the 89 sat for 2 years before I bought it. the frame mount pressure pumps been replaced as has the thermostat. but I can't get it to run right I suspect the intank sending units what do ya'll think???

 

if the gas is 2 years old, that could be your problem right there.
if it's fresh gas, then check fuel pressure and pull codes.

 

no check engine light, and there's no old 2 year old gas, I've got fresh gas in it. the fuel pressure might be something to check. but it does have a new frame mount high pressure fuel pump, so the only thing I can see causing a fuel pressure issue would be the fuel pressure regulator???

 

New does not mean good. Verify before emptying your wallet again.

 

ok, So what I've more or less decided is to replace the injectors AND the intank fuel sending units and possibly the FPR as preventative maintenance. even if they aren't bad YET it does have 170,000 on it more or less so replacing them now will save me trouble later

 

Think I'd run the codes & put a pressure gauge on it first.

Shotgun is a great hunting tool & home defense weapon, but lousy diagnostic tool.

But if you got the cash & time...

 

x2 ... if you are gonna own and work on a fuel injected vehicle, you really should own, or at least have access to, a fuel pressure gauge, and codes are easy to pull. there can stll be codes stored, even without a check engine light staying on.

 

Oh I know how to pull the codes at one point I had an equus 3145 I believe it was, but it mysteriously disappeared during a move

 

Ok, So I finally got over to work on the truck kinda under the gun to get it running now. anyway I changed the fuel filter BOOM there's my fuel starvation issue it was almost completely clogged. I pulled the inlet hose and it shot fuel under so much pressure it was a mist E.G. the max mist setting on a spray bottle and the crap that poured out was a rust/reddish color and thick, So my next question for those of you on here is How likely am I to be ok with just the filter or is there likely collateral damage??? and if so what should I be suspicious of???

 

If this was mine i'd be happy that i found the problem & take it out on the higway to blow the cob webs out of iit. Or you can keep fixing it til it's broke.

 

Filters are cheap. Run it for a day or two & change. If its still has a large amount of rust in the one you just replaced, your tank is probably rusted pretty bad.

 

These guys are right, Shotgun approaches are not the best way at all. Even on trucks like my '87 that has been idle since '07 and was abandoned since then. I could just shotgun blast it and replace anything I think could be bad as "Preventative Maintenence" so I could be sure....I'd have a new truck at the point. Never assume a part is bad without checking it first and verifying it. Technicians do it all the time with customer vehicles. Esp. warranty cars.

And I also have an 89 model with the straight 6. It has right at 203K miles. When I parked it in 2012, the on rail pump had been there since before 2006 and only thing "maintenance" that was done on this poor truck before I got it was tires and oil change. Still ran great. Been in the family since '92. And you could bet that every 5 years the on rail pump would fail.
If the fuel is as bad as you say, Drop the tank and remove the intank pump and inspect the tank. My '87 had brown junk fuel coming out...Dropped tanks and the whole tank is rusted with "crumbs" and sending units are destroyed aswell. Or, Leave it and run the **** out of it thinking the inline filters will save you but either way if that pump pulls to much debris in and jambs up you'll be dropping it either way. And it'll quit at the worst time. Socks don't catch everything if this one is still intact or there at all. Luckily its the low pressure pump...

And not all filters are made to actually work. I've had wix filter pour black fuel on the "clean" side and clean on the "dirty" side before. And people usually rave wix.

 

eh, me and the wife are on a fixed income I abandoned that approach a long time ago. I started assessing the truck. I suspected the filter based solely on how rapidly the truck went down, now the next question is how difficult is it to drop a tank on one of these things and what tools are needed???

 

How difficult depends on how full it is. If its close to empty its not bad. Some people pull the bed off to access it. While it is "easier" to work on per se but you have to disconect tail light wire harness, fuel filler hose, anything in the bed or mounted on it, etc... Its easier because you're not on your back holding anything up.

What I do is drop it and if its full or has any fuel in it I get a 2X8 or something close and put it between the tank and floor jack. Once its there, I loosen the two strap bolts. I don't remember the exact socket sizes off hand but you'll need a combination wrench and a deep well socket and ratchet. 3/8" drive will work.
If you have bad rust/corrosion/etc... A can of PB-Blaster is you're best friend. Soak the strap nuts real good and "attempt" to spray the bolts on top.
Once they've soaked for a while, Start trying to loosen them. You can do one at a time or both at a time. Your choice. Once they're loose, The tank may be a "nervous" so hold on. Gently lower the tank and slowly. Once you can get to the wire connector and tubing stop there immediately. You dont have much slack to work with. On my '89 I had to pull the filler neck from the bed first then lower it but on my '87 I could leave it attached and loosen a hose clamp on the neck to separate the two. It depends on how it is built but I would just pull the neck from the bed to be safe.
After the neck, Next comes lines and electrical. There is a connector on top you have to pull off.
Then, to get the lines off they should be held on with two small hose clamps. Mark which one is IN and which is OUT. Masking tape works good for this. Careful, Lines could still be under pressure. On a 300-6 there is a schrader valve I believe on the injector rail for this. You don't want to get them lines mixed up...Once the neck, wires, and fuel lines are off, Its totally free from the truck.
You could let the jack down all the way now and kind of "man handle" it off or put blocks under and do whatever you need to there.

Now, while this reads likes its easy, Its not. I'm short so I can sit up under my '87 because the rear sits high, My '89 is a little lower so I'm hunched over.
But holding the tank so it doesn't fall off and make it a real bad day adds to the fun. I'm sure someone else can chime in with more detailed explanation and exact tool sizes or maybe a better way.
I just know this is how I've always done it on my Fords and even my Silverado and never had a problem. But more fuel = more work = longer and harder to do.

PS: Depending on how bad the tank is or how the pump assembly looks, If you can comfortably afford it, I'd replace the pump since you're in there. I know the rail pump has a 5 year give or take lifespan and its alot easier to change than this one is so I'd do it. Ford fuel pumps are like Injector pumps for an idi. They're only good for so long then they die. And usually, the harder a Ford part is to change, The more expensive and difficult it is to change I've noticed.

 

If the pump runs, by the way you can disconnect the output line (put it in a fuel can) & jump the diagnostic connector under the hood to "drain" the tank.