Hey y'all-

Bear with me; I write long but thorough posts.
I just purchased a '94 F150 work truck for my (very small) company. I got it home and, after driving it for a few days, discovered it has/has developed a few more problems than I did not realize at purchase time.

Here are its stats: It's in really good shape in and out. I6 300/4.9L, 5 speed, 3.55 axle (?), reg cab/long bed 2WD, base model with crank windows and rubber floors, 179,000 miles. Runs good, shifts good.

1. Dual Gas Tanks- I know a lot has been written on this. Previous owner said they both worked, but he just used front. I checked both when I purchased. After getting it home and filling both tanks up, was driving with rear tank running and front full. At 1/4 tank, rear began to pump fuel into front tank (I'm guessing), causing it to start overflowing from the front tank gas cap. I switched to front tank (this happened this evening. I have only had it long enough to run a tank of gas through the rear tank).

2. Crappy Mileage- I think there is something up with this truck, because the mileage is really bad. 3/4 of rear tank barely got me 60 miles in town with no load (before I switched to front tank; see above #1). I ran the back tank from full to empty when I first got it and got simular mileage on the interstate @ 60 mph (which will be #3 quesiton). I know to replace O2 sensors, clean MAF, Seafoam in gas tanks, suck some seafoam into intake from port on brake booster, plugs, rotor cap, etc. Throws no codes.

3. REAL Slow Top Speed????- I have owned/own trucks both gas & diesel with granny gears/4x4/low geared etc transmissions. They top out at non-interstate friendly speeds, (except my 2006 Chebby 2500HD which has a 6 speed manual). This Ford was built w/ the 5 speed&OD mazda transmission and isn't that low geared, but it really doesn't seem to want to run more than 55-60 on the interstate w/out sounding likes its really revving too high ( I know 4K+ rpms are bad for this 4.9L). The truck doesn't have a tach, but it really decelerates very quickly when you let off the gas @ 60 mph (PS- stock size tires). In comparison, I recently owned a 2008 F150 6 cly/5 speed that seemed to be geared similarly in 1st, but ran in OD on the interstate as you would expect. Can anyone give me some input if this is normal? For reference, on flat ground in clear traffic, I shift into OD between 42-50 mph.

4. Wiper Motor Dying- When I purchased the truck @ end of last week, the wipers worked fine at all speeds, but after driving it here in AL in the rain for 2 days, the wipers aren't actuating in the first slow setting or two, and the high setting causes it to jerkily drag across the windshield, and causes an electrical clicking sound from underneath the dash. Is the wiper motor just dying?

I appreciate your thoughts, input, and advice. If I need to be directed to an existing post, please let me know and my apologies in advance.

 

Hi,I have a '96 F150 Reg cab Long bed I6L,300ci 5 speed stick,2wd with 273 rear gears.My truck does the same gas tank trick as yours,right after I got it(7yrs ago)filled both tanks,started driving on rear and overflowed front.Each tank has it's own pump and has a valve in it that closes the return line when that pump is not being used.My front pump is the culprit.I have just gotten used to running the front tank first then the rear,otherwise it's a new pump in the FRONT.Your fuel system returns the unused gas to the tank,hence the return line.Mine runs 1750rpm at 70mph,sounds like your rear gears may be a lot lower geared than you think,it is common to run reel low gears when running big 33"and larger tires to make up for the loss in power,maybe someone did that to yours.Your rpms are out of sight.The low gearing would account for the bad milage also.You would benefit more from the 300 IL Engine forum,great helpful people on there.Hope I helped you a little.PS Welcome to FTE!

 

All I can say is it does sound like the wiper motor dying (mine did it in the rain up in the rocky's) same thing from the sounds you describe. Definitly run front then back, to stop that issue, thats what i did no more leaking fuel. as to top speed issue, is it 4X4? possibly, transfer case locked up, but not likely. But, if it is 4x4 then the previous owner may have geared the hell out of it. like the one above me said, your mileage will be beyond terrible if your geared so low. and a little info, the Inline 6 didnt get almost any better mileage than the 5.0 maybe one or 2 better, but, still. not to great for a 6.

 

300 Buster-

Thanks for the helpful reply. How does one ask the Moderator to move a thread over to that 300IL forum??
We will just start running the front tank dry first. the truck is a 2wd w/ stock size 235/75/15s on it, so I don't believe it was regeared. Personally, I guess I don't think of 3.55's being "steep gearing", but its definitely a lot less highway-friendly than your 2.73's. I was kinda wondering about doing a zf-5 speed conversion to it before the summer, as I would really like to use the truck to pull a trailer regularly (from what I read, a non-diesel 2wd zf-5 will bolt up to the 300, as it was offered in that combo in 3/4 ton and maybe 1 ton applications). Depending on folks thoughts about that conversion, buying a junkyard axle with a much taller rear gear would help compensate.

adam.hilberath- I should have specified 2wd. The truck seems to be completely stock anyway, so I just was a little surprised at how slow it ran on the interstate. And I know the mileage ain't great, but I was getting roughly 6 MPG around town, while people with similar trucks seem to be getting more like 12. Just thought something's up with it. Wiper motor should be an easy fix.

Thanks again.

 

My truck(described earlier)will usually get about 19-20 on the highway,as for top speed,I've never tried beyond 95,but I can tell you that I've down shifted to 3rd for a fast pass at 70.It sure sounds like very low gear ratio to me,the milage,the high rpm and quick speed reduction when you let off,and possibly the low top speed all sound like very low gears.If you want a rough idea,jack the back wheels up and turn the drive shaft,count the turns of the shaft per 1 rotation of the wheel,if it's more than 3 1/2 it's beyond 3.55.Be sure and check the zf swap out,I was thinking about it when my m5od locked up at 70 on the freeway(wild ride)and only left 1st gear.It looked like you may need a different drive shaft.Good luck with everything.

 

first thing i would do is a tune up and check the fuel pressure could be just a bad pressure regulator . then check the cats and see if there clogged.