OldFaithful

Alright so I just picked up an 88 Firebird and figured the first thing I would do on it is a tune up. The first thing I did was I swapped out all the spark plugs for new ones, and when I started the thing up after putting in the new plugs, it ended up having a misfire. I then bought a new spark plug, found the cylinder that was misfiring then replaced the plug with a new one. This took care of the misfire but now I have a different problem completely. Now when I'm driving I get a steady jerking motion while driving. It's almost like it is misfiring but when I listen to the engine I don't hear any cylinders missing. I continued with the tune up, changing the plug wires, the distributer cap and rotor, and I will be changing the fuel filter soon. Since none of the electrical stuff made a difference I'm thinking this could be a fuel delivery problem. What do you guys think?

OldFaithful

Also, I forgot to mention that me and my dad cleaned out the throttle body before we took it on a test drive after I switched out the old plugs. I've heard that sometimes cleaning those throttle bodies when they're old they wont work as well. Not sure if that's true but I figured I would mention it.

DeltaElite121

when does it start showing symptoms? How is the idle quality? Had it shut off on you, or just kicking and bucking?

OldFaithful

I shows symptoms when its hot or cold, doesn't seems to make a difference at all. At idle its fine, doesn't shut off or anything. The kicking itself is pretty subtle, and it's most prevalent when cruising at around 55 mph.

OldFaithful

Ok well I figured out the problem today. I switched all the plugs out again and now she's running nice and smooth. Not sure what the problem was but I think the plugs may have been gapped wrong.