OK, after reading many good responses on other posts I am turning to the members to try to help me with my unknown problem. I have a 93 F250 HD(over 8500GVW) 4x4 with a 5.8l and roughly 93k miles No rust clean truck.

The truck runs good, starts every time and is fine running out and about, but towing anything even 2500 pounds or going up a hill and the truck is completly inept. Also I get around 8mpg even when I am easy on it going around town. This is not my primary driver, I use it to tow a boat 10 miles to a boatlaunch and make hardware store runs.

This is what I have done
New Catalytic Converter and exhaust
New Fuel Filter
Performance Air Filter
New Plug Wires
Checked and cleaned points on distributor
Lucas Fuel Injector Cleaner
Engine Restore V8

Please help with any suggestions, I am stuck

Thanks

 

I'd like to know how you managed to do this as there are no points in your distributor.

You said you replaced the plug wires - did you really do that and not bother to replace the plugs, cap and rotor? Or is that what you meant by cleaning the points on the distributor? Did you just clean the contacts in the distributor cap and call it good?

What is the timing set to? Have you pulled the codes?

 

Points! Wow,Flash back! I'm sure he means cap & rotor. Your Error codes as mentioned, will point the way, And you need to see what your base timing is also, as mentioned. I'll guess possibly a pooched ETC sensor, but don't go buying stuff till you know for sure. Error code scans first! Maybe break down & buy/ install a new brass cap & rotor to go w/ those new wires.
A can of Seafoam too! http://www.f150forum.com/f33/how-sea...-1991-a-31505/

 

Check to see what gears came in the rear end. There is a tag on the pumpkin or you look up the axle code that is on the sticker near the driver's door latch. They should be either 3.55 or 4.10. If you have the 3.55's that could make towing a pain in the butt.

 

I meant cap and rotor, sorry I didn't replace them, just made sure there was nothing odd inside.

The truck does not smoke out the tailpipe, however when you really get on it going up a hill it leaks somewhere. I replaced the PCV valve when I did the Valve covers. I had a leak for awhile I could not find, I replaced the oil pan and seal thinking it was that, turned out to be a rotted dipstick tube that had a huge hole hiding behind where it tucks under the exhaust header. But I still have something going on and I dont know where the oil comes from and like I said it only happens when i really get on it, the oil drips down on the exhaust Y pipe which then makes it look like smoke, but as soon as I let off the Gas it stops within a second. However it does not leak in the garage or when I drive it nice and easy.

 

my father has a 97 250 HD with a 460. He had a problem with the truck warming up and would die everytime to it was started for 15 minutes. It turned out to be a sensor inside of the distruibutor. His truck gets 10 mpg empty or hauling a loaded down tool trailer.

 

had the same problem put in some bosch plugs and still had it finally put in some auto lite plugs and it fixed it.

I would say replace the cap and rotor

 

Never Bosch!! I prefer what's actually designed for your truck. Motorcraft. Engines under load more so, than average daily driving should run the stock Nic plated copper cores. This doesn't really sound like PIP sensor of TFI module as his spark is not dropping out. Read & investigate items mentioned in my previous post! Improper gap, maybe. Improper timing, fuel deivery & especially sensor, much more likely!

 

Question on fuel delivery statement, its an electronic fuel pump with new filter, does it have any settings are adjustments to try or would that mean that I need to replace the pump.

 

Non-adjustable if using the factory Fuel Pressure Regulator (FPR). If you have dual tanks you have 2 pumps. If the pressure is low on one pump and not the other, suspect the pump. If it is low on both, it's more than likely the FPR.

 

No settings or adjustments on that, unless someone at some point added an adjustable fuel regulator. I highly doubt it, because it sounds like a stock truck...

Speaking of fuel regulators, make sure yours isn't leaking. When they fail, they spurt fuel into the vacuum line and cause all sorts of problems. Pull the vacuum line off with the truck running, and see if it's spurting fuel out.

As opposed to throwing parts at it, I would suggest to go through the basics first:

-Fuel pressure check (should be 35-45 PSI)

-Vacuum gauge check

-Check timing (should be 10* BTDC)

-Pull plugs to check condition and gap (should be .044")

-Check for trouble codes (even if the light isn't on, there still may be some codes that may help) Instructions for getting codes: Ford Fuel Injection How To Run a Self-Test Three digit code definitions: Ford Fuel Injection 3 Digit Self-test Codes 111-171

These are in no particular order, just things I've thought of.

 

I will check the fuel pressure regulator as for the Engine coolant sensors would that just effect fuel economy or would it also affect power going uphill?

Thanks for all the responses keep them coming!!!!

 

Typically, just mpg issue (10mpg or less is it's trademark) however, it can "jump on the bandwagon" of other problems, making other unrelated drivability problems worse, keeping you out of ECU closed loop function & fuel trim.
Continuous over rich condition loading up the combustion chambers (ping & artificially reducing C/C c.i. displacement), contaminating the o2 sensor, & causing premature failure & a back pressure condition of the CAT. Other than that, what more could you ask out of one little bad sensor? Error code scans would tell you. Should be done at norm. op. temp.
It sure sounds like retarded base timing, but could be other things. What octane are you using?

 

I believe I got Code 33

then Codes
72 & 73

I wont be able to test fuel pressure for a few days. The truck never stalls and rarely ever even fluctuates at idle, It just has NO ***** going up hills or towing even 2500 pounds.

 

#33 EGR not closing properly/ Remove & clean EGR valve, check for proper function. Also at warm idle, remove Vac hose from EGR valve, should be no vac at hose at that time being supplied by the EGR Vac Regulator.
72 &73 probably op. error, not depressing accelerator during WOT part of test. I think "JCMS" covers this in his e/c/s info thread. http://www.f150forum.com/f10/how-ret...es-obdi-10907/