Ok so I've changed spark plugs,wires,distributor cap,rotor,fuel filter, and ignition coil. Throttle body was severely carboned along with the iac. Got some cleaner cleaned them up real good. Reset the computer and did an idle relearn. CEL came on as soon as starting the engine. Still running rough. It's not smoking just has a little bit of a rough idle and hesitant upon acceleration. Runs smooth and fine when idling up to 2000 rpms. Release pedal back to running funny. Any ideas. I've looked onto others posts with similar problems. Is it my fuel injectors or do I need to get a new iac valve bc cleaning the old one didn't work. I love my blazer but its giving me a headache 🤣😂

 

Did you make sure you put the distributor in right? You gotta have the engine in the right orientation (cylinder 1 TDC) and when you put the distributor in, you have to mark the old distributor and use that as a reference when putting in the new distributor. If it is a tooth off, it won’t run right.

There are lots of videos on YouTube, and a lot of how-to’s on this forum, so make sure your distributor is installed right.

 

I didn't change the distributor itself just the cap and rotor. Although it probably needs a new distributor bc one of the holes for the screw for the cap is broken so it doesn't keep the cap secure. I just ran 2 bottles of injector cleaner through it this weekend and the cel is still blinking and still has rough idle and poor acceleration. My code reader says misfire on cylinder 3. I hate to have to do it but it might be going to the shop soon.

 

The conventional wisdom on the forum is that only ACDelco parts will do for the cap anf rotor.

That your cap is not secured well suggests to me that considering the sensitivity of our ignition system to the cap and rotor parts used, that a loose cap could easily be the problem.

By chance is the wire for plug 3 go to the terminal on the cap near where there is no hold-down screw?

BTW, if you do remove the distributor, mark on it the position of the rotor and do not move the crank. Know that sometimes the driveshaft for the oil pump might need to be manually rotated back a bit to get everything to align correctly. I had to use my biggest flat-blade screwdriver to do that and get my distributor back in.

 

Double check that the spark plug wires on the drivers side are installed correctly. The cylinders are numbered 1-3-5 from front to back, but the cap is numbered 3-1-5 from front to back.