Big NO Problem

[broke it]

Hi,
This is my first post so I'll try to keep it brief. Sure.
Virginia has local, private service center Emissions testing. Although Va. prefers the 2 speed roller test, it does allow a 2 speed idle test if the local tester deems it appropriate. The roller test checks HC, CO & NO. The idle test checks only HC & CO. My local tech has always done the idle test as the car shifts really hard and wants to "jump" on the rollers. This last time we both forgot and did the roller test. As the Champion heads EGR passages are filled, the car failed the NO portion of the test miserably.
Heres my questions:
1. Are there any tuning tricks I can do in terms of Emissions chips, fuel pressure, etc, to try to get the car to pass on NO? The car does have an ATR cat. thats about 9 years old. According to the folk at ATR it should be a 3-way, but maybe its just worn out. No problem getting a new one if it might help.
2. Does anyone know how long failed emissions tests stay in the VA system. VA does allow a free retest within 2 weeks of the failed one, but if the info has since been purged, my tech could redo the test as a 2-speed idle test, hopefully passing with flying colors.
The failed test was back at the end of October. One day before the Tags died. Since then I've been warming the car up in the driveway at least once a week and occasionally sneaking the car out early Sunday mornings around the neighborhood just to keep everything up to snuff.
Heres the test results:
HC ppm: Limit 118, Me 29
CO: Limit 0.66, Me 0.00
NO ppm: Limit 905, Me 2312
15MPH

HCppm: Limit 114, Me 46
CO: Limit 0.70, Me 0.00
NO ppm: Limit 824, Me 2241
25mph

Sorry this post got so long. I don't do this very much..
Thanks for your time and hope to hear some advice soon. I miss my Baby very much!

Joe

 

[gofstbuick]

How many mile on that cat? It may be done. have your buddy get the car up on the dyno and run it for 3 minutes. Or do a freeway run (after the engine is fully warmed) for at least 3 minutes. Then do a temp test at the entrance flange and exit flange. The exit flange should be at least 100 degrees or more than the entrance flange. The oxidation in the cat creates heat due to the energy spent to change HC and CO to CO2 and H2O, so the temp behind the cat will be hotter. Since the CO is zero, try increasing fuel pressure. Since the vehicle wants to jump the dyne, are the restraints in position? and are the front wheels chocked? if not they should be. Snap-On sells a wheel chock that clamps in front and behind the non-drive wheel. Because the vehicle is stationery, there is really no inertia to move the vehicle very far, but may move it far enough to pull the tach lead and/or the gas bench against your vehicle. So if the wheels are chocked, they should be!!!!!!!!!!

 

[broke it]

Hi,

Thanks for the reply.

The milage on the cat is nil. Only on for about a week before any given test, off within a week of any test. Is very sooty inside, but when sighting down it, the matrix is intact; has that typical 'lensing' effect. The cat has been subject to a few problems though. Several bad plugs, wires and at least one bad coil. Definately has been run way too rich a few times. Reactants inside may well be shot. Probably will go ahead and get a new one.

I have access to a Fluke infrared thermometer at work and can probably bring it home to do the temp in/ temp out cat test if thats the kind of thermometer your talking about. May take a while though; am sneaking the car around the neighborhood with dead tags!

Please don't misunderstand my comment about the car 'jumping' on the rollers. That is only our justification for doing the two speed idle test (w/ out the NO test) as opposed to the roller test(with the NO test). Not truely a problem. This time we just forgot and did the roller test. Had we remembered, this situation would never have come about in the first place.

Again, thanks for the reply. I'll let you know the cat temp test results.

One last thing. What would be a good line off fuel pressure to shoot for?

Joe

 

[gofstbuick]

Originally posted by broke it

One last thing. What would be a good line off fuel pressure to shoot for?

Joe

What is the FP currently set at? Try 2psi higher that where it's set at now