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Does back pressure have anything to do with vacuum in a 1989 ford f150 4.9 litre efi engine

Truck started then died changed fuel filter and then checked fuil pump regulator and there was no vacuum off of tree on intake

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  • Cars & Trucks Master
  • 1,702 Answers

Hi, Sounds like you have an air intake leak. Most likely a bad gasket on the manifold to the engine block. Replace with new one. Good luck.

Posted on Oct 29, 2012


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Posted on Jan 02, 2017

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SOURCE: 1999 chevy silverado 5.7L 2wd

did you check the fuel pressure? there is a sharder valve on the fuel rail to do this. i know you have to have a certain amount of pressure in order for it to run.i think on fuel injection its around 60 to 70 psi.and on throtle body is around 30 to50.psi. i also know if you run your truck low on fuel alot it will burn up the pump gas is what keeps pump cool. also you said you found a pluged filter witch over time will burn up the pump. hope this helps.

Posted on Dec 20, 2008

  • 373 Answers

SOURCE: 1985 Ford F-150

if engine won't crack - dead battery
if engine cranks but won't start - no fuel or spark
fuel reservoir is the fuel tank.
a fuel filter can be inside a housing...

Posted on Feb 22, 2009

  • 125 Answers

SOURCE: olds alero 2.4 idle fuel pressure

most likely idle air control sensor or low engine coolant I know sounds funny but IAC uses coolant to regulate idle. Idle air control valve or throttle body positioning sensor.

Posted on Feb 26, 2009

  • 92 Answers

SOURCE: fuel pressure regulator had no vacuum line connected

another engineers wet dream. think of it this way . what is normally in the intake when the engine is running.. answer vacume, hence the regulator gets its vacume without a hose connected to it as its already in a full time vacume hose required . ps be carefull to seat the regulator and o rings securely into the housing befor you reattach the secureing metal clip.
good luck chris

Posted on Mar 23, 2009

  • 212 Answers

SOURCE: what is the fuel pressure spec for a 2004 tahoe

I would change the fuel pressure regulator first, if no change in pressure the fuel pump is on the way out.I have a 01 silverado 4.8 and my fuel pressure is between 55and60 psi.

Posted on Mar 03, 2010

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1 Answer

89 f150 5.0 efi dies when stoping and now wont start at all

Check fuel pressure. Your fuel pump could be at fault. Did you install your fuel filter correctly?

Apr 02, 2014 | 1989 Ford F 150

1 Answer

I have a 1989 international truck w/ 7.3 litre diesel. Same engine as in 1989 ford f-350 diesel. Trouble starting. I replaced glow plugs and glow plug controller / relay. Still problem starting do not want...

you answered your own question with # 1
the fuel leak is doing opposite when starting it is sucking
air . i had the same problem on mine,
it also let the fuel drain back to the tank that then
takes forever to reprime itself
hope this helps

