Got an 02 Explorer Sport. Went to start it and no start because of no fuel. Checked fuse and relay - good. Checked inertia switch - good. Dropped tank (lots of work!)pump works. Connector at pump clean, not corroded.Zero fuel pressure, found no leaks, ran fine before it’s last “shut ooff”. Some kind of short… but where to check next. Clean truck, just turned 60k. Ideas welcome!!
You’re saying the fuel pump works, yet you have ‘zero’ fuel pressure.
At what point in the fuel system do you not have pressure?
Does the fuel pump prime when the ignition key is turned to the RUN position?
When you checked the fuse and relay, how did you check them?
Did you remove them and replace them with ones you KNEW worked? You can’t always tell by just looking at them.
The fuel pump relay is powered by the PCM relay and both relays are controlled by the PCM, which provides grounds to kick both relays. There are several fuses involved and one fusible link. The ignition module provides a pulse to the PCM which then tells the PCM to ground the fuel pump relay.
About all I can suggest is make sure that ALL fuses and fusible links are good first. The vehicle can also be scanned for codes; some of which may provide an answer to the fuel pump circuitry.
After that, you’re going to need a wiring schematic and the ability to trace it out or a flow chart to aid in the diagnosis.
At this point I hate to get into a wire by wire analysis due to the length of the post but if you get stuck we can try and wade through what we have on the AZ site. Some of my manuals go to '02 but do not cover the Explorer. (Should be similar though). It’s not really complicated but does require a methodical approach.
By “fuel pump works” do you mean you can hear it running? If so, it may still be defective.
If there is no fuel OUT, there may be no fuel IN. You may have wired the pump to run backwards. The Fuel level may be too low. The filter sock, on the fuel pump, may be clogged. If pressure is taken AFTER an external fuel filter, the fuel filter may be clogged.
For more tips on troubleshooting fuel systems, go to: www.carterfueldelivery.com/fuelpumps
Think you guys are living in the past. An 02 should have a returnless fuel system and an electronic module that varies the speed of the pump. Could be that module is bad. Go to message board of www.explorer4x4.com where people know Explorers.
I fail to see how the specifics of the design of the fuel system make any material difference in the responses. There is no evidence that heywood is using an electrical multimeter, or, a wiring schematic. Using those tools is up to heywood. It’s his observation that the “pump runs; but, there’s no [fuel] pressure”. We can’t perform the troubleshooting FOR someone. All we can do is, “lead the horse to water”.
He leads one to think the pump was tested and working when the tank was removed from the vehicle. Checking the fuse and relay indicates the pump didn’t get power in the vehicle. That leads one to think it might be the electronic module that controls the pump speed. This module did nit exist in earlier Explorers and no one else has mentioned it.
It doesn’t matter which system this Explorer uses. The pump runs or it doesn’t. It has pressure or it doesn’t.
There is a production cutoff of 03/2002, there is one style of fuel pump before this date and a different style after this date. Maybe heywood could provide the production date of this vehicle, then we would know what style fuel pump he has.
I do have access to the diagnostics for both systems and frankly it isn’t for the DIYer. It is rather complicated, with many components to check.
Here’s some explanations that should be in the repair manual that heywood could be using: “The fuel pump is enabled during crank, or running mode, by the PCM (engine computer) with a signal from the crankshaft position (ckp) sensor. The PCM transmits a duty cycle to the Fuel Pump Driver Module (FPDM). The FPDM modulates the voltage to the fuel pump to achieve the proper fuel pressure. The fuel pressure regulator is inside the fuel pump module.” Does this help? Without a signal from the CKP sensor, will the PCM allow any fuel pressure build up? The repair manual should answer this question.