CrashDriver
Newbie
Hi, this is my first post on this forum; I have a 1994 K2500 with a TBI 350. Before I go down a bunch of useless rabbit trails of part purchases I figured I'd see if anyone has a clue about my issue on here.
So fairly recently I started to notice the truck was running... I don't know if I would quite describe it as 'rough' at around 50-60 mph, but it seemed to slightly struggle with throttle and kind of 'chug' a little.
It seemed to get worse over time, and the transmission was feeling like it was shifting weird. And it started to sound like it was backfiring out the intake when I was really going hard on it as well.
Then the other day just to test I went from a stop to WoT all the way to 60 mph - it was really rough. It didn't want downshift and it lugged hard and when I got up to 3,500-4 it actually started to knock I think. It didn't sound to me like a 'ping' really, it was more like I could hear each stroke clearly.
On a hunch I replaced the ISS and VSS sensors on the transmission (4l80e), and that helped greatly and it shifts normally now.
I can throttle it hard on the road and it's pretty good, the engine runs completely normal, except when I go from a complete stop to WoT. It shifts right but it still struggles, either backfiring out the intake or knocking or what, it's hard for me to tell since this is my first time dealing with engine knocks.
I'm wondering if this could be related to the engine not getting the right fuel mixture, or spark? my uneducated guesses are leading me to think I may need a new MAP sensor or TPS - or even plugs and wires. What do you guys think?
So fairly recently I started to notice the truck was running... I don't know if I would quite describe it as 'rough' at around 50-60 mph, but it seemed to slightly struggle with throttle and kind of 'chug' a little.
It seemed to get worse over time, and the transmission was feeling like it was shifting weird. And it started to sound like it was backfiring out the intake when I was really going hard on it as well.
Then the other day just to test I went from a stop to WoT all the way to 60 mph - it was really rough. It didn't want downshift and it lugged hard and when I got up to 3,500-4 it actually started to knock I think. It didn't sound to me like a 'ping' really, it was more like I could hear each stroke clearly.
On a hunch I replaced the ISS and VSS sensors on the transmission (4l80e), and that helped greatly and it shifts normally now.
I can throttle it hard on the road and it's pretty good, the engine runs completely normal, except when I go from a complete stop to WoT. It shifts right but it still struggles, either backfiring out the intake or knocking or what, it's hard for me to tell since this is my first time dealing with engine knocks.
I'm wondering if this could be related to the engine not getting the right fuel mixture, or spark? my uneducated guesses are leading me to think I may need a new MAP sensor or TPS - or even plugs and wires. What do you guys think?