well heres the story. lately my cars been skipping a cylinder, but im not sure which one. net every cycle, but you can easily tell once in a while when its at a smooth rpm, it does a slight fart. and if your watching the motor while its running, it does a quick shake when it farts. ive checked and tested all of the plugs, and they are all fine. heres the only changes made recently. like a week ago i tightened a loose rocker only about a 1/4 turn to tighten it up. but heres the real change, i needed my old mans truck to pull the lawn equipment. he brought it home at 6 o clock,. i took it after that and went into town. every time strain was put on the motor liks going up hill, i would clearly here it pinging. this was knew because i mentioned it pinging before, but i had already backed off the timing so it owuldnt do it anymore. well i get back to my house and tell my dad what it was doing, and then asked him what gas he put in it. well he did put in 89, so i went and filled it with 93 and the pinging stopped. im not sure if it started skipping a cylinder after i adjusted a valve or after it was pinging a lot. what is more likely to be the issue? after seeing that the plugs were clean, i was thinking of doing a compression test, and seeing what that says. what do any of you think. thanks for any help.

oh and by the way, its gas mileage has seemed to decrease and it lost a lot of power. the exhaust gas is crystal clear.

 

You may have tightned the rocker a little too much and the valve is hanging open. Are you using the proper procedure for adjusting valve lash? The other possibility is that the pinging damaged the spark plugs, such as cracking the porcelain which is hard to see. Also, pinging for a long time can even produce broken pistons. Quick check is to open the oil filler while the engine is running and see if puffs of vapor come out of the filler opening.

 

yes actually vapor does puff out of the filler hole. what i do kno is to first jstu loosten the rockers until they can barely wiggle, and while the engine is idling, slowly tighten them until they dont tick or wiggle any more. my only issue after that is once they dont wiggle, do i turn it half a turn or a 1/4 of a turn?

 

Hydraulic cam? I would check the compression, could be alot of things, cam, lifter, ignition compression test will indicate hole in piston or burnt valve if it is bad result.

 

With the engine idling tighten till clicking stops and add 1/4 turn to preload the lifter. After this do a compression test.

 

alright i did re-adjust the valves on just the left side where the puff was coming out. it didnt get better immediately but i drove it around that blockj at a steadt 3500 rpm to fill the lifters back up properly and hwen i got home it had a normal healthy cammed motor idle, with no vibrations. a compression test is still a definite for the future.