I changed out my FPDM yesterday. The original was a little corroded but hadn't eaten through the base yet, but I changed it out anyways since we are taking a trip into the mountains this weekend. The first thing I noticed is that I'm idling about 100 rpms more now. A little bit smoother. Another thing I did notice is that my shift points were a little quicker. Is this normal? Is the FPDM responsible for some of the actions of the transmission? Im not complaining by any means, hopefully I'll see a MPG increase as Im only getting 9 MPG city right now. The original was of course Motorcraft and the new one is made by Dorman. Original was on there for 193000 miles. Im suprised it wasn't as corroded as some of the other ones Ive seen with far less milage on them. Anyone have any insight on this? Maybe techrep and especial86 will chime in.

 

Your FPDM is responsible for delivering fuel according to rpm, tranny position, load, etc. if it was malfunctioning, you may not have been receiving adequate fuel pressure or volume, which can cause a rough idle, slow shifts, as your engine must coordinate with your tranny based on power available, rpms, etc.

There are way too many threads on here about FPDM's, an it would appear as though nobody understands that it is more than just an on/off switch for your fuel pump.

 

Did you disconnect your battery? If you did your PCM is relearning.

 

I figured it was a relearning process. I just wish I could see the schematics of the FPDM. I have read thousands of threads on here about it, but as lariatboy said, most folks just think its an on/off switch for the fuel pump. I knew that it controlled more than that, but just wanted to get down to the nitty gritty. My new VCT solenoids will be here tomorrow, so with that and the FPDM maybe my truck will feel like new again.