MY E150 FORD VAN WHEN GIVING IT GAS IT LOOSES POWER AND MAKES A POPING SOUND WHEN GIVING IT GASS AND THEN FINE WHEN BACK IN PARK

Sounds like two different problems - the brake light switch and the speed sensor in the transmission.
Does the speedometer work ?

please give more details..

have the linkage adjusted

stop replacing parts and get the ingine analysed, sounds like a map sensor or airflow sensor, a code checker won't tell you anything if the problem is not registerd in the memory

coud be the shroud on the muffler under the van or loose muffler hangers .........
but could be anything loose under or if inside check mouldings seats dog house console dash .....

the heater core is located in the black box that is in the pictures (see below). To get access to it, you will need to remove the blower housing. The blower housing will separate from the main HVAC box, and will give you some space once it is out. Then we need to wrestle the main box loose from the firewall. That means dealing with the A/C pipes, heater hoses, vacuum hoses, mounting stud nuts under the hood and mounting bolts inside. Once the box is moving, the dash needs to "get floppy" so you can pull back the passenger side far enough to give the main HVAC box enough room pull away from firewall, and to "roll" back towards you. At this point the heater pipes will be visible, and the cover that contains the heater can be removed. It's a big job. Your car has A/C. The description in the haynes book is for a car w/o A/C. If you're not comfortable with plastic dash board removal, this job is not for you

you need to have someone to be near the back of the van when you turn the key to listen for the sound that should be coming from the gas tank your fuel pump if you do not hear anything you fuel pump is out try these websites www.alldatadiy.com and www.autozone.com if all fails stop by your local library and get your hands on a Haynes auto repair manual for your van wish you the best of luck Michigan Man.

This may mean a number of things, it could be a bad distributor cap, rotor and wires, or the intake valve or valves are burnt. Buy a compression tester and test the cylinder compression they all should be no les than 100 psi or the the engine needs a valve job, especially if one is down to 50 psi and the rest are at 130 - 150 psi.

it is broken buy a new assembley