whoa take it easy....

The engine was cold and yes at 400 rpms I'm getting 7.5 InHg
A/F at idle will wander between 13.5 and 16 at idle with avg readings in the upper 14s to mid 15s. Im thinking that 16.8 was probably a result of the engine being revved up for a sec then spinning back down it does not sit at 16.8 for the entire time...look how killer it was in the other 2 pics For whatever reason A/F readings have a larger range at low speeds including idle but above 60 they tighten up and at 80 im pulling between 14.2 and 14.6 consistent

Vac is 15 inhg under load at about 45 mph with A/F between 13.6 and 14.9 avg about 14ish

-Gun

 

now that explains it. once i get back to ireland I'll try as well to get my carb into 13.5 to 14 direction on WOT. just ran out of time.

just out of curiosity. when you drive slightly uphill at 50mph with a bit of an accelleration (not WOT). what vacuum would you read ?
i'm trying to compare this to idle vacuum to get an idea of what relations are there

 

Gun Jam, 14.9 is stoichiometrically lean, as well as lean for a carb. I'd try to richen it up a bit. Do you have any hesitation issues as you move to part-throttle?

 

No I don't have any hesitation issues...For example im going 45 mph and lets say A/F indicated 14.9 for that given instant in time. If I apply power say from cruise to WOT during that given instant in time I don't feel any lag in power and A/F reading will be around 12 at the same time the pedal reaches the floor. Again the A/F reading wanders abit so my goal was to tune the carb so avg readings were on target and no extreme lean/rich readings were present during power or transfer from cruise to power.

If anything it maybe a bit lean at idle...ill adj it next time I fire it up

-Gun

 

What does stoichiometrically lean mean? I've never heard that word.

 

I like that A.F. meter. Where'd you get that and how is it hooked up? Where does it get it's reading?

 

-Step

Thats a PLX-500 It has 2 parts, a small box that gives a reading and also sends that reading to the gauge. The Box also sends a wireless signal that can be used to create a graph on laptop run software.

The wide band A/F sensor is made by Bosh

here is a thread about it with nice photos...

https://mustangforums.com/forum/clas...io-instal.html

These units sell for over 400 iirc....however I can get you one for 275 if your interested it would come with everything except the round gauge...I think those are another 75 or so direct from PLX

-Gun

 

-6t5

stoichiometric is a measure of chemicals / products produced during a reaction....about 14.6 A/F gives a burn rate that allows for complete reaction of the burn with no un-reacted elements left. If its above or below 14.6 reaction is not 100%

-Gun

 

In theory (although it's closer to 14.7:1). In practice, you're not getting 100% burn in a gasoline engine, ever. In addition, carbed engines often like to run closer to 13.2:1 for best power and throttle response. 12:1 is a bit rich, but to be expected during throttle plate opening as the accelerator pump dumps fuel down the intake.

But hey, if it works it works

 

That is exactly why cars have catyletic converters.