Help me figure out what to look at on my TBI motor

[sled_dog]

My Burb runs like ass since Saturday. It was running awesome then. Got it stuck, pulled it out(not really pulled, just drove) and now it runs like crap. While driving at a steady speed it surges. It sounds like there is a little puff going through the exhaust, like its misfiring a cylinder or two. Once in a while I will feed it more gas and it will smooth out and feel like I suddenly hit a 20 shot of nitrous. All I can think is ignition issue or O2 sensor. I just put in a 3 wire O2 sensor on Friday. I checked the connector and everything looked fine. Didn't check the heater portions connectors though. Think I fouled a plug? Maybe I need to pull them all and check. Really sucks cause it was really running great on Saturday. Its not too important since shes going to the yard on saturday but I'd still like to hunt it down for future reference.

 

[k20]

sure it aint something as simple as a wet airfilter (dont know where you were wheelin/how deep it was)?

 

[sled_dog]

not deep or really muddy at all. Mostly trail with light mud.

I forgot to note that it is somewhat intermittent. I can't figure out what causes it though. This morning and today at lunch it ran great. Cold this morning, warmer this afternoon. Tonight it ran like crap, and it was between as cold as it was this morning and how warm it was at lunch.

My thought is bad O2 connection, but if that were the case wouldn't it throw a code? Its throwing none.

 

[k20]

Ive had things go bad and not set a code before(temp sensors, o2 sensors, etc). Wondering if perhaps your knock sensor wire got over onto a pipe and is randomly shorting itself out, screwing with your advance?

 

[sled_dog]

that sounds quite possible. I'll look tomorrow. It almost felt like it was detonating so I topped it off with 93 yesterday but that made no difference.

 

[zcarczar]

Check your plugs, wires, cap and rotor, mine had a miss due to a corroded cap and wire, would almost make the truck die it would start missing soo bad some times. But I replaced the plugs, cap, rotor and wires and it runs GREAT now.

 

[Afireinside]

I had the exact same thing and it turned out to be the plugs and wires(changed them both at the same time).that cured it.

 

[jekquistk5]

my k5 did this... it was a plug wire, that had a minor crack in it, and when there was enough moisture in the air it would arc. My guess is the plug wires!

 

[RustBuket]

Mine is carbed and did something similar. One time it was have power like normal (not much lol) and then another time I'd try to go and it would shake badly and have no power at all. I found out that two of my plug wires would move around and then get close to each other and arc so 2 cylinders were misfiring. Also, one of the plugs had a cracked ceramic peice so it was arcing through to the block. Running on 5 cylinders sucks!!! Especially in a 305.

 

[Jonny-K5]

mine was doing that recently after a mud running trip. it was plug wires arching over. i'd check them out or replace if they are old.