New Member here. I have a 92 Camaro TPI 305, 5 speed. It failed recent emissions on idle. it runs rough at idle after warm up but seems responsive and smooth everwhere else.
There are no codes. I Just installed TunerPro on my laptop and got a usb ALDL cable and downloaded a sample. I am trying to establish the desired or known values that Ii should have such as o2 voltage, idle speed, timing ,etc to compare. I can't seem to find these. I thought I saw a chart with the parameters on the net. I get about 500-700mv on O2. I pulled and cleaned IAC, cleaned throttle body, and installed new O2 senser. The distributer and plugs were replaced last yr. It does seem to run smooth during warm up, or first starting. Will test fuel pressure, but I'm thinking a leaky pressure reg diaphram. thoughts? TunerPro experts?

thanks

 

If the regulator diaphram was leaking, you would smell fuel from the engine compartment. You can disconnect the vacuum line going to the regulator, if its wet with fuel, then the diaphram is leaking. As far as reading the values on Tunerpro, I'm on the same boat as you, I can't figure out some of the values I read there like the air flow and some other things. As far as I know, the o2 sensor should jump around between 0.1 - 0.9 I think.

 

Can you share with us the results of your emissions test?

-- Joe

 

If the engine still has the OEM stock Multec injectors I'd swap those out, first thing done.

And welcome to TGO.

RBob.