Okay my truck has been giving me trouble for a few months. It idles fine but when you go to drive it it sort of boggs down. It seemed to me like it could be a fuel issue so we've done a few things we thought might help. I've replaced the in-line fuel filter, which was full of brown goo, dropped the tank and cleaned it out, replaced the in-tank filter which was brown as well, replaced the spark plugs, which were pretty old and quite nasty, and cleaned the cap and rotor. It idles beautifully now, doesn't miss and sounds better than it ever has, but when you try to drive it it keeps jerking and bogging down. I'm at a loss, can anybody help me here?

 

Sounds like you had some nasty stuff in the tank. Maybe try running some fuel cleaner through the system. If the junk was in the tank and filters, it's probably in the injectors also.

 

i second what Chevy Lover said. try some STP fuel injector cleaner or Seafoam. id rather STP than Seafoam beacuse Seafoam can put carbon deposits on the spark plugs. of that im reasonably sure but please dont quote me. also have you checked your transmission fluid, my truck leaks tranny fluid and i havent been able to fix it myself and i dont have the money to get it fixed but that has caused some problems like what you described for me.

 

I also agree with that. I always use STP

 

Well the guys cleaned out my EGR and it seems to be running a bit better....only jerks around when you're not giving it a bunch of gas, which is usually how I drive, LOL....so unfortunately it isn't reliable enough to take to work and back. And I didn't happen to think about a clogged injector...good thinking guys! I'll try cleaning them out and let you all know what I come up with!

 

Sounds like you are planning on pulling out the unit it self.
Iwouldn't go that extencive.I would try some good injector cleaner first.I have never used STP, butI would recomend Lucas, or B12 or you could go crazy, and have the dealer use some BG fule injector cleaner, witch they inject at the fule pressure test nosle, (there is a differnt name for that butI dont know it) good luck.

 

I haven't seen it mentioned yet, but check your upper intake, looking through the throttle body hole. If one side is clean and the other side sludged up, you could have a leaking fuel pressure regulator. The fpr works off of manifold vacuum, so it stands to reason that when you are trying to accelerate (thus pulling more vacuum), the fpr is dumping/leaking fuel into the intake, which causes a flooding/stumbling/over rich problem. How's your gas mileage, BTW? A bad fpr usually contributes to low mpg's.

 

Haven't been able to drive it far enough to get an accurate gas mileage estimate. I'm gonna look at these things today, with it being my day off.

 

I've been lately having the same problem myself. I've been driving this truck w/o any problems for about 2yrs, but in the past 6 months i've had it buck and stumble, backfire in the headers and even through the intake. I've sprayed carb cleaner in random ports on the carb/tbi section. It's odd because some days it drives like a champ, then suddenly it does this leaving me stuck in parking lots or on the side of the road. It seems if I let it cooldown after an hour or so, then it's fine again. When this stuff first started it happenened like 6 months ago, and then went away for months, but now it's more frequent as like a couple times a week.

 

I know this is an old thread, but I just wanted to update two of the items I found that fixed my problems like this.

When I first got this truck, it would buck and stumble at normal throttle, then take off like a beast. I ended up being that the fuel pump was down on pressure, which wasn't the easiest replacement. This was back in 9/05 per my sig.

Another time I had something happen just this year that was similar to this where it had the same symptoms...ended up the nipple on the inside of the distributor cap had simply ground down to nothing, so it wasn't contacting the distributor. I had done a complete tune-up 5/05, yet the cap degraded in that short amount of time. As of this week I ran SeaFoam through the vacuum booster, and it had a highway cruising miss now. It was fine before the SeaFoam, so i'm trying to understand what could have happened. I replaced the Bosch plugs (didn't know about Delco's at the time) w/ the 45's (slightly hotter than stock based on a recommendation based on my driving style) Delco's, yet it still has the highway miss...so time to start searching the boards.