Hesitation/stumbling under load

1994 GMC Sierra SL 4X2
4.3L V-6 Auto

Sorry this is so long, but here it goes....

I recently have been having some stumbling issues. On the way to work the other day the truck just died on me at a light and was hard to get started. Then engine would turn over but just wouldn't start up and run. After a few moments I was able to get it to run and "limped" it into a parking lot. It was raining like crazy so I didnt get a chance to pop the hood and do a visual. After waiting several minutes I was able to start the truck again but had to stay on the pedal to keep it running...it just would make it at idle. I made it to work and let it sit till my first break. I checked it out and it cranked right up and seemed to perform well except under a moderate to heavy load.

I changed my plugs and wires today (Bosch plat. plugs gapped at .043 / Accel 7MM wires) The truck seems to run a bit better but still weak under load. It feels like I am pulling a huge parachute behind me not allowing me to gain speed. I also changed the oil added a new air filter and filled the truck up with 93 pump thinking maybe this would help..still no go :sad:

The only way I can describe this is that the truck hesitates and bucks. I can easy her out the drive and slowly gain speed if Im not attempting to accelerate to fast. I mean Im getting blown away by Kia's here and they arent even trying..LOL

I pulled codes 32 and 44 from my GM diagnostic thing -a-ma-jigger. The book says :
32 - Baro switch / EGR valve
44 - Lean exhaust indication, o2 sensor voltage stays low after 1 or 2 minutes of engine run.

In addition, FYI...I had my fuel pump replaced a year ago. After a few months I noticed I was having a strong fuel smell at the fuel tank (raw fuel). There is no leakage if it sits, but I was told by a couple peeps that when I take off under moderate acceleration, they see some liquids dropping from where the gas tank sits.

I am requesting some insight in what the potential problem might be. Also if these 2 listed parts above are needed what is an approximate cost of each and wheres a good place to shop?

Thanks in advance for your help. :thumb:

Sounds like a fuel pump failure to me. All the symptoms point towards the pump. You may be dumping fuel out the filler hose under acceleration or the seal for the fuel pump may have not been properly installed. Either case can cause water to contaminate the sock filter in the tank and cause it to collapse. I'd yank the bed off and switch the pump out and inspect the fuel tank for water contamination.

Damn...take off the bed! I wish I could but I live in a condo assoc. I could get away with the small stuff. I might have to take this one to the mechanic and get raped on labor charges :bash: I might as well order the stuff I need.

Whats up with this egr thing...could this cause a problem too? I have mine blocked off in both my Stealth TT and 3000GT VR4. I blocked it off in thos
e cars just as a convience cause it always has to be removed.

Any suggestions on where to buy:
Fuel Pump
Fuel Filter
o2 sensor
EGR Valve
:jump:

my old s-10 with a 4.3 did the exact same thing, threw code for runnin lean, turned out to be a Worn out TPS (Throttle position sensor).. also look for vacum leaks, just my :twocents:

cool..will do

Well I found a fuel pump (Venom Series ) on Summit for 179.99. Its a 90gph pumper. Is there anywheres else I can shop to find a different pump at possiably a cheaper price?

I also want to change out the fuel filter (which is the original one "232K miles on it"). I might have to just go to the parts store and have them order me one then jump across the street and have the shop install them and save the 10% they charge on top of cost..since I know this is what theyll do anyways :bash:

Quote:

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I also want to change out the fuel filter (which is the original one "232K miles on it"). [/b]

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:eek: :eek: :eek: :eek: :eek: :eek: HOLY SHIT! change it already :tantrum: :grr:

LOL....

After 2 days of searching for correct fuel filter I got it changed.

Truck is running smooth as silk and I can spin my right rear dub from a stop :jump: