Miss it on this problem! You have to be able to get the car running BEFORE you use an Analyzer!

The Good new is, I have 2 other Service Manuals a CLYMER & HAYNES! The Clymer has a lot on Carburators and the HAYNES a lot on CIS.

THE HAYNES HAD THE ANSWER

Turn the screw several turns counter clock wise. Then turn on the Ignition with the Fuel pump relay made to run the Fuel Pump full time. (By accident I messed up a relay that now does this!)

Second, Pull an Injector and continue to turn it until the screw counter clockwise until the fuel stops.

Third, Turn the screw Clockwise until the fuel just starts to dribble.

Last, turn the screw 1/2 turn Counter Clockwise back and you are set!

Now at least I can get started and then tune it to start and run right.

"Well it Worked!! In the Rain, I just went out and turned on the Fuel Pump and pulled out 1 injector then turned in the A/F Screw on the CIS Counter Clockwise until it stopped leaking. I then turned it Clockwise until it started leaking and then Back 1/2 turn.

I Changed the Relay back to the Normal one and turned over the engine after a shot of Starting fluid in the Pop Valve. The engine started to run on the starter and a lot of smoke came out of the exhaust. Slowly the exhaust cleared and the engine was running without the starter. (Flooded badly). After a few adjustments on the 3 mm Allen wrench it was running GREAT!

It took a lot of turns on the Idle screw to bring the Idle up. Before the AirBox change the screw all of the way in had a 1100 RPM Idle!