Chevy S10 Sputters on the Highway. Feels like it someone is tapping the brakes,...

[Donny J]

...and I THINK I heard misfire.? The S10 sputters on the Hwy around 55+, I tried to go as fast as 85 and it didnt go away so I slowed down to 70, which gets you ran off the road on the FL turnpike.
-Check Engine Light came on w/ 3 codes: Weak signal from TPS sensor, EGR valve, weak signal from Fuel Pump
-I bought a new fuel pump assembly and it didnt help at all
-Truck idles, and drives around town perfectly
-Started a couple of days ago on the way down to Miami, didnt stop on the way back to Orlando
-Craziest part, I tailgated (almost at a dangerous level) with a semi truck for an hour and it drove perfectly, AS SOON as the semi exited and I was left alone the problem came right back

I dont want to guess and spend money on parts I dont need, especially since I already bought and installed a fuel pump.

I REALLY think it is a wiring/bad wire problem. What else could it be, or how do I find a bad wire. Where should I start looking???

This thing has me flat out stumped...

BTW, S10 for sale LOL

[Ski-Doo Man]

I had this exact same problem with my S-10. Turned out to be a faulty/fouled spark plug (champion). I had just replaced them about a week previous, so I didn't think that could be it. I replaced the spark plugs (I used NGK this time... gap them first!) and it fixed the problem.

Remember, always start with the cheapest solution first and work your way up!

[db667089]

Your EGR may need to be cleaned. Did you replace your fuel filter? Make sure gap is correct on spark plugs...it's critical.