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?

 

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.

 

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

 

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.

 

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.