Hey guys, i have a 1995 GMC sierra full size truck with the 350.....well it has developed a miss at idle but when its put in gear the miss is gone...So i go in and do the general maintenace, replaced plugs, wires, cap and rotor...but the miss remains....I did notice what looked to be a little corrosion on the coil...could that be my issue or you guys think i got a vacumn leak?

 

What brand plugs, wires, cap and rotor?

 

i had that in my 94 i have when i was in high but it was a burnt valve

 

AC delco plugs...dura last cap and rotor from autozone and i dont memeber the brand of plug wires from autozone too.

Dont say that....lol...this truck has been babied all its life...95 with only 100, 178 miles



It misses only in Neutral and in Park...in any gear whether ur moving or not theres no miss.

 

hook it up to a live data scanner that can read the sensor values.

 

mine was babied also!!!!! it had like 140 something or 150k on it one of the 2(its got 169,001 now) but i cheacked out all plugs had good spark thought it coulda been timing chain but didnt check then i asked my dad and he told me too take the heads off and when i did burnt valve out the ***!!! lol so got both heads re-surfaced and all new valves in both of the heads for 500$s, and now that thing runs like a brand new one which it sits under the shed all the time since that happened lol but that could be a good possiblity if all else fails,,, and mine ran fine also only when it was just idiling also u could tell it

 

You need to lose the Duracrap stuff and get ACDelco. And for plugs....NGK or ACDelco only.