03 D2
When you turn on your key to the last position before start and with your hood open does the idle air control valve make a humming or buzzing sound. I have never noticed this before it may just be running? Is it supposed to be running, buzzing, humming when the key is on?
trying to troubleshoot a problem and wondering if the noise is normal?

 

Mine does it too.

Best I can guess is that the orifice opening is controlled via PWM (pulse width modulation) rather than a stepper motor like the older cars.

 

hmmm, guess I've just never noticed it.
thanks

 

Scary thing is - you will hear that time to time when the key is removed from the Discovery II.

Only way I found to halt it is restart the engine then take the key out again after shutting down the engine.

 

yea that would be bad and would probably drain the battery.

jfall, where can I buy a fuel pressure gauge with the right size adaptor for the schrader valve on 03D2.
Do you know what size that is. Most all of the fuel pressure test kits I see say not for bosch.
Only the high dollar ones say fits most cars and trucks world wide. I don't want to pay upwards of $100 for something I'll probably use only a few times.
I have a fuel pressure gauge now but it has the wrong size threads and I don't know where I can find the correct adapter or what size to look for. the adaptor cant just be a fitting from lowes it has to have a valve stem in it to depress the stem in the schrader valve on the fuel rail.

 

have you tried the local autoparts store? most loan or rent tool these days.
I would assume