Country_Feller

Hey there, as the title says, my truck will occasionally run weird, and stall out. What it's doing: When it shows symptoms, what it will do is when you accelerate, the engine bogs down and acts like it isn't getting enough fuel. When this happens, I let off the gas, alternate the gas petal in and out, and sometimes it will clear up and be alright. Also, when it does this, it has a high likely hood of knocking and clunking, although this sometimes doesn't happen. I have recently given it a tune up, including plugs, wires, cap, rotor, and a new fuel filter. I have not changed the distributor, or the coil. One more thing it does. When you have the gas down, but the engine is NOT under a load, it will knock then, too. Like, when you're going down hill, but you still have your foot on the gas slightly, or when it is in park and you hold it at about 1800-2100RPM's. The truck sat for 4 years before I bought it, and I know the old fuel probably isn't completely out of it, yet. One more thing to tell you (that I can think of.) The fuel pump was awkwardly loud tonight when it was showing symptoms, which makes me think the whole thing is fuel related. I have NOT replaced the fuel pump, nor cleaned out the fuel tank. I ran some fuel system cleaner in it, then replaced the fuel filter (had CHUNKS in it!) and then some Seafoam, but alas. Nothing has conquered this problem. Is it timing, or is it fuel related? Could a lack of proper fuel/air mixture be causing the knock? Could it be BOTH fuel AND timing????? (I sure hope not. Running out of money to throw at this thing.) Thanks for all the help, and sorry it's so wordy. Just trying to describe, to the best of my ability, what it's doing.

Country_Feller

Oh, another thing: When I got it to work tonight, almost immediately upon getting into the parking spot, it started acting up. It started hesitating, and this time, the alternating of the gas petal in and out didn't level it out, and it finally stalled. Before it got too bad, I also noticed that the fuel pump was loud enough to hear inside the cab with the engine running. Once the truck finally stalled, I immediately tried cranking the engine, but it would not start well, and it ran like crap. Shut it off myself, and primed the fuel pump about 5 or 6 times, and not only did it start immediately, but it ran level. Like, perfectly. Smooth. Could jab the gas, and it would respond immediately. It still had that knock when I held the petal down, though, but it ran smooth. And ONE MORE THING: When listening to the fuel pump, instead of the typical "whine" you hear when a fuel pump is on, this one sort of buzzes, or hums. It is much lower pitched than a whine. Think it's indeed going bad? And could my engine stalling problem be timing AND fuel related? (I hope not.......) Again, thanks guys!

sdmartin65

If it were mine I'd guess pump going junk or clogged injectors. Id start with some pick and pull injectors that I knew were fresh. Unless its cheap to clean the ones in it now, haven't had to do this so not sure of best route.

Country_Feller

It's definitely the pump. It started working intermittently on me earlier today. Gonna change both pumps. Also, I think the crank bearings might be bad. Gonna tear the engine apart and check those, and the rods. I think that it might have bent a rod as well, as it ticks at certain RPM's.

brawlincollin

The pump is deffinwtly bad. As for the wierd acceleration issue, after you replace the pump and it still does that occasionally it could be the TPS ( throttle postion senser) and I would also check ignition timing, that can also cause knocking at certain rpms

brawlincollin

Also check the cat, could be plugged up

Atomic Monkey

I've had this happen and it turned out to be the TFI module.

VettsnFords

If you change those pumps i would change the tanks to plastic ones if you have the money. those metal ones are known to leak

Country_Feller

All good advice, everyone! Thanks! As for the plastic tanks, oddly enough, this truck has them. I found out that it is a couple of rod bearings that I am hearing in my engine, and the tremendous "knock" or "thunk" that I am hearing is the wonderful sound of VERY heavy pre-detonation. It is running way too lean from lack of pressure. Another fellow told me that the "sock" around the fuel pump is probably clogged badly too, as when I replaced my fuel filter, it had enough crap in it that hardened together that you could shake the filter, and it would rattle! That's bad! Not to mention the stuff that freely flowed out of my fuel line from the gas tank... I am not running the truck anymore until I can afford to replace both fuel pump modules, and clean out the gas tanks, via a chemical flush.