No fuel pressure '91 Ford Explorer

I am curious as to what you removed to check the timing chain. If you removed a valve cover or peaked inside a breather hole to see the rockers, there are other reasons for a no start.

The DOHC double cam engine has timing problems due to "cam phasers". You can find internet articles about this problem.

If unsure about the no start cause, try checking for fuel pressure. A simple reset of the Inertia switch fixes many no start problems by restoring power to the fuel pump.

The dual cam timing chain requires a lot of work to service. If the problem is the "cam phasers" , there are cheater tools which save considerable time and money to switch using shortcuts.

You also may have a bad fuel pump relay if you find the Inertia switch is not the problem and you can not hear the fuelpump run.

GM dont have inertia swith , they use double contact oil pressure switch to run fuel pump relay, no oil pressure no fuel pump

Could be. Did you replace the fuel filter too ?
Did you check the fuel pump relay and the inertia switch to see if the pump is getting voltage ?

If it is getting too much fuel you should be able to pull a vac hose such as the one to the PCV valve and make the engine speed up.
If it is too rich could be a fuel pressure regulator or injector problem.
Pull the pump relay and see if it starts then runs out of fuel.

No noise from fuel pump when you turn over the car .First thing get voltage at fuel pump relay checked, is there 12 volt to the relay.If no, then problem is again the relay.--------- To reconfirm the problem, try other test, that is remove the relay and by pass the relay terminals with a jumper wire .Then with 12 volt external battery give power to fuel pump connector and see, if the fuel pump starts, then its clear that fuel pump relay is faulty.----------- Also other problem can be fuel pump inertia switch.If the inertia switch is faulty then also fuel pump will not start.-------- The fuel pump relay on a 1995 Ford Explorer is in the power distribution
box, in the engine compartment, driver's side near the firewall.----------
The fuel pump inertia switch is in the right front passenger area
it is below the dash but above the carpet in the right hand corner.--------
Its a push button type inertia switch.
--------
Fuel Pump Activation
When ignition switch is turned to START position, PCM operates fuel pump relay to provide fuel for starting engine. PCM senses engine speed and shuts off fuel pump by opening ground circuit to fuel pump relay when engine stops or engine speed drops to less than 120 RPM. When ignition switch is in ON position, EEC power relay is energized (contacts closed). Power is provided to fuel pump relay and timer in PCM. Fuel pump receives power through fuel pump relay contacts.
Inertia Fuel Shutoff (IFS) Switch
All models use an electrical interrupt switch in fuel system. During a collision or vehicle rollover, electrical contacts within inertia switch open, shutting off fuel supply to electric fuel pump. Fuel supply is interrupted even when engine is running.
A reset button is located on switch assembly. If electrical circuit trips, vehicle will not restart until switch is reset. Fuel system should be inspected before resetting switch.
IFS switch is located under instrument panel, near right side of transmission hump. ----------- If the fuel pump relay, the inertia switch and fuel pump all checked ok, and fuel pump is working with direct 12 volt source to fuel pump.Then problem relates to computer.The computer (power control module, PCM) is faulty and has to be replaced.--------- This will help.Thanks.Helpmech.

The Inertia safety switch may have tripped on you. Depending on which Model of Ford you have, the Inertia switch is in different places. The most common place is at the top of the Drivers kick panel or the Passengers kick panel. Sometimes a hole is provided to allow a finger to pass through to press a button on top of the switch. On other Models, the kick panel must be removed. Yet a third place would be behind the glovebox around the computer.

When you turn the Key to Run, a short burst of the fuelpump will pressurize the system and then it waits until the engine starts, then continues running. You should hear the fuelpump run. When the button on the Inertia switch is pressed it makes a circuit.

Your truck should also have a Relay for the fuelpump and the Ignition. If the Inertia switch reset does not help, one of the Relays may be bad. Check whether you have spark at the plugs and go from there. If you have spark, you may not have fuel and need a fuelpump Relay.

I hope my solution is helpful to you.

Sounds fuel related, change the fuel filter if you haven't in the last 30K miles, if it is still doing it, have fuel pressure checked. If it still does the same thing it could be your fuel pump system. Check fuel pump relay, inertia switch (if applicable), fuses and lastly the actual fuel pump.

Did you check the fuel inertia switch in the passenger side kick panel ?

The fuel pump is powered :
the fuse to the fuel pump relay.
The fuel pump relay to the fuel inertia switch
The fuel inertia switch to the fuel pump itself.

At the fuel inertia switch in the kick panel, power from the relay is the Dark Green w/ Yellow stripe wire and the pink w/ black stripe wire is the power. from the fuel inertia switch to the fuel pump.

If you jumper the fuel pump relay, you should hear it run. If not pull the fuel pump relay, and check the pins in the relay socket, pin 30 should be the power from the fuse.



If you have power at pin #30, jumper the relay socket as shown with the red line above, and check the dark green w/ yellow stripe wire at the fuel inertia switch for power.
Press the button on the top of the fuel inertia switch, and check for power leaving the fuel inertia switch on the pink w/ black stripe wire.

This is tests good, check for power at the fuel pump, same pink w/ black stripe wire.
Fuel inertia switch info is in the owners manual, If you did not get an owners manual with your truck ( purchased used ), you can download one from Ford :
https://www.fleet.ford.com/maintenance/owners_manuals/default.asp

Will turn over but will not start

The fuel relay and inertia switch could be two different items. The inertia switch kills power to the pump. If there is a relay in between the inertia switch and the pump, then it would mean the inertia switch was tripped by slamming a door or an impact. Check your owners manual for the inertia switch. This website advertises online service manual reference.