Hey everyone. So I decided to change the plugs on my 01 4.8L, when i went to pull the wire off the plug on the passengerside at the back ( by the firewall) the wire pulled out of the boot. So buddy gave me one from his 03 4.8L but its about an inch and a half too short. The truck would run but not very well, if I was accelerating hard, sometimes the engine light would come on and blink, and then go away, so I ended up getting the proper wire for it but it still kind of jerks when shifting from 3rd to 4th and every time it happens the engine light blinks at me its hard to tell but its not shifting at the proper rpms. A buddy of mine told me the plug may have fouled up cuz the last plug wire was too short, had a ****ty connection, so I'm gonna check the plug in a few and see if I can't clean it up. Any other suggestions would be great, really appreaciate the help!!

 

Ok so i just pulled the plug out that i thought was misfiring and another out, they both look the same. I changed them around and took the positive off the battery and even drained the charge on the negative side. Took it for a ride and same problem.. At 95kms/h it revs at 2000rpm...

 

Ok,so. I got all new ngk plug wires and the truck seems to run fine, and accelerate fine until wjen ill be doing about 80km/h and it will be in the last gear but when I begin a slight incline on a hill, the truck won't shift down it will jump back and forward slightly, its actually quite a jerking, when I get on the accelerator it shifts right up, almost like its missing a gear in between. So I don't kno. I'm going to chance out the fuel filter and get the transmission oil and filter changer its been 2 years since its been done, if anyone has anything to add please don't hesitate.

 

Well Im pretty sure its gonna be a ignition problem. Go see if you can pull up any codes. I cant remember what it means when the SES light flashes but i'll check.

 

Then again come to think of it, the SES light is flashing cuz of a misfire. After running it for a while, check all of the plugs to see which one is doin this. Could be a bad coil, bad cam sensor, clogged injector, something minor. Checking the plugs will narrow it down which cylinder it is.

 

AC:

guess this has been said before but at 95K i would have tuned up the truck using all AC delco parts.
so many times you hear of someone who uses other than ac delco parts and has problems.
then have to spend extra money buying ac parts to get going again.

when you changed plugs you should have planned for the ac delco wiring kit.

i understand off brand parts may have different ohm's etc: that makes the computer go wild.

just my two cents!

i had my old chevy tuned up at 90K with all ac delco parts, it was running good and it continued to run good after the tuneup, that is what you want.

 

Possibly bad intake gasket? I think the code for a random misfire is p0300 if you can pull the code. Some auto parts store loan out scanner if you don't have one. If it's a random misfire changing plugs/wires around won't help as your pulling coolant into random cylinders. I think if you pull a p0301 etc it will give you the specific cylinder that is misfiring but i am not positive of the exact code#.