2000 4.0 idle problems

[old ford fan]

My 200 Ford Ranger is having idling problems. On initial start up, it will cut completely off unless you assist idling with the accelerator. Then, it will idle at very low rpms (approximately 300). A quick bump of the accelerator will pick it up to normal (900 rpms) until you hit the accelerator again. It is NOT throwing the check engine light on. Any thoughts?

 

[schroeder_ce]

Hard start

I am having a very similar problem. After my truck sits, 8 hrs at work, overnight, sometimes for short periods(quick trip into a store), I'll start the truck, it'll go to 1200 rpm then just die. This will continue until I wait long periods with key on engine off. Also at other times it does exactly as listed above, and idle very rough at 200-300 rpm then die. Working the throttle does not help, it only causes backfires.(I have only worked the throttle once, not wanting to cause damage since I don't know what the problem is)

One odd thing I have noticed is if I turn the key on but do not crank, waiting until all dash lights go out(airbag is the last one) then repeat the process a second time, she will start right up and run just fine. There are not driveability issues once she starts up. So I'm thinking I'm loosing prime on the fuel system.

I'm thinking a fuel problem. Any fuel system schematics? Is there a check valve in the system?

I have not had time to troubleshoot, but did check for codes. None

 

[old ford fan]

I got mine taken care of. It was the Idle Air Control. Thanks to this forum for the help!!! Yours does sound fuel related. Turning the switch on and off like that a couple of times primes the pump, then when it sets it is leaking pressure somewhere.