Some of you may remember me mentioning how my truck was really slow and has bad MPG. I was driving, and noticed my fuel was getting low, so i switched tanks, and within a few molments, i noticed i had a lot more power, back to where i was before. So i switched back to my other tank and is slowed back down again. I tried to spin the tire off of a roll through stop sign and i couldnt spin one tire in 2nd in the rain! When i switched tanks, i spun it like i used to be able to on the exact same corner! Do the two tanks have separate filters? I can rule out bad gas, because both tanks are fueled from the same place at the same time i filled them both. I don't see how it could be the pumps, because they usually don't somewhat stop working, they either work or they don't. Any suggestions? Should i start by checking the fuel pressure on either tank? If the tanks have separate filters, maybe a filter is plugged up.



Primary rig is:
95' F-150 EB 300/6 5 spd with 4" Superlift, MSD, Ram Air, Gibson Exhaust, 32" BFG Muds
NEW PICS IN MY GALLERY!! :-)


Then theres:
88' F-250 Superduty 351 + c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 and a
3 spd column shifter baby. Top speed, 65mph, Go Baby Go!

The newest addition to the Ford family is a 99' Mustang GT 4.6L

 

Feels like a 25hp shot of nitrous at the flip of a switch!



Primary rig is:
95' F-150 EB 300/6 5 spd with 4" Superlift, MSD, Ram Air, Gibson Exhaust, 32" BFG Muds
NEW PICS IN MY GALLERY!! :-)


Then theres:
88' F-250 Superduty 351 + c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 and a
3 spd column shifter baby. Top speed, 65mph, Go Baby Go!

The newest addition to the Ford family is a 99' Mustang GT 4.6L

 

There is a fine mesh screen on the in tank pump suction.
That pump, having a direct current motor on it could possibly slow down for a number of reasons, ie, binding, dead or dirty comutator segments. How about putting a gage on the test fitting and testing your pressure with both pumps?

 

the fitting on the fuel rail, i'm not exactly sure how to check my fuel pressure. I have vague idea.



Primary rig is:
95' F-150 EB 300/6 5 spd with 4" Superlift, MSD, Ram Air, Gibson Exhaust, 32" BFG Muds
NEW PICS IN MY GALLERY!! :-)


Then theres:
88' F-250 Superduty 351 + c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 and a
3 spd column shifter baby. Top speed, 65mph, Go Baby Go!

The newest addition to the Ford family is a 99' Mustang GT 4.6L

 

had the exact problem with an 90 f250 351 4x4. on the rear tank it seemed to run ok but if you really pushed it it had no power. flip to the front tank and it took off like a bullet. changed the rear fuel pump and all is well. it could not supply enough pressure.

richard
88 f250 4x4 ex cab

 

The filter in the tank is called a strainer. Usually it does no become clogged. It is only meant to strain the larger particals not filter. So when the particles are strained they fall back into the tank. You check the fuel pressure by first finding a fuel pressure kit. Most auto repair shops have them and may possible allow you to use it in their driveway. You check it by first locating the scrader valve (looks like a tire valve) on the fuel rail. Hook up the pressure guage and turn the key on. I believe it should read around 15-20 lbs. Then start the rig and the reading should jump to about 30 PSI....

My guess is that it is the fuel pump. Either way to fix it you will have to drop the tank or lift the bed off. Then go from there. An entire new pump, strainer, and sending unit runs about 100.00 to 125.00. you can buy just the pump at usually around 75.00. I would say for the money just replace the entire set up and you shouldn't have any more worries.

One more suggestion is that it is the fuel selector valve. I myself have not troubleshooted one nor replaced one but I know they have caused some problems with fuel transfering between tanks. I don't know if it could cause your problem or not!

 

Thanks, i needed my mind to be refreshed on reading fuel pressures



Primary rig is:
95' F-150 EB 300/6 5 spd with 4" Superlift, MSD, Ram Air, Gibson Exhaust, 32" BFG Muds
NEW PICS IN MY GALLERY!! :-)


Then theres:
88' F-250 Superduty 351 + c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 and a
3 spd column shifter baby. Top speed, 65mph, Go Baby Go!

The newest addition to the Ford family is a 99' Mustang GT 4.6L