Just to follow up I have been running numerous tests with an LM-1.

I currently have my CO set at roughly 3%. While driving the car I watched my mixture numbers and liked what I saw. Nice enrichment on WOT.

One question remains though, at 2300-3000 RPMs I see my leanest condition at14.7 AFR.

Is that too lean or is it still ok?

I'd say that's ideal for fuel economy and emissions.

A/F at WOT is open loop. That is, sensor input is ignored in this mode and the default is what is allowed by the ECU.

Sherwood

Been folling this thread closely... What if you have no ecu?? like my ROW? All I have is the mixture screw...

Comments Sherwood?

-Michael

Craig,

14.7 is stoich so your LM-1 would show it as "joosta right" for economy and emissions. More importantly, I think, is that stumbling you were getting. Has it disappeared w/ this setting?

Michael,

W/o an ECU you are relying on your mixture screw setting and the design of the CIS system to give you the best setup under all conditions. If you have an A/F meter you should find an idle setting of about 3.5% will give you best performance according to JW. I've always set mine by feel. I've found that if @ warm idle I get good pull up to redline and then the idle speed does not drop down before returning to the correct point, or if @ idle there is no hunting, then it's good. A recent test w/ an LM-1 confirmed this point is 3.5%.

For some reason I was thinking that 14.1 was stoich. Good to know that I am ok at 14.7.

Still have stumble. My troubleshooting was on pause this weekend since I had to do my final valve adjust. This was my first solo valve adjust - between changing the oil, sump plate, checking my cam timing, and putting my muffler back on it took me all weekend to complete. Not as fast as others b/c I am a noob.

Next step is to swap coil then dizzy. Again, I am not too bothered by it. Just want to make sure that I am not running too lean where I would be damaging the engine.

Four of us in the area are going to split the cost of an LM-2. I have been borrowing the LM-1 and it sure is a nice piece of equipment to have on hand.

It is easier. You can play with the idle adjust screw and fuel mixture screw. I have an LM-1 but with RPM sensor and it tells me I am fine at idle anywhere at between 14 and 14.7 I tbelieve that that gives you 3% and not 3,5% co but maybe it has something to do with altitude. I have seen numbers on this site that I can not match from people in Denver and that is pretty high up.

Stupid thing is you do not really need the LM-1 on a RoW SC. If the idle hunts at warm-up you are to rich if it stalls at warmup you are to lean. If you are in between and your warm-up is smooth then believe it or not the LM 1 shows 14.x. I would say the differen is about 1/2 a turn on the mixture. Ofcourse this is when cold start valve , AAV, Thermo time valve all work well.

I am at sea level. Car is a 1983 SC RoW no Ecu no 02, no mods.

AT 6000Rpm you want to have 12.7 or somewhere around that. I run 98 Octane.

One thing that made me go around the block several times was the decel valve. I could not get my idle stabilized even though all my numbers where spot on; until I swapped the decelvalve and the tubing. Turned out the decel valve membrane had a hole in it and let air through once every so now and then ;o)

Also one for the books I believe your timing needs to be excellent before setting the mixture. I was trying to do mixture with timing fairly far off and I did not get good results. Now this could just be me being stupid.

Michel