Nov 14, 2010 | 1989 Ford F 350

1 Answer

How do I change the fuel filter

Fuel Filter REPLACEMENT It is recommended that the fuel filter be replaced periodically. The filter is of one-piece construction and cannot be cleaned, so it must be replaced. Carbureted Engines Fig. 1: View of the fuel filter used on carbureted engines 85551036.gif
  1. Remove the air cleaner.
  2. Loosen and remove the fuel tube from the filter.
  3. Unscrew the filter from the carburetor.
  4. Apply Loctite® or equivalent to the external threads of the new filter and screw the filter into the carburetor.
  5. Hand-start the tube nut into the fuel filter. While holding the filter with a wrench to prevent it from turning, tighten the fuel line tube nut.
  6. Start the engine and check for fuel leaks.
  7. Replace the air cleaner.
Fuel Injected Engines Fig. 2: Exploded view of the fuel filter mounting on fuel injected engines 85551037.gif
Fig. 3: Use a hand vacuum pump to relieve the fuel system pressure 85551038.gif Fig. 4: Exploded view of the fuel inertia cut-off switch and its location 85551039.gif
Fig. 5: Exploded view of the 5⁄16 in. hairpin clip type quick-disconnect coupling 85551040.gif
Fig. 6: Connecting and disconnecting the garter spring type quick-disconnect couplings 85551041.gif
Remove the fuel filter mounting bracket retaining nuts . . . 89681p04.jpg. . . then loosen the filter retaining clamp and slide the bracket assembly back . . . 89681p05.jpg. . . to provide better access to the push connect fittings (arrows) 89681p06.jpgWith a rag positioned to catch any spilled fuel, disengage the retainer clip and remove the line 89681p07.jpg NOTE: The inline reservoir type fuel filter should last the left of the vehicle under normal driving conditions. If the filter does need to be replaced, proceed as follows: CAUTION
If the fuel filter is being serviced with the rear of the vehicle higher than the front, or if the tank is pressurized, fuel leakage or siphoning from the tank fuel lines could occur. To prevent this condition, maintain the vehicle front end at or above the level of the rear of vehicle. Also, relieve tank pressure by loosening the fuel fill cap. The cap should be tightened after pressure is relieved.
  1. Shut the engine OFF. Depressurize the fuel system as follows: On the 2.3L EFI engine, a valve is located on the throttle body for this purpose. The valve can be located by removing the air cleaner. On the 2.9L EFI engine use the following steps:
    • Remove the gas cap.
    • Disconnect the vacuum hose from the pressure regulator located on the engine fuel rail.
    • Using a hand vacuum pump, apply approximately 25 in. Hg pressure to the pressure regulator.
    Fuel pressure will be released into the fuel tank through the fuel return hose. On most EFI engines the fuel pressure can be relieved as follows. Use special tool T80L-9974-B or equivalent attached to the pressure measuring port on the engine fuel rail. Direct the drain hose to a suitable container and depress the pressure relief button. An alternate method of relieving the fuel system pressure is to disconnect the electrical connector from the inertia switch and crank the engine for about 15–30 seconds until it runs out of fuel and dies.
  2. Raise and support the vehicle safely.
  3. Remove the push connect fittings at both ends of fuel filter. Install new retainer clips in each push connect fitting.
  4. Remove the filter from the bracket by loosening the filter retaining clamp enough to allow the filter to pass through. NOTE: The flow arrow direction should be positioned as installed in the bracket to ensure proper flow of fuel through the replacement filter.
  5. Install the filter in the bracket, ensuring proper direction of flow as noted by arrow. Tighten clamp to 15–25 inch lbs. (1.7–2.8 Nm).
  6. Install the push connect fittings at both ends of the filter.
  7. Lower the vehicle.
  8. Start the engine and check for leaks. Clean all dirt and/or grease from the fuel filter fittings. "Quick Connect'' fittings are used on models equipped with a pressurized fuel system. These fittings must be disconnected using the proper procedure or the fittings may be damaged. The fuel filter uses a "hairpin'' clip retainer. Spread the two hairpin clip legs about 1⁄8 in. (3mm) each to disengage it from the fitting, then pull the clip outward. Use finger pressure only; do not use any tools. Push the quick connect fittings onto the filter ends. Ford recommends that the retaining clips be replaced whenever removed. The fuel tubes used on these fuel systems are manufactured in 5⁄16 in. and 3⁄8 in. diameters. Each fuel tube takes a different size hairpin clip, so keep this in mind when purchasing new clips. A click will be heard when the hairpin clip snaps into its proper position. Pull on the lines with moderate pressure to ensure proper connection. Start the engine and check for fuel leaks. If the inertia switch (reset switch) was disconnected to relieve the fuel system pressure, cycle the ignition switch from the OFF to ON position several times to re-charge the fuel system before attempting to start the engine. prev.gif next.gif

Aug 13, 2010 | 1987 Ford Bronco II

1 Answer

1992 f250 5.8 litre engine back fire through airbox no fuel pressure changed out fuel pressure regulator no differant

Sounds like you may have a defective fuel pump causing a lean condition thus causing it to backfire.

Apr 28, 2010 | 1989 Ford F 250

2 Answers

92 Ford F150 4.9L. starts good, idles rough, dies at slow speeds

4.9 litre ?? you having a laugh its a 10ton truck engine not a pick up -global warming machine,remove the pump/sender unit and check the gauze filter also look inside tank for a something floating around ,i think the idles is not a related problem to the vehicle losing power but their is a possibility you could have a problem with the little vac operated thing on the fuel injector line that allows the fuel through only when the engine is running

Mar 15, 2010 | Ford F-150 Cars & Trucks

2 Answers

1989 truck stalls when hot.

Have you chg. fuel filter? If so, best to do a fuel pressure test, sometimes( not always) when the pump gets warmed up they can loose a little pressure and thats all it takes just a few # under recamended p.s.i and the truck quits running, you may hear the pump run but its not putting out the correct pressure until it cools down and it starts working again, but after a while quit all together.

May 27, 2009 | 1989 GMC K1500

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