I am doing some troubleshooting. My idle seems a bit rough, smells rich, and it takes a bit longer to start.

When hooked up to a snapon scanner, in "special" mode (10k resistor mode ... idle at 1000 RPM),
- I am getting air flow ranging from 7.6 to 8.2 (sounds high to me).
- My IAC ranges from under 10 to maybe 14 or 16. (shouldn't this be higher?)
- TPS is 0.50
- block learn is 134
- injector pulse with was 1.4

This is the second week I have had it out since parking last october. During that time I changed my air box around, a bit more restrictive than before. I also re-torque the intake as a couple bolts came loose (aluminum heads and antisieze!).

Are my readings normal? It ran great in the fall.
It is a 1987 5.7L setup. stock prom, ZZ3 cam, edelbrock heads, ported here and there.

Mark.

 

Mark, I'm not familiar with the "special" mode as I use an Auto Xray, but I'll assum the data is comparable. Typical airflow #s for my car are 5-7 g/s at 600-750 RPM. BL of 134 indicates the computer is adding fuel to get back to stoich. The IAC counts look low to me as well. One thing to check is the IAC counts under normal idle conditions. Mine are in the range of 10 counts are 600 RPM. Wouldn't surprise me if they're zeroed out in your case which will reduce the life of the IAC valve and could account for idle problems. If that's true then the fix is to reset the throttle body minimum air setting.