hard start

[mike0179]

HI every one!

I have a 99' Ranger, 4.0 that has a hard time starting when the outside temp is below 30 degrees and it sits for several hours. I have replaced the battery and cables, iac, iat, ect, fuel filter, cleaned the maf, changed the plugs and wires, and lower intake gaskets, had the coil tested. it will start and idle realy rough for 10 to 20 seconds and is fine after that. My mechanic tested the pressure for leak down and stuff and said it is fine, but he never had a hard time starting it. ( it was in a garage) Could the pressure regulator be causeing low pressure only when it is cold and it is haveing the problem? I cant hear the pump prime for 2 sec. should you beable to for sure with this model? I dont hear it when it is running either however. Some times when its really cold out it will start, sputter and some times die. on restart she fire right up. Once in a while it will start rough when it is warmer out ( low fifties) it seems like its always moist out durring that instance. thanks to all.



mike

[F150hybred]

Sounds to me like the fuel pressure regulator is leaking fuel into the vacuum line that hooks up to it. After sitting for several hours, remove the line from the regulator and look/check for fuel in the line. If fuel is there, replace the regulator.

[Explorin94]

Change your coolant temp sensor, the one that goes to the computer. The sensor is giving the computer a false reading and putting it into a rich condition.

[mike0179]

Yes, i have changed the ect that gos to the ecm. im thinking im going to have to check the pressure while the problem is happening, cosidering it checked out under normal conditions. im at a loss here.

thanks mike