Griffith 4.0 Carbon Monoxide level

[TVRJones]

Hi, I'm struggling to find the what the correct CO level is for a 92 4.0 Griffith? Could someone point me in the right direction?

[blitzracing]

I assume its pre cat so the margins are pretty wide. If you are trying to set the mixture with the CO trim at idle its quite difficult due to the lag between setting the trim and the results in the tail pipe, so personally Id prefer to set it by ear. You wind the CO trim anticlockwise until the idle becomes rough (This is on a Lucas Hitach 3AM AFM) when its to lean, then wind it clockwise until the idle is smooth. You can keep winding, but the CO just keeps going up with nothing to be gained. Ill check the actual factory value when I get home later.

[TVRJones]

Thanks Blitz, so no need for a meter then by the sounds of it? Just make it run lean the ease it back?

[blitzracing]

It should officially be between .5 and 1% for the non cat. The RPI has this bit about setting it by voltage on the AFM, (towards the bottom of the page) which is fine as a place to start, although I still reckon by ear is a good bet. Ive tried with a CO meter and ended up with 2.5% to get a smooth tickover on one car.

http://www.v8engines.com/carbs-2.htm

[TVRJones]

blitzracing said:

It should officially be between .5 and 1% for the non cat. The RPI has this bit about setting it by voltage on the AFM, (towards the bottom of the page) which is fine as a place to start, although I still reckon by ear is a good bet. Ive tried with a CO meter and ended up with 2.5% to get a smooth tickover on one car.

http://www.v8engines.com/carbs-2.htm

Thanks for the information, the RPI site is great - thanks for pointing me to it. I'll follow the by ear method I think as you suggest.