Thread: fuel pressure

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can you please help me
1989 ford 150, 4.9 EFI new pump in the tank, new high pressure pump,new fuel filter, and fuel pressure reg. truck has good fuel pressure 50lbs, truck runs for 10 min. stalls.....pressure dopes just before it stalls, recheck feul pressure 8lbs wait 20 min truck restarts for 10 min or so. whats going on the pump in the tank getting hot????????????????????????

please can you lead me in the right direction

Originally posted by mike street
can you please help me
1998 ford 150, 4.9 EFI new pump in the tank, new high pressure pump,new fuel filter, and fuel pressure reg. truck has good fuel pressure 50lbs, truck runs for 10 min. stalls.....pressure dopes just before it stalls, recheck feul pressure 8lbs wait 20 min truck restarts for 10 min or so. whats going on the pump in the tank getting hot????????????????????????

please can you lead me in the right direction

98 Ford wasn't available with the 4.9, however, there was a change in the in-tank harness that could be causing your problem due to low voltage (heat). Here it is;

ISSUE:
A revision in the type of in-line sender wire connection inside the fuel tank on the fuel sender has been made.

ACTION:
When servicing a fuel pump/sender, refer to the following Service Procedure to correctly connect the wires to the fuel pump/sender.

SERVICE PROCEDURE
Due to various changes, the 1998 model year vehicles' fuel sending units have two different types of in-line sender wire connectors. One is a hardshell connector and the other is a shrink wrap cover in place of a hardshell connector.

For removal and installation of the fuel sender, refer to the appropriate Workshop Manual, Section 310-01.

1. Verify the type of in-line sender connector, hardshell or shrink wrap.

2. If it is the hardshell connector, pull back on the connector to disconnect.

3. If it is the shrink wrap type, cut around the connection with an precision cutting knife, then disconnect the in-line connector by depressing the tab.

4. Remove the sender assembly from the bracket.

5. Install shrink wrap over the sender wires, then put the connectors together.

6. Slide shrink wrap over the mated connection and heat the shrink wrap with a heat gun.

WARNING : ALL HEAT SHRINKING MUST BE DONE AWAY FROM THE FUEL TANK AREA. A HEAT GUN MUST BE USED TO SHRINK THE WRAP.

7. Reinstall the fuel sender following the procedure outlined in the appropriate Workshop Manual, Section 310-01.

Good ol' copy and paste.

Originally posted by mike street
can you please help me
1998 ford 150, 4.9 EFI new pump in the tank, new high pressure pump,new fuel filter, and fuel pressure reg. truck has good fuel pressure 50lbs, truck runs for 10 min. stalls.....pressure dopes just before it stalls, recheck feul pressure 8lbs wait 20 min truck restarts for 10 min or so. whats going on the pump in the tank getting hot????????????????????????

please can you lead me in the right direction

dont you have 2 fuel pumps, may have put the wrong one in. one a push and one a pull.

yes i have 2

The pump on the frame is the high pressure pump. The one's in the tanks are merely lift pumps. Also a recall on the switching valve that could be causing your problem.

Free repair possibly.

VANS AND LIGHT TRUCKS WITH DUAL FUEL TANKS PRODUCED IN THE FOLLOWING PERIODS: F150, F250, AND F350 LIGHT TRUCKS BUILT BETWEEN FEBRUARY 28, 1989 AND JULY, 1989; ECONOLINE BUILT BETWEEN FEBRUARY 28, 1989 AND FEBRUARY 11, 1991.

NOTE: FORD HAS AGREED TO RECALL THESE VEHICLES BUT PARTS ARE NOT YET AVAILABLE.PARTS WILL BE AVAILABLE IN DECEMBER 1991. YOU WILL RECEIVE A LETTER FROM FORD ADVISING YOU WHEN TO SCHEDULE AN APPOINTMENT WITH YOUR DEALER TO HAVE THE RECALL WORK PERFORMED. IN THE MEAN TIME, YOU CAN TAKE THE FOLLOWING PRECAUTIONS:FILL EACH TANK TO ONLY 1/3 FULL. IF YOUR VEHICLE LEAKS FUEL OR IF YOU SMELL FUEL, STOP USING THE VEHICLE AND CALL FORD AT (313) 446-4654 AND ADVISE THEM OF YOUR PROBLEM. REFER TO FORD SAFETY RECALL NUMBER 91S39. AN OPERATOR WILL TAKE YOUR NAME AND TELEPHONE NUMBER. A FORD REPRESENTATIVE WILL CALL YOU BACK.

rear tank don`t work

switching valve , can cause ful pressur drop, whats funny that it runs for 10 min then stalls

Originally posted by mike street
yes i have 2

im not postive mike but i thank if the pusher dont work then the motor wont run either like it should. run a hose from the fuel pump on the chassis into the tank and see if it will run that way. bypassing the switch.

The frame pump is a pusher only. Construction is of a type that produces no vacuum (pulling ability) until it is fed fuel. The lift pump can , by itself, produce 5-10 psi. Sounds like the lift pump is working and the pressure pump is giving up the ghost.

Originally posted by mike street
switching valve , can cause ful pressur drop, whats funny that it runs for 10 min then stalls

which pump did you replace the one on the chassis or in the tank?

^ NO START - 4.9L, 5.0L, 5.8L, 7.5L - FROM CORRODED OR LOOSE WIRE SPLICE IN 12A581 WIRING ASSEMBLY

^ WIRING - 12A581 WIRING ASSEMBLY - CORRODED OR LOOSE WIRE SPLICE RESULTING IN POSSIBLE NO START

LIGHT TRUCK:
1987-90 BRONCO, F-150-350 SERIES

ISSUE:
A no start condition may be caused by loose or corroded three-way wire splice in the # 37 circuit of the 12A581 wiring assembly.

ACTION:
Repair the corroded or loose wire splice by using the following service procedure.

1. Disconnect the negative battery cable from the battery.








2. Locate the fuel pump relay, Figure 1.

3. Trace the # 37 circuit wire (yellow) from the fuel pump relay into the 12A581 wire harness.

4. Carefully cut away enough harness wrap to expose the splice (about 4 or 5 inches).

5. Examine the splice. If loose or corroded, repair as follows:

a. Cut out the bad section.

b. Reconnect the wires together.

c. Solder the wires with resin core electrical solder.


6. Use heat shrink tubing (WT5625) to insulate the splice. Tape (EOAZ-19628-A) and put back into the harness.

7. Reconnect the negative battery cable.

8. Test the vehicle for proper operation.

mike street thats some good info. sparkey is giving you there, if thats the problem. if my fuel pump stopped working i woudl know if there was 10 to 12 volts at the pump or not when it cut off. if there was no vaolage there then the info starkey gave you would be nice to know, but if youve got 12 volts it dont mean much. before you go fixing a problem you might not have, id check to see if i had 12 volts at the pump after the motor stopped running. ford has had that problem way back when, but you check it by not having any voltage at the pump.

took pump out of tank, ha ha .....truck runs fine when the pump is out of the tank......what a night mare...going to buy aft and front tanks, 2 sending units and sell the truck thanks guys