I have been fighting a misfire and rough idle problem.

As part of diagnosing a different problem earlier, I replaced the crankshaft position sensor (among many other parts). I did not do a relearn procedure. I do not get a specific code relating to that anyway.

The problem I have is the rough idle and very bad misfires on acceleration under load. If I very vert gradually accelerate it doesn't do this very badly. When on the highway and going up-hill or if theres a head wind... its bad.

I was wondering if my symptoms are indicative of NOT doing the relearn prosedure...

Heres all the parts I've replaced in the last month:

new battery, new cap, new rotor, new distributor, new crankshaft position sensor, new plugs, new wires, new ignition control module, new coil....

I have a new fuel filter to try tomorrow as well as a new pcv valve. Going to check the egr too

 

PROBLEM SOLVED!!!

Never would have thought this was the culprit, but as I was removing the #1 plug to try and do a compression test.... I noticed that the plug was cracked! That explains the ticking noise I heard on the drivers side of the engine. That explains the rough idle and the poor acceleration!!!!!

I just replaced those plugs 2 weeks ago! !? Oh well! I'm just g;lad it was an easy fix!!!!

 

Wish my woes were that simple, but You did make me go back and check my new plugs lol. All are fine. My truck purred until the other day, stalled on take off, ran terribly rough for 4 miles to get home. Replaced fuel filter, air filter, distributor, rotor. First mechanic had it for 2 days, no results. Its at a Chevy dealer today but they just called, no solutions there either. Fuel pressure reads 55 so think that's not the prob either. I've seen posts where experienced mechanics have replaced just about every sensor and wire. Does anyone know the secret to solving my issues without me having to do all that> thanks for any advice.