Intermittent starting problem

[shrink645]

I've been having an intermittent starting problem with my 97 explorer limited for about a year. It's the 4.0L SOHC. It started as happening about once a month but is now happening weekly. Basically, at random times it cranks and the engine turns over but doesn't start. Sometimes it takes 3 -4 times and others about 10 times before it starts but it always starts.

From some research that I've done here are some things that I have replaced.

1) battery, plugs, wires, fuel filter
2) IAC valve
3) PCM relay
4) Fuel pump relay

Any other suggestions would be greatly appreciated.

 

[BrooklynBay]

Welcome to this forum! Did you do a fuel pressure check, and scan the PCM for codes? The fuel pressure regulator might be bad. Did you test the ECT sensor?

This link might also help you: http://fordfuelinjection.com/?p=29

 

[shrink645]

Thanks for your reply.

I have not checked the fuel pressure or scanned the PCM. I unfortunately don't have either of those two tools. Those however, are definitely things that I am going to pursue. You mentioned the ECT but the link you gave me directly referenced the ACT. Did you mean the ECT? I do have a volt meter so that can be my next check.

 

[BrooklynBay]

Sorry for the confusion. The ECT is the engine coolant temperature sensor, and the ACT is the air charge temperature sensor. Both sensors look similar to each other, and have a similar resistance scale, but are designed to measure different things. One measures coolant temperature while the other measures air temperature on the intake. Both adjust the mixture. If they are out of specification, they could cause a rich/lean mixture causing flooding or hard starting.

 

[marragtop]

When it won't start, do you hear the fuel pump prime?

 

[witchdoctor]

Try a search for crankshaft position sensor. Sounds like the same symptoms I once had, and that was the culprit. $20 to 30 part.

 

[FordTony]

I had the same problem when my fuel pump was on its way out.....one day it just wouldn't start......check your fuel pressure.........has the fuel pump ever been changed?

 

[trevell407]

I second the fuel pump being on its way out,
Try turning the key 2 or 3 times before you start it to prime the fuel.
I have the same problem with mine,
The actuall fuel pump works fine
but theres some kind of ball in it that rolls back and keeps the fuel from going back into the tank when you turn yr truck off and it gets stuck in there somewhere.

 

[outdoorman99]

i've got the same problem. did you figure out the cause?