Our 99 Ford Expedition developed a strange problem starting about 8 months ago.
When the problem occurs, the engine cranks fine, but does not start (almost like it is getting no fuel). The strangest part is the random nature of the problem. We have noticed it only occurs after have being driven on an extended trip (+3 hours) and only after being left sitting overnight. If we wait a undetermined amount of time (1-3 hours), it will finally start correctly like nothing was wrong.
Our mechanic has looked at it and cannot find any main reason (no faults found with the computer codes, etc). As a precaution, the fuel injection system was cleaned, new fuel filter and tune-up was done (all which was needed anyway), but the problem still occurred on our last trip.
I don’t believe it is the fuel pump since we never have hesitation problems with it while driving. Once it starts correctly, I can turn it off and start it right back up.
Any ideas would be appreciated
The next time the no-start condition occurs, turn the ignition to the off position. Now turn the ignition to run position so that the dash lights come and then turn it off. Repeat this a half dozen times and then try starting the engine.
If the engine starts right up after doing this, it means the pulsator valve in the fuel pump assembly is defective, and is allowing the gas to drain back into the gas tank from the fuel rails and fuel line. So you can either perform this procedure each time the vehicle sits for an extended period of time, or replace the fuel pump assembly.
Tester
Thanks - I will try that the next time this occurs and see what happens
Does it start if you give it just a little pressure on the gas pedal? If so, it is probably the IAC (idle air control) valve. It is not the classic description of a bad IAC because that usually involves some two-footed driving to prevent stalling until the vehicle warms up. It is worth a try, though.
Nope - giving gas or not does not change the condition. I had read about the IAC the last time it occurred but as you stated was not exactly the description of a bad IAC.
I am having a somewhat similar problem with my 99 Expedition. Did you find a soulition?