failed emissions this morning.

[one92rs]

got the plugs changed. put in autolite 26. both places were out of the r45ts. new cap and rotor. not I do have a question.

on the egr solenoid. on the two vacuum ports. one has an orfice and the other does not. does the egr valve hook to the orfice port or open port. I had mine from the tbi to the orficed port and the open port to the egr.

and evidently I have forgotten how to log with tunerpro. guess its been a long while. need to find that tutorial again and read it.

and today I was given a 1227747 ecm out of a 1992 chevy 1500 with a 350. are the 7747 any better than the 8746 ecm's?

[one92rs]

will log tomorrow. I think I got it. had to go back in and set it to find the cable.

[EagleMark]

I'd have waited for the right plugs. Not sure about the EGR? Your 8476 is just as good as 7747 plus has an IAT.

Do you have an Air Pump?

[one92rs]

No air pump

[Fast355]

The last time my 1983 G20 had to pass emissions in DFW it was a TBI injected, vortec head 8.9:1 350 with long tubes and no cats. Running without EGR and tuned with the EBL. On the loaded emissions dyno it ran cleaner than a 2006 ULEV Honda Civic that had the then new CAN databus that would not communicate with the state machine and had to be run on the dyno.

Low Speed Test (15 mph)

HC.... Standard...332 ppm....Reading.....50 ppm
CO.....Standard....1.89%.....Reading.....0.10%
CO2....Reading 14.5%
02......Reading 0.0%
NOX...Standard...2490 ppm...Reading....72 ppm

High Speed Test (25 mph)

HC.... Standard...326 ppm....Reading.....42 ppm
CO.....Standard....2.62%.....Reading.....0.03%
CO2....Reading 14.5%
02......Reading 0.0%
NOX...Standard...2320 ppm...Reading....47 ppm

The secret.....Disconnected timing connector and massively retarded ignition timing although you could burn a .BIN that had the timing map level at 10*BTDC and accomplish the same thing. It makes the exhaust hotter and the cat function better, burning up the CO and HC and at the same time lessens the cylinder pressure and therefore NOx emissions. In all honesty it was not much dirtier running with timing advance. I just wanted to make sure it would pass easily though. When it was carbureted, I disconnected the vacuum advance hose every year prior to testing (timing was advanced nearly 10* over stock). Retarded timing + leaner air/fuel ratio = pass every time with ease. It was a little dirtier with a Q-Jet on it, but not much. One year I tried to get it tested with a box stock Edelbrock 1405 on it and it was a gross fail. The HCs were 2x the limit and C0 was through the roof. Even jetted to a 1406 it failed. I pulled the Q-Jet off the shelf, tossed it on and instant pass.

[one92rs]

Im hoping to be able to log it when i get home. Then i can post it
On here for yall to see what you can find. Actually hoping something sticks out like a sore thumb.

[EagleMark]

Maybe? That is what we want to rule out. But from what Fast is saying it's probably all the spark I have in your chip... or that and as Buzz mentioned a non efficient CAT. It's amazing how much a CAT can clean up and for the little bit of HP lost it's really just a good thing for the air!