Engine is misfiring after replacing distributor

Hello,

This could be either a problem with your Idle Air Control Valve (IAC) or it could be an intake or vacuum leak. The IAC is controlled by your vehicle's Power-train Control Module (PCM) and lets air bypass the closed throttle plate to keep the engine idling. When the IAC valve goes bad it will fluctuate and cause this problem. Also an intake/vacuum leak with suck unmetered air into the intake causing your vehicle's idle to "search" up and down. A good way to check for an intake/vacuum leak is to get a propane torch and barely crack it open making sure not to ignite it. Start your vehicle and let it idle. Move the torch all along the air intake tract, throttle body, intake manifold, vacuum and Evaporitive Emission (EVAP) lines. When the leak is found the engine will rev up as the propane is sucked into the system and burned in the combustion chambers. I have included a test guide for you in the diagrams down below. Also I have included a couple of links for you down below to go through.

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please go through these guides and get back to us with what you find out please.

Thanks,
Alex
2CarPros