1995 Explorer limited wont start untill fuel pump stops

[krutiskarajas]

I have a 1995 Explorer that wont start after sitting for a while.
Usually I hear the fuel pump for a few seconds, when it goes off, it will start.
Now the pump stays on for 10 min, and it wont start while its on.
I have replaced the ECM and fuel pressure regulator.

The pump runs continuously as long as the key is turned forward, until it finally stops 10-15 minutes later. The engine will not fire until the pump stops. It cranks fine, but there is no injector pulse present until the fuel pump stops. The check engine light is on (as it should be)while the key is forward. It blinks once, when the pump stops. This & the lack of fuel pump noise tell me that the engine will fire.
After the pump stops the first time in the morning, it will operate normally throughout the day, provided there is not much time between uses. It seems that the problem exists only after sitting (and not being run) for an extended period (overnight or after work)
Help

 

[RomeovilleIL]

Check the pressure at the schrader valve first. If not giving you immediate constant pressure (for 95 I think its around mid-30's), then either you have an obstruction, weak voltage to the pump, or a bad pump.

Suggest you do a search for the no-start testing procedure.

 

[krutiskarajas]

I guess I'll have to buy a pressure tester.
I don't think its an obstruction or a bad pump, because once it starts, it runs great all day. this only happens if it sits for a while (overnight).

 

[96eb96]

I guess I'll have to buy a pressure tester.
I don't think its an obstruction or a bad pump, because once it starts, it runs great all day. this only happens if it sits for a while (overnight).

I would start looking at the idle air controller. The TSB for it has very similar symptoms.

Try holding your gas pedal down a bit when you start and see what happens.

 

[96eb96]

Reading this again I will also say to check the fuel pump relay. Maybe it is sticking?

 

[krutiskarajas]

Thanks for all the suggestions, but it runs great once it starts, so its not the IAC, and i have replaced all the relays.
This is baffling me?

 

[krutiskarajas]

Someone on a different forum had the same symptoms as mine. Their issue was not resolved but the symptoms are exactly the same as mine

"The pump runs continuously as long as the key is turned forward, until it finally stops 10-15 minutes later. The engine will not fire until the pump stops. It cranks fine, but there is no injector pulse present until the fuel pump stops. The check engine light is on (as it should be)while the key is forward. It blinks once, when the pump stops. This & the lack of fuel pump noise tell me that the engine will fire.
After the pump stops the first time in the morning, it will operate normally throughout the day, provided there is not much time between uses. It seems that the problem exists only after sitting (and not being run) for an extended period (overnight or after work)

 

[stroker331]

Can you put a presser tester on the fuel system to see what the PSI is doing? Also have you checked grounds from the ECM? I know they can do weired things.

 

[krutiskarajas]

can anyone give me a wiring diagram for my 95 explorer, so I can check the ground to my PCM

 

[koda2000]

free wiring diagrams:

You can find one at http://search.ebscohost.com/. Use RRCC and rebsco when signing in

 

[krutiskarajas]

Great resource koda2000! Thank You!