Hey 3gen fam,
I have a '92 camaro 5.0 tpi/5 speed. I've only had the car for a few months and have been tuning to original spec since I bought it. It was a solid car to start with but have done a major tune up, installed new clutch, temp sensor, o2 sensor, idle control valve, dist cap and wire and plugs. It runs and idles fine except for sputter at idle and vibration in 1st and second gear. The clutch is still fresh so I try not to go over 3,500 rpm but sometimes at about 3000 I get a vibration in 1st and 2nd gear. I know that if running on 7 cylinders the engine does not shake much because the smog shop had left off a plug wire when fixing an exhaust donut. Even when I revved it up at the shop, the engine did not feel like it was missing. So i'm wondering if I may have a misfire and wouldn't feel it until higher rpm's. The mileage kinda sucks and I'm not sure what else I can do to improve mileage or check for a misfire without pulling every plug and checking spark. I'm new to 305's and love the low end torque but am I running on 7?

thanks for the comments

 

is it giving a check engine light?

 

no check engine light. i once got codes for a low voltage tps and egr valve but that was probably due to the engine fans being wired direct and the ecm thinking the engine was running cold. I check the egr last weekend because I was getting a surging idle but it looked clean, held a vacuum and the diaphram looked good. I never changed the tps because on a scope it had no spikes and the min. voltage was at .67 volts at idle and 4.3 at wot.
what kind of code would a misfire give?
I changed the 02 sensor to help with mileage and ide and the temp sensor as well.

For the sputter I have not changed the coil, distributor or elec. module, what else might cause it?

Possible a worn timing chain, it has 200k miles???