Just barely failed emissions(dammit)

[88-383]

My HC's moved just outside passing when the truck shifted gears and went into 3rd during the loaded dyno emission test at 25mph. I'm wondering whats the easiest way to get a pass? Should I try and lean it a little more in 3rd w/light load? Play with timming? Fuel pressure?

Thanks

Kelvin

http://www.jaybquick.com/_Kelvin_Upload/Smog Test-1.tif

Setup:355,10.1,CNC TF 195's,Ported Edelbrock manifold,46mmT-body,75#inj's,[email protected] .520 HR etc....

 

[1979jimmy350]

you could pull a little timing and maby a little fuel

 

[88-383]

Yup, I think another chip will have to be burnt

KM

 

[Creek]

You might want to look at the Accel. Enrichment Vs. Differential MAP table. Also be aware that once the mixture gets too lean it can cause hydrocarbons to be high because the flame front can't sustain its self across the chamber. This is more predominate during high cylinder pressures (higher MAP) such as occurs when the RPM drops under load. Also look at your knock counts at that time as detonation can cause an incomplete burn.

 

[4X4HIGH]

A new cat will cure it.

 

[88-383]

I wish, it has a brand new factory cat with about 30mi on it. I'll post back after I get it sorted out.

km

 

[4X4HIGH]

Well, was the vehicle nice and hot when you had them smog it, if not that will make a difference.

 

[MrArmyAnt]

Or jam it in 4wd, here in texas they usually dont dyno 4wd, just neutral and smog test... If that.