Hey guys, I rarely post, mainly because I am a complete moron when it comes to vehicles and I have zero valuable input. I do first want to say thanks to the people who post on here. So much good information even for a guy like me who most of the time has no clue what he is reading about. The time some of you take to explain in detail to help another stranger with a problem is pretty awesome. Now on to my issue. And I want to apologize if this is in the wrong spot to post. I know it has been discussed in other threads, but each one is slightly different than mine. So here recently my truck has started to jerk or miss when cruising or more so when I start up a hill before I step on it to make it shift into a lower gear. Nothing wild but noticeable. I live in the Ozarks and my highway driving involves a lot of hills. So when I approach a hill, you can tell the truck realizes it and then it starts to jerk and miss a little. Then when I step on the pedal to help out and it shifts or whatever it goes away. I notice this mainly on the HWY but it does do it in town sometimes also just not as noticeable. The truck has 150k on it. The guy I bought it from kept all service records. It had a full tune up 25k ago. Plugs, wires, fuel filter, distributor cap, fuel pump. The only thing I have done to the truck was put bigger tires on it, which has affected the power some and has caused, or at least it started after I put the tires on, a tiny bit of spark knocking or whatever you call it, which I was told was fine.....but maybe that is incorrect I don't know. I read another thread where guys were unplugging the EGR thing and it magically took care of the problem. I did that, and it does not seem to have helped in my situation. Thanks for any input. I don't feel like going to my local mechanic and just throwing money at random things, so I figured I would post here first. Thanks.

 

If the tuneup used conventional (non-platinum or iridium) spark plugs, at 25k they are due for another change. If it still spark knocks with new plugs, the timing is over-advanced or you need to use higher octane gas.

 

OK thanks for the response. I have no clue what type of plugs were used so I guess I will get a new tune up. Not sure what you mean by timing over-advanced but I'm sure my mechanic will. Maybe I will get lucky and the tune up will fix the jerking also.