Intermittent starting

[Gorbash]

Hey gents, I have a 1998 Explorer Sport that has recently begun having difficulty starting. Here are the symptoms: I can turn the key and the starter will turn the engine. Sometimes the engine will turn and turn, but not fire. Other times the engine will start and then die. Occasionally it will fire up like normal. It has yet to die while actually on the road.

So, here's the troubleshooting I've done. I got my wife to turn the key to the "on" position. Sometimes I can hear my fuel pump prime. This is when the car will start like normal. Other times I don't hear the fuel pump prime and then the car won't start. So, I feel like I've ruled out ignition and determined it is something to do with the fuel pump or the electrical to the fuel pump.

After reading some troubleshooting on here, I changed out the PCM Power Relay and the Fuel Pump Relay. I'm still having the same issue. I pressed down on the button on top of the fuel cutoff switch on the passenger side, but that didn't help. Next, I removed the switch to test continuity. I'm not sure this is a definitive way of testing the switch as the problem is intermittent, but here are the results. There are three spade terminals. If the button is pressed down, 1 and 2 have continuity, but 3 is out of the loop. If the button is up, 2 and 3 have continuity, but 1 is out of the loop. This would seem normal to me. I was thinking about making a jumper between the two terminals that have continuity when the button is pressed down to bypass the switch altogether.

So, if the switch isn't the issue, is there anything else I can test before changing out the fuel pump? If the fuel pump was bad, wouldn't it be more than just a starting issue...? Any suggestions or advice would be much appreciated!

 

[bobflood]

You have a classic fuel pump issue - confirmed when you correlated lack of priming with the hard starting. You have eliminated everything else - time to bite the bullet and change out the fuel pump. I just had mine done as I did not have time to DIY it; cost me about $370 including new fuel filter at my local shop. Good luck.

 

[2000StreetRod]

fuel pump relay

You can pull the fuel pump relay and insert a small flat blade screwdriver in the 35 contact. Connect the + terminal of a battery charger to the screwdriver shaft and the - terminal to the chassis. The fuel pump should run continuously. Your pump is 15 years old. It has served well. This link may help: Fuel pump replacement - 2000 Explorer Sport
The difference for your 1998 is that you have a return fuel system and mine is returnless.

 

[altab]

Took my 1998 Explorer XLT with similar problem to the dealer in December 2013.
Service rep gave me 2 options at that time:
1) Pay $120 for diagnostics which will likely not find the problem because it was so intermittent;
2) Next time it fails to start, try priming the fuel line by turning the ignition on (but short of starting) 3 to 4 times (if no ambient noise, should hear the fuel pump run, then stop after a second), then try starting. If it starts then it is a fuel bleed back issue at the fuel pump.
Opted for #2 and bingo, got it to start when I did have the problem again.
Took it to the dealer again and the service rep again gave me 2 options:
A) For $600+ replace the fuel pump. In the 98 Explorer XLT the pump is in the fuel tank so
the tank needs to be drained, purged, then removed ... reason for the added labor costs;
OR
B) Continue to do #2 above when encountering the starting issue.
... I opted for option B.