I hope this is the right forum for this, feel free to move it if it isn't.

I have a 1995 F250 with factory upgrades which gave it a 3 ton suspension (F350)
351w/5.8 with electronic fuel injection.
It also has the tow package and off road package
It's super duty and 4 WD also.

I need help figuring this out. Several times I :ran out of gas in my driveway. I put in a couple gallons from the can, she fires right up. It started having problems starting when it was chilly to cold out, yet it will fire right up with a bump when warm. That seems weird to me.Nevertheless, I can take a hint. Tune up time. I was getting around 11 to 12 miles per gallon but when this started having starting problems my mileage went down to about 6 MPG. (Wow!)
my gas gauge don't work but the odometer does so I have just been making a ntation of how many gallons I put in and multiplied that by 10 (MPG) to be safe side and havent ha a problem until it started being hard to start and running out about 30 to 40 miles earlier than it should have. I calculated it and I was bouncing around 6 MPG.

So I imstalled a new cap & rotor, 8 new spark plugs, air filter and oil change. I did gap the plugs and they all came out looking better than I expected so I also ran a bottle of fuel line/injector cleaner through it and it's been fine since.

Note, while changing plugs I found a spark plug wire completely broken in half. I didn't have enough to buy new wire set but my neighbor gave me an extra old wire from his garage so I can make it run until next month's payday.

I thought, broken plug wire, yeah I bet that's my low mileage problem. And I've been trying to keep a little more rather than a low tank so I'd have less chance of running out . Today was chilly and raining, a nasty day. But i had to go out...it wouldn't start. Too cold I guess. I thought it can't be out of gas because it just had a decent tune up and I (should have had) another 30 miles to go before I ran out.

I put a two gallons in it from my can just to make sure, is it out of gas or not...It basically fired right up, so my mileage is not restored by what tune up I did give it. A broken plug wire being replaced should have made it run better, more mileage. I couldn't even hear it missing before, but it does sound better now. So what else could be causing this to run out ike that and have low mileage?

I am mechanically inclined but no top notch auto mechanic. So what am I missing here? Is it the cold? (I doubt it at this point)...or is there something else going on here?

Help! Lol.

 

Thread moved.

Try filling the tank up past 1/2 full.

You have to eliminate possible problems one at a time. Partial fills, possible slanted driveway--easy to suck air if you really don't know how much gas is in there.

 

Additional info:

Fuel filter is ok. Replaced a few years ago.
New starter about a month ago
I did replace both fuel tanks back in 2016 when I got this truck cuz they both leaked. Seemed to be ok, I got two new fuel pumps at the same time and replaced those too. I somehow buggered the rear fuel pump and it has not been working at all since. I'm running on one 18 gallon tank.

Question: Recommend me a brand of new spark plug wires for this truck. There's a huge price difference between cheap ones and more expensive ones...I *assume* more expensive means better wires? True or false?
I am handy with a multimeter...what should good Spark wires Ohm out at? And at around how many Ohms can I say whoa that wire was bad? I plan to Ohm the old ones, but it's raining today so maybe tomorrow.

 

I thought about that, my driveway is a wee bit slanted one way (goes thru to alley) so I tried parking facing the other way. It doesn't seem to matter which way, it still happens.

...easy to suck air how? I don't see any fuel leaks. So, that lines are good then, right?

 

If the tank is low on fuel, you can suck air.

Try Motorcraft plugs.

 

I did use Motorcraft plugs. (What good brand of wires to get?)

I don't understand why a less than 1/2 tank would cause it to leak air into it.
Could it suck air without leaking fuel?

 

Ok, payday was today so I got me some new wires and filled the tank up full.

I got the 8 spark plug wires on (pita) but have not replaced the coil wire yet...it's weird. It has some sort of adaptor connected to it and I guess I'm supposed to reuse it, but how does the qu8ck release thing come loose from the old wire? I can't tell and don't want to chance damaging it cuz then I'd have no ride to go buy a new connector...!

Any help?