Cold weather starting issue

[Nick9thomas]

99 explorer XLS

Hey guys,

Having issues with car not starting in the cold weather after its been sitting overnight. Runs normal once started. Engine cranks fine just doesn't turn over. After its been running and turned off it will crank right up. Battery is new and tested out great. CEL reads bank 1 and 2 too lean. Not sure if the two are related because this code has been on for over a year now. I've cleaned the MAF and don't see any leaks. Maybe an electronic issue? Or an 02 sensor? Any help would be great.

Thanks

Nick
Athens Ga

 

[koda2000]

do you hear the fuel pump prime for about 2 secs when you turn the key to ON? i had this problem with one of Mountaineers and it turned out to be the fuel pump didn't run the first thing in the morning on cold days. once it started it was fine until the next morning. if you don't hear the pump run, try hitting the bottom rear of the fuel tank first and see if you hear it then (there's a small tear-drop indentation right under the fuel pump). you don't have to beat the hell out of it. once smack with a rubber mallet will do it.

BTW, the reason this happens is because the motor brushes wear down and the springs, which press them against the armature, weaken. when cold, the springs contract just enough to not put sufficient pressure on the brushes - then the pump motor doesn't run. if you bump the pump, it's just enough to engage the brushes and the pump runs. once it warms up it works until it gets cold again.

as far as your lean condition, this indicates you have un-monitored air getting into the engine anywhere after the MAF sensor. this can be a vacuum line, vacuum reservoir, pcv hose/elbow/grommet, upper and/or lower intake manifold gaskets or even a leak in the power brake booster or related parts. someone here even reported he solved his lean condition by changing his fuel filter, although i don't really see how, but whatever works.