Hi, I have a1987 f 150 302 cu in with aod trans ,dual fuel tanks. 110k miles. I purchased it used and at first noticed it would shut off while driving sometimes being fine for 50 miles at other times it barely left the driveway. it would start back up usually after setting a couple of minutes, idle okay but bucking and stumbling , sometimes doing this for 10 mins. I replaced the ign module with a wells unit purchased at autozone. it seemed okay for awhile...... then started doing it again....Now a new problem.... the pumps will not energize after turning the key to the"on" position ( won't start), i repl the fuel pump relay and still no buzzing, no fuel pressure at the shrader valve..... the engine will run if you squirt fuel into throttle body.........HELP!
An expert who has achieved level 3 by getting 1000 points
An expert that got 10 achievements.
An expert that got 5 achievements.
An expert whose answer got voted for 100 times.
Re: no fuel pressure/shutting off
Try putting a new fuel pump in it or check the fuel tank switching unit it might have failed. (switch or unit under truck).I would go under truck and try to isolate one tank both electricaly and mechanicaly the see how it runs.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If the fuel pump(s) run while the pressure is falling, replace the fuel pressure regulator and (although I'm sure you've already done this), replace the fuel filter. If the fuel pumps appear to be turning off by themselves, replace the inertia (fuel cutoff) switch.
you probable skipped you're 90.000 major service point 30.000 60.000 90.000 platinum plugs are gone at 100.000 , ready...get you're wallet out.. trans filter service. Flush change all fluids ..brake coolant etc.... rear brakes are done unless replaced..check all brakes..plug wires drive axle fluid. Thermostat... cheep part very impotant. timing belt if it has one .. if it brakes it could smash valves or shut you down..when you do timing belt better do water pump it is usauly driven by timing belt and check all belt drive pullys
You'll have to do some investigating to find out. First, is it a lack of spark to the plugs, or fuel to the injectors ? Then, is it something getting hot like a relay or the coil, or something like a build up of pressure in the gas tank.
Fuel Filter. Sorry I have not worked on this exact model but usaly mounted near fuel tank or on frame rail. Purchase a new filter and check fuel lines. May need tubing wrenches. On rare occation a car has bottomed out and crushed the fuel line. There should be a JIC fitting on the fuel rails as there is a fuel regulator and return line to the tank. I use my A/C gauges with a 3/8 R12/R22 fitting to check fuel pressure, could be 44 psi, but may vary with engine. If fuel pressure is to low the Fuel pressure regulator needs replaced.
nap Z engine is a venerable work horse using dual ignition design but wont get much better mileage than you are experiencing now ... try larger tires..more air pressure. premium fuel every 10th tank full (unocal 76 , 91 octane).....free flowing air filter (K&N ) hotter spark plugs ..indexed prefereably...timing advanced slightly..tailgate down or install topper or tonneau bed cover... check jet chips or other co. for performance computer upgrade...good luck