heres the deal. becuase the truck was having a hard time starting when cold, i replaced the distributor cap and rotor (which both had some corosion), as well as checked the plugs and IAC. So far this week, no more hard starts, but now the engine pulsates while running hot. during idle a pattern of pulsates can be recognized. when driving under highway speeds, another pattern of pulses can be detected but it is sparatic. often the pulsating shakes the steering column, and a passanger even could feel the shaking.

i have checked to make sure that the wires to the plugs are in the right order. the first time i noticed this was after i removed a plug to check it, and replaced it, and befor i replaced the distributor cap.

thanks

 

Its probubly a wire or plug. Just let it idle and pull off one wire at a time. If it runs worse, put it back on. The one that doesnt change anything is bad. (the wire or plug)

 

thanks, great advice

 

Keep us posted. My '86 does that idle thing, where you see the tach needle move up and down about 100 rpm. Don't notice driving though, it smooths out when you give it a little gas, but bumping the idle up didn't help. Neither did cap, rotor, plugs, wires, coil, ect...

 

Try checking that specific plug wire. I'll bet a terminal was pulled loose, or maybe the conductor cracked or separated.

 

if its the wire can you buy just one wire?how much are we looking at for that?or for all new wire?

the wires are new from a year and a half ago, same with the plugs, but the plugs look great.

 

96 u can also try reading the codes may be other problems TR

 

well i bought new wires, and just had time to install the one that i thought might be broke. well its still doing it. and to make a correction its not so much of a shivering type vibration, which periodicaly is bad enough to shake the truck and stearing column. as soon as i get home, im going to change out the rest of the wires and check that one plug again. so well just have to see

 

i guess hairline crack in plug in cylinder 5 has gotten bigger in the last few weeks and finally got registered in the codes two days ago. cylinder 5 misfire. changed it out today and its funning perfectly now

 

Glad you found it 96Eddie. Gotta love those easy fixes......

 

yeah, 1.50$ is the best kind of fix! the only question that i have now, is that the idle speed is higher now, both out of gear and in gear, then before. could i have bumped something in the engine compartment, or would this just be a result of the new plug wires i installed along with the new plug? should i lower it back down to around 700, its at about 10-1100 right now