Intermittent no start, '96 5.0

[V8Pete]

My '96 5.0 will occasionally crank, but not fire - fuel pump not activated. If I try a few times, it'll start, and no further problems. As it never quits once it's running, I'm guessing it's the ignition switch (no juice to the fuel pump in Start), but I'm just guessing. Can someone enlighten me?

 

[BrooklynBay]

Check the fuel pump relay.

 

[V8Pete]

Check the fuel pump relay.

As in, did it kick off? I did, and it didn't

 

[BrooklynBay]

So there is no power going to the relay? Did you check the inertia switch, and the PCM relay? Do you see a check engine light on your dashboard when you turn the key to the accessory position? Check the ground wire near the battery too. If the computer has no power, the fuel pump won't have power either.

 

[V8Pete]

Sorry, I thought you wanted to know if I had to reset the relay. No. I didn't check the other two things. No CEL. I think if it was any of the items you mentioned, it wouldn't start at all, or could stall once it's started, right?

 

[performancenut]

Possibly a cam position sensor. I seem to recall that the fuel pump signal to the PCM is generated via this route.

 

[wcraycroft]

My 95 Explorer would occasionally crank but not start. Occurred ONLY when engine was warm -- never on the first start of the day. After waiting anywhere from a few minutes to 2 hours, the engine would then start normally. Happened between once every few months and 2 - 3 times a week, and VERY intermittently. When I drove it to work and then it sat for several hours, it would always start. When I monitored the EEC-IV codes, it would always start, of course. Finally took it to a dealer I trust and left it for 2 days so they could try to repeat the problem. They finally got it to happen and determined that there was no fuel pump pressure when the engine was in this state. They replaced both the Fuel Pump Relay and the EEC Power Relay. After these replacements, they could no longer duplicate the problem. This was almost 4 weeks ago, and I have not experienced the problem. It could just be the odds, or the relays may have been intermittent. Since it is a cheap repair you can easily do yourself, replacing these two relays would be my recommendation as a starting point.

 

[V8Pete]

My 95 Explorer would occasionally crank but not start. Occurred ONLY when engine was warm -- never on the first start of the day. After waiting anywhere from a few minutes to 2 hours, the engine would then start normally. Happened between once every few months and 2 - 3 times a week, and VERY intermittently. When I drove it to work and then it sat for several hours, it would always start. When I monitored the EEC-IV codes, it would always start, of course. Finally took it to a dealer I trust and left it for 2 days so they could try to repeat the problem. They finally got it to happen and determined that there was no fuel pump pressure when the engine was in this state. They replaced both the Fuel Pump Relay and the EEC Power Relay. After these replacements, they could no longer duplicate the problem. This was almost 4 weeks ago, and I have not experienced the problem. It could just be the odds, or the relays may have been intermittent. Since it is a cheap repair you can easily do yourself, replacing these two relays would be my recommendation as a starting point.

This is exactly what it does. Never had to wait for a 2 hours, though. The longest was ~15 minutes, and it's usually <2 minutes. Thanks!