any ideas on what it could be? 99' ranger extended cab 3.0L....it makes me sad when it happends but...i have no idea what it could be...some people told me fuel pump....but im not positively sure...

 

More info: does it KEEP running when you let up on the gas?

Once you start it, can you drive it normally?

Any other symptoms?

 

yes it keeps running once i start it...and i can run it normally

 

there are no other symptoms...you got any idea?

 

Yes. Try this.

Turn the key on (listen for fuel pump, runs about 1 sec.).
Turn key off, on again, FP runs for 1 sec.
Repeat. Repeat. Repeat. Do this on/off about 6/7 times.

Crank it to start. Does it start normal?

If yes, you are losing your fuel pump pressure by leak-down. Folks will chime in and help after you answer this key question.

It COULD be the fuel pump itself (internal check valve), but it could also be a leaking (stuck open) injector, fuel line leak (look for drips and smell). I am unclear on the fuel pressure regulator, it should be on/near the fuel rail. It may be the culprit.

There is also a test fitting you could hook a gage to and SEE it leaking down.

Report back!!!!

 

Also possibly a bad throttle position switch, bad temperature sender for the PCM, and some other stuff.

I like the leakdown theory. But I think once you start cranking the fuel pump runs so I don't think that's it. If the fuel pump is running, you should have enough pressure to start or you wouldn't have enough to run.

 

i will try that 2 morrow....but i have had someone else say it may have been the fuel filter?....dunno...but i am gonna get to the bottom of this sad...sad...problem...haha

 

i tried turning key on and off....it started after the seventh time....so now it should be that im losing fuel pressure by leak down?

 

Try another test. Turn the key on, leave it on for 15 seconds or so, then start it. Just wondering.

Fuel filter? If it was clogged, then you'd have problems delivery power at high RPMS. Starting the vehicle requires very little fuel delivery and the filter is not a likely candidate.

It's also possible that the fuel regulator on the rails up front needs "time" to start working properly. It may be the source of the leak in fact. You can use a 60 to 100 pound range tire gauge to check your fuel pressure (brass gauge, not plastic). There's a fitting under a cap on one of your fuel rails that your injectors hook into. Try getting a pressure reading and that will tell you the story as far as do you have enough fuel pressure to start.

 

i checked my fuel pressure....its good...my pump is good....so i have just a few more things to check...if there is no problems....then i'll just live with it

 

What I think is happening is that when you shut off the vehicle, the IAC valve (on the throttle body) is slamming closed. Whenever you go to start, it's sticking until the constant pulsing from the PCM breaks it loose some time after you first start turning it over. That's why I said to just turn on the vehicle and don't try to start it for awhile, then turn it over it.

Regardless (because that may not prove it), take your IAC valve off the TB and clean it with some carb cleaner. I think you'll find the problem goes away.

The key to this diagnosis to me is: you have full fuel pressure, but it doesn't start until after a period of time, or you give it air before that.

 

you can eliminate the tps. that is not the problem. If he doesnt have any hesitation or cutting off from idle to any application of the gas, its not the tps. We just had a TPS sensor go bad on one of our trucks.

Do like n3elz said, take the IAC off, clean it with carb or TB cleaner and it should be good to go.

 

Sounds good. I only mentioned the TPS since it "moves" when the gas is depressed and I was hunting for possibilities, lol.

 

sorry for being late...had to work...ok i'll give the IAC valve a try thanks for your help guys

 

I would check your battery connections and see if you can get a reading off it. Might be getting old and sitting at 9 volts... Im not sure what the least amount of volts are trucks will start at, some cars wont take less then 11, others will start at 8 but slug to do so. Also like they said, I love the MOPAR carb cleaner (white can with blue lettering) Its amazing stuff, if you spray that down ur intake and clean your MAF with break cleaner you should be set. you could also disconnet your Coolant Temp sensor and try to start it, might set off a check engine light though.

 

maybe dirty connections??