i put a tune up on my truck last week. new ngks. wires cap and button. every now and then i would hear somthin like a spark knock when ever i get on it pretty good. but its been runnin fine other then a slight shuttering feelin around 60 mph. last night i took off from my house and really showerd down on her i held first and second gear to around 5 and a half grand then shifted in to 3rd and let off it. right after i let off it i could hear that rattle like a rocker arm when ever i touched the gas. so i drove it really easy for a couple miles to the store. when i got out the store the check engine light was on . so i pulled my scanner out and ran the codes right there. cylender 1 misfire. i erased the codes and it aint came back on yet. any ideas on this mess? thanks guys also how can the ecm tell me its cylender 1 misfire when it doesnt have coil packs. or is it just tellin me theres a misfire some weres.

 

ok so today i took the ngks out and put in a set of champion plugs. took off to go to the store and noticed my gas milage came back up from 15 to 17 mpgs. well i got behind a slow car so i kicked it and passed them. right when i got around them it started rattlen again like a rocker arm or spark knock like ive been sayn. by then i was runnin about 70 and i could feel the truck buckn like it was missin again. just as soon as i got to the store bam check engine light came back on. i scaned the codes again and surenuff cylender 1 misfire detected again. wtf!! does any one know what this could be or should i just go to anouther forum?

 

Check your rotor. I have seen them shear the locator off and cause misfires. I would think it would cause a misfire on all cylinders though. Wires are all seperated and good? Good luck, keep us informed.

 

the cap and rotor are brand new. and i dont under stand how it can tell me misfire on cyl 1 when it has a rotor and cap not coil packs

 

I am at a loss, sorry.

 

did you gap the spark plugs before you installed them? have you check the spark on number 1 spark plug? could have a bad spark plug. i have had 8 bad champion spark plus with my 81 and 2 of them were brand new.

 

yea i always check my gap befor i install plugs. the ngks i just took out didnt even have 150 miles on them. and there isnt a dead miss in the motor just a little shutter some times when im barly touchn the gas around 50-60 mph. and it you think about it theres no one for the ecm to tell me its cylender 1 misfire cuz its got a cap and not seperate coils for evey cylender.

 

have you done a compression test on all the cylinders?

 

nah i aint got that deep in to it yet im more worrie about this rocker or lifter rattle i keep hearin when i throw the coals to her.

 

im thinkin it could be a weak lifter. it only rattles when i really get on it so it could be losen prime then idk