I took my 87 coupe through Air Care today and it failed!          ;       This was the first time on the road for the car after rebuilding the Duke. I drove over 100k trying to burn the old gas in the tank, This moved the needle on the guage just over an 1/8. I gave up and tested the car with 1/3 old gas.         &n bsp;         &n bsp;         &n bsp;         &n bsp;          On the driving test I failed NOx - 2584. on a max of 2378.  Not bad but on the idle test I did an HC of 1194. on a max of 306.  Oops.  I'm thinking a new cat may not fix this, What do you think?

Last week I past both 85s through Air Care with no problem but the 87 dukes are a little harder to pass. Irwin was having problems with his 87 as well.

The plugs are ngks from the Lordco computer. I'll pull them for a reading later but I think that I will burn the old gas off before I test it again. Maybe that will loosen the engine up a bit as well.

One think I know is Air Care is a pain in the ______ !   Between Ang and I we have 5 car to test every year just to drive then once in a while. They need a limited use insurance that is Air Care free. Like commercial trucks , pickups over ____gvw, and motor cycles.

Driving test- Hydrocarbons 91 on a max of 226.

                   Carbon Monoxide 0.38 on a max of 1.64

                   Oxides of Nitrogen 2584. on a max of 2378.

Idle test-     Hydrocarbons 1194. on a max of 306.

                   Carbon Monoxide 1.06 on a max of 3.59

My 85 2m4 with 250,000+km tested much better and makes me think burning oil is the way to go.

Driving test-  HC 33. on a max of 234.

                     CO 0.00 on a max of 1.68

                     NOx 275. on a max of 2432

Idle test-      HC 24. on a max of 390.

                     CO 0.00 on a max of 4.43

Maybe I should keep this motor for passing Air Care.

I used a timing light to watch the spray pattern of the injector. The fuel gobs matched the pops coming from the tail pipe. I will replace the injector and retest the car.

On a side note, the car has a 86 Isuzu 5 speed. At 125 kmh in 5th gear the engine is reving at 4,000 rpm. This is a Fiero trans but 410 gears on a 5 speed? (All other gears are low as well.)

Sounds like you ended up with an Isuzu that was originally out of a front drive sedan, same issue I had with the front drive trans axle in my 4.9.   There seem to be a bunch of different ratio Isuzu's out there, and only the genuine Fiero Isuzu had the good highway gears. 

As for knowing how to tell, the only way I can check them is by turning the input shaft and watching the output shaft rotations.   No one seems to know what numbers are what on the outside of the trans.