I have a 1999 B4000 that's now stuttering on acceleration and feels low on power. Issue came up with P0304 code, which I thought I had fixed with new spark plugs and coil pack. CEL has been cleared but the problem still persists. Engine idles fine and does not run rough when reved to 6000rpm in neutral.

This problem did also just pop up after replacing the radiator after the old one developed a crack, limped it a mile back to the hose with frequent cooling breaks when temp light came on. Have not checked compression yet... could this problem be caused by a cracked block? 😬

 

How many miles on the engine? Yeah, you could have burned / warped parts. Try a healthy dose of Techron.
You might get real lucky, considering the hot lunch.

 

At 213,000 now. Wondering if I might have a vacuum hose problem with everything I had to remove and reinstall with the radiator. Any suggestions with troubleshooting a possible vacuum leak? I'm going to give the techron a try, then new ignition wires and then compression check if no change.