20 Most Recent 1990 Ford F250 - Page 4 Questions & Answers

Manual transmission?

check the fluid level in the reservoir. bleed out the brakes starting at the longest line first. There may be a leak in the booster that is allowing the brake fluid to be sucked through to the inlet manifold and that is why no visible leaks. heck for fluid running down the inside of the fire wall and under the mat.

look up under the dash where the brake peddle is hinged-there should be a rod that goes forward through the firewall to the master cylinder- check the pin that holds these together- Denny

Check your running fuel pump pressure. If (as I suspect) it's too low, first try changing your fuel filter. After changing the filter, recheck the running fuel pump pressure. If still low, check you fuel pump pressure regulator. If OK, you may need a new fuel pump.

Also probably would be a good idea to replace you air filter.

Good luck!

Is the cruise control in the multi switch ( turn signal, wiper, ect.?) This little switch performs way to many functions and could cause many different issues.

It is recommended that you tie a piece of string or wire to the old turn signal connector before you pull it out. Then tie on the wire to the new connector and pull it back through the column...If you have already pulled the old one out, you are just going to have to poke it in there someway. Try running a stiff wire through to get a string or wire pulled through it.

Many times actions like these are a result of O2 sensors recalibrating fuel mix or the transfer of operating duties from one computer to another.In some systems the initial run sequence is controlled by one system and then transferred to a second computer. If there is a bad connector or the second computer is bad, the vehicle will not continue running.

check linkages if ok the park paw may be dammaged replace trans

You have a leak somewhere. Check your brake lines for a wet spot. If you don't see any, pull the rear wheels and check the wheel cylinders. If you still can't find any leaks, it's likely the master cylinder going bad.

idle speed too low.should be 700 rpm.

try go to a michanic man

Have the fault codes read. Replace faulty items. Use onlygenuine items as replacement as non-genuine are not always compatible with the OEM fitted CPU units. This results in the fault codes not cancelling out.

what exactly is the trans doing/ not doing?

Well the brake light and turn signal circuits are on two different fuses, but they both go thru the turn signal switch.So I would start by checking for power in and out of the turn signal switch for each circuit.

electronic control module (the computer) If you found this helpful please leave good feed back

The transfer case is stuck in the low range. If manual shift try shifting from low to high several times to see if free up. If electronic, check all fuses and make sure you hear transfer case change range. Do this by shifting with key on engine off. If no change refer to qualified transmission mechanic.