thats a good thing right.................?

 

lol...hell if I know....runs perfect so we'll find out over time I guess.

 

Just an update. I havent put a lot of miles on her, but I have been driving her a lot around the farm and in between a couple mall towns maybe 20 miles apart several time, and to work a couple times which is about 80 miles round trip, if anything the sound has gotten better... cooler weather a factor? I dunno. However, I am going to have to drive her for the next few days to work once again.. the damn water pump went out on my Tahoe.... again! I just replaced it last summer. At least I bought the new one with lifetime warranty, so the part wont cost me anything... so... back to driving ol reliable.. my 18 year old, 260,000+ mile 1994 f150. I have GOT to fix the body on her and get rid of all the rust, still thinking this may be my winter project, if my CHEVY can be reliable enough to keep running. This ol girl is a beast, just never lets me down (hope I didnt just jinx myself) but over 18 years has never left me stranded. I may have to buy me another Ford while fixing this one up. A Tahoe just isnt my style. Anyway, basically this is to give a Kudos to Ford Trucks once again.

 

water pumps going out rapidly is a sign of a bad fan clutch.... just saying

 

I know it's been a few months since this thread has been touched on, but I am very interested in asking you, Dr. Bowtie, about my engine real quick: It's the 5.8. The truck has a fuel problem of some sort. I am no mechanic, but it seems to me that the fuel pump is going bad. Run the truck for any length of time (i.e. 7-10 minutes) and the truck starves of fuel, and stalls. I prime the pump about 3-5 times, and it starts back up and runs like it never had a problem. It hesitates on startup, like it has a lack of fuel, as well. That isn't my concern though. My concern is this: When I hit the gas quickly (instead of pressing it down slowly) the engine will hesitate like it hasn't got enough fuel pressure, and when I do this, if I keep the petal down like that for longer than a second, it makes this horrible knocking sound, like a heavy engine piece inside just fell into the oil pan, or at least smacked something inside. Is this a "piston slap?" Also, another thing it does: When you hold the gas down when the engine is NOT under a load, it will constantly tap, or knock. It doesn't sound like a ping really, but a persistent tapping that goes along with the engine. If the engine is accelerating or under any load at all, it won't do it. But say you're in park, and you hold the idle at around 1400-2400 (I'm guessing, no tach), it will knock lightly. Is this a rod bearing, or a main bearing? Or do you think all of this might be related to my lovely fuel problem? Any advice is a MAJOR help. This specific thread has been a big help to me, as I also have an exhaust leak. This I know for sure, because the exhaust is rusted out in multiple places. (The truck sat for 4 years, and I bought it this way.) Think it could be a sticky lifter, too, maybe? I am trying to figure this bugger out. It has only 118,000 miles, and it'd be a shame to have to rebuild this early in its mileage life, though if it must be done, it must be done.

EDIT: One more thing: It only really seems to do the tapping if it is warmed up. I haven't really noticed it cold. The exhaust leak goes away some warm, however, the "big knock" can be replicated no matter what the temperature.

 

I would say throw a fuel pressure gauge on it and see where the pressure is...

if it is low and you're running it you're doing more harm than good. when it is lower than normal it is running Lean... that will cause Detonation and that will hammer the bearings and create the sound you hear.

Basically when there is lack of fuel the injectors will "Spit" few instead of spray and that fuel will very violently ignite and it does at the wrong part of the cycle...when it does it is usually when the piston is coming up and not down so the hammer you hear is the rod bearings being beat to death...

The crank is trying to firce the piston Up and the ignition forces it down with greater force and you're hearing the metal collision taking place...

you're basically killing the engine every time you re-replicate the issue....

 

Wow... As much as I hate to hear that, I am very thankful that you just told me. I haven't been replicating it, though (to my good fortune!) and I have been keeping it parked. Actually, I kind of have to, as when I run it, as soon as it reaches operating temperature, it starts to bog down, and eventually die, and lately, it has not started after stalling until after a good 20-30 minutes, giving the engine time to cool down. Also, another development I have noticed, (I briefly mentioned it above) it is lately hard to start cold, and requires that I grind the starter for a bit to get it to start. Think it's the fuel pressure regulator? I only ask this because I recently changed my oil, like a couple weeks ago, and I already can smell fuel in it. There is fuel getting into the crankcase, and I have heard that the regulator can allow fuel into the crankcase from the vacuum. Reckon that the regulator's also bad? I don't have a fuel pressure gauge... Yet. 'Tis to come when I have the cash, along with two new fuel pumps (as the rear pump hasn't worked since I got the truck, and the poor front one seems to be on its way out.) My brother-in-law said that the working fuel pump could just need the "sock" cleaned, especially since when we changed the fuel filter, it had a quarter-sized chunk of crap in it that had hardened together. You could shake the filter, and it would rattle pretty bad! We bought the truck after it had sat for four years, and I drove it home, not knowing how long it sat, so a small amount of this crud went through the engine.

I am very sorry to say so much, especially on the OP's thread, (sorry, man!) but you have been quite helpful to him, and I am running out of cash quick on this truck! I am just a few parts shy of a new truck! Lol. Anyways, my two main questions: Do you think, based on the above information, that the pressure regulator is bad, and do you think that my pump could be bad, or just needs cleaned? Again, sorry if I hijacked the thread Mr. Fox, but I appreciate any and ALL information. I love this truck, and I want to have a champ for years and years to come! And again, thanks Mr. Bowtie for your very useful information, and Mr. Fox for not kicking me off your thread! Lol.

 

I'm betting the pump is bad...

the reason it wont start when hot is the pump is under load (fuel pressure) and it takes more amps for the pump to run and build pressure or even start the pump for that fact.

As the engine cools the pressure drops as it gets passed the regulator... they all drop a little during cooling... after 20-30 minutes enough fuel is bled off allowing the pump to run enough to get going and keep going.... pressure test gauge would verify it.

 

I was able to run a pressure test for it, finally. Priming the pump, not starting the truck, the gauge barely moved. (About 2 lbs.) Starting the truck brought it up to a whopping 26 lbs. Bad, considering the manual says 45-60 whilst running. When the engine was shut off however, the pressure remained the same at 26 lbs. It did not creep down, like I thought it would. So at least we know for sure the pump is bad, now. New one on the way in the next few days, I hope, for both tanks. Also going to clean the tanks.

I still have one question though: Do you think the pressure regulator could still be bad? What else could cause the fuel to get into the crankcase? I tested to see if there was any fuel being drawn into the vacuum line for the regulator, and there is not. It all seems to be functioning well. The fuel pressure regulator went out on a Bronco II I had once, and it caused the hard cold starts like what I am experiencing, and the fuel into the crankcase, like I'm having now.

Is there anything else that could cause the fuel to get into the crankcase, or do you think I could still have a bad regulator?

Thanks again for all the help! It's very appreciated!