Is That A Pump I Hear at Engine Start??

I've got 2000 Windstar with a 3.8L and 101,000 km.

Since new, when I put the ignition key to engine run (just before the key goes to engine start position) and the dash lights go on, I hear what sounds like a pump (priming pump???) or a motor moving to position, coming from the engine bay. I could hear it up until 2 weeks ago when I fixed the P171/174 CEL codes (replace left bank rocker cover and replace isolator bolts, etc).

Since then, I can barely hear it and it sounds like it's coming from the rear of the van, so it could even be a different pump(?).

Sorry to sound like such a noob, but does anyone know what this sound is and where I might start troubleshooting it.
I re-checked all the connections from the P171/174 fix. They all look ok.

What did I miss??

Thanks.

I don't know about the noise that you have heard from the engine compartment before your 171/174 fix however what you are hearing now from the back while you put your key to on is the regular and normal sound of the fuel pump, located in the gas tank.

I thought it might be something like that, presurizing the fuel system. It was more audible before. More faint now. I can hear it, but I have to listen more carefully. The engine starts ok, no change in starting. I can't think of anything else that might need priming before engine start.

Thanks.

If the day comes and your Windstar doesn't start and you don't hear that pump sound, you know where to start troubleshooting (fuse, relay, harness, or the pump itself). First, though, check the fuel pump emergency shutoff switch and reset if necessary.

Maybe Wiswind can jump in here, but I think your year van has the electric IMRC. At startup, it may be going into "startup" position, and after the 171/174 repair, you may have eliminated the source of "amplified sound" from the IMRC and now operates quietly. Or, for whatever reason, you were just hearing the sound of the fuel pump presurizing being amplified up front and now after the repair, eliminated whatever amplified it.

I'll check the IMRC. Thanks.

I'm curious if anyone else hears the 'pre-start motor' that I hear....or am I the only one? In which case, I wonder if there was something wrong and I just happen to fix it when I did the work for the 171/174.

Anyone else's 2000 winnie w a 3.8L hear something from the engine bay when the key is held at ignition ON...before putting the key to "start"??