Phantom Starting, need a real master.

[Sponrad]

My 03 4cyl ranger has a phantom starting problem that I'm trying to figure out. Sometimes when I try to start, the engine only cranks and never turns fully on, just cranks and cranks. This happens about 1 in 15 starts at this point (varies). It usually occurs when the ranger has been sitting in the heat for a few hours before trying to be started, this could be a random coincidence however. So far the pattern has been that it will start up fine a few hours after having a failing start.

Things I have ruled out:
Battery- it is new and charges fine, the engine cranks very healthily, terminals and grounds are clean
Coil- suspected this at first and replaced it
Fuel- really dont see how it could be this since when it does turn on it runs fine, never chokes or bogs

Suspected:
ECU- this might be affected by the heat when the car sits in the sun, seems like electrical stuff would be messed up by that more than anything else
Fuel filter- its been suggested to me by a friend so Im going to go ahead and replace it, but i have my doubts this is the problem

Didn't throw up any codes when i got the computer checked; the check engine light does not turn on. It definitely runs fine when it starts so im fairly lost here. Two mechanics ive taken it to have had no suggestions either. It doesn't help when you tell the mechanics there is a problem and it starts ten consecutive times and runs fine in front of them.

If any of you have any ideas or suggestions they will be greatly appreciated, I'm beginning to lose it here.

 

[Monty35]

I had that exact problem on both of my older rangers (88, and 92, one 2.9 and one 4.0) both were fixed by replacing the inertia switch under the dash on the passenger side. The intertia switch is used to shut off your fuel pump incase of an accident

 

[sonyes]

The inertia switch went on mine over the winter. When you turn the key to the on position do you hear the fuel pump engage?

 

[Sponrad]

Inertia switch sounds like it could be a winner, thanks for the suggestion on that gonna give it a go. http://www.therangerstation.com/tech_library/InertiaSwitch.html this sounds exactly like my problem and I wish I had read it before.

The inertia switch went on mine over the winter. When you turn the key to the on position do you hear the fuel pump engage?

Yeah I can hear it.

 

[Jspafford]

Well if you can hear it than that's not the problem. It shuts the power off to the pump.

 

[snake]

My vote is for the fuel pump relay. Just switch it in the box for another one like it and it won't cost you anything to find out.

 

[naford]

Try just turning the key to on wait 10 seconds then trying to start it. This will charge the fuel line to the injectors.

 

[skinner]

You need to close in on the problem much more before you go throwing money in the wind. Mine did something similar when the Fuel pressure regulator was going(and then, it started running horribly). If you can hear the pump coming on when you turn key forward, rule out the switch and the relay. If not, you've got it nailed.
We need more information.

 

[Sponrad]

Youre right. Ok so switch and relay are definitely not it then, I can hear it.

I can go more in depth about some starting stuff. I dont know what its called when you start and the rpms are higher than normal for a few seconds before coming back down to normal. On some starts that will not happen for me, it starts and the rpm needle rises to the exact idle spot. When I get a start like that if i give it gas too fast it will die sometimes. If i barely tap it, it goes high rpm for a few seconds like normal and then im free to drive it. It doesnt kick into that high initial rpm phase.

Most of the times that it is a bad start, the first attempt sounds extremely close to going all the way. Its the second and then on attempts where it just cranks and cranks endlessly and then i have to wait a few hours for it to work again.

Thank you for all the replies so far.

 

[rboyer]

Did you check for spark while it wasn't wanting to start? Spray starting fluid in the intake?

 

[snake]

It CAN be the relay because your problem is intermittent. That's how they act when they go out for some reason. Nature of the beast- and doesn't cost ANYTHING to switch two in the box...

 

[f1502rngr]

It CAN be the relay because your problem is intermittent. That's how they act when they go out for some reason. Nature of the beast- and doesn't cost ANYTHING to switch two in the box...

That is right, when it does this again, just open your hood, then on the drivers fenderwell there is a fuse box,open it and take the A/C relay out and swap it with the fuel pump relay (all the relays are the same).

 

[Sponrad]

Ok. I purposely left the truck outside today, and its been a warm day, and the problem turned up again. I definitely did NOT hear the fuel pump do its initial wind up when I turned the key to on. This is different from what I said before. I hear an electronic click noise coming from somewhere but no pump.

I swapped two relays, the a/c and fuel pump ones, and it did the exact same thing, no pump noise but an audible click. So I dont think its the relays unless they were both bad somehow. Im hoping it is the inertia switch; I already ordered that and should have it ready to install soon.

Thanks for all the help again, I feel like this is progressing.

 

[snake]

make it do it again and this time slap the dogcrap out of the bottom of the tank. If it runs then, the pump is about to go bad (sticking).

Remember tho, leaving the key on and slapping won't do it. The key must be cycled to see if it is working.

Edit- also, check the wiring connectors underneath the relay. Had a few on here that found faulty connectors inside the relay box- and that one drove 'em crazy until they figured it out.

 

[f1502rngr]

Seriously doubt it is your inertia switch, your fuel pump sounds as if though it is going out on you.