Starting Issue

[Axlehead]

Hello, I am a long time lurker who decided it's time to join the forums. I purchased a 99 Explorer XLT a few months back. Since then I have been fixing some of the obvious issues, but one still kind of confuses me. I've owned many Fords and this is the first time I have experienced this starting issue. I'm sure I'll be asking a few questions here and there as I have a few different things I need to fix. This issue is high on my priority list though.

Basically there are occasions when I turn the key the engine never starts. It just turns over. However if I wait a few seconds after the first key turn it will usually fire right up. The main suggestions I've been given is to replace the relays for the Fuel Pump, Ignition, and PCM. I've considered this since it would obviously be the easiest fix, but I feel like if any of the relays were bad that it wouldn't work at all. I was just looking for any opinions of simple things to check before I assume the worst and get the pump replaced. Also the plugs and wires have been replaced recently and didn't improve the issue. Thanks!

 

[koda2000]

You need to start by checking your fuel pressure. A '99 should have around 65 PSI at the fuel rail.

I've had to replace all the fuel pumps on our 6 Explorers/Mountaineers at between 175,000-200,000 miles, so that seems to be their life expectancy. In almost all cases the first sign of impending fuel pump failure was intermittent starting, where multiple turns of the ignition key from OFF to ON would eventually produce a start that would work until the next day. Almost all intermittent starting would begin in colder outdoor temps.

There are other things that can produce similar intermittent starting, but they are easily tested (swapping the fuel pump relay, checking the relay's electrical connections for tightness and corrosion, checking the connection at the inertia switch) but if you've got anywhere around 200,000 miles, odds are pretty good your fuel pump is worn out.

I replaced just the fuel pumps in my Ex's as my fuel gauges were working fine. I use Bosch replacement pumps which come with everything needed, including new submersible fuel hose, hose clamps and jumper wire to convert from the thin to thick pump terminals. The only other things you'll need to buy is a new fuel filter and strainer sock. Total eBay cost runs around $80 or less. I've had zero problems with any of the Bosch fuel pumps since installation.

BTW, It's highly unlikely your issue is the PCM as your issue is intermittent starting.

 

[Axlehead]

I appreciate the information. The vehicle has under 115,000 miles so I'm hoping it isn't the pump. I will try swapping the relay first then move onto the fuel pressure test. Thanks!

 

[lobo411]

One thing you can do: the next few times you turn the key to "run," just before turning it all the way to "ignition," wait a second and listen for the fuel pump whine. It should whine for a second or two. If it doesn't, then you know that you have a problem somewhere in the fuel pump system.