Gents,

I have the above vehicle. I bought it secondhand from the city of Sacramento about a year ago. It only has 53,000 miles on it. I have all the City Maintenance records on it as well as the CARFAX docs on it.

When I first got it, I noticed an issue with the way the engine was running, so I hooked up my reader and it told me I had a bad throttle position sensor. I replaced it and the engine ran fine and the "check engine" light went out.

About 5K miles later, I started getting a stutter in the engine, especially at idle, or if I step on the brake and accelerator at the same time with the truck in Drive, it will stutter under the load, especially around 1500 rpm. If I push the throttle harder, it smooths out.

I hooked up the reader again and got a P0301 code -- Cylinder 1 Misfire. I pulled the plug and looked at it and it appears to be fine -- correct gap and no signs of oil fouling, cracked insulator or anything.


Since this is a work truck and I don't want to have to spend a lot of time or money on it, since I am retired for the most part, what do you think is the most likely suspect?

A single-cylinder misfire is *almost always* gonna be ignition... plug, or coil, or on an older vehicle (like a 4cyl Dakota) distributor or wire.

Before spending money, you can move stuff around...switch the plug with #4 and see if the problem follows, then move the coil. If it's a distributor, just replace the plug wires and cap & rotor. It's cheap, it's old at this point, and it probably needs it anyway.

It could also be something like a clogged injector, or problem with valves in that cylinder, so trying to narrow it down between ignition or mixture is the cheap/easy first step.

Be happy it's a city truck and not a county truck. Those asshats in the county don't take care of their vehicles *at all*.

[This message has been edited by thesameguy (edited 02-15-2021).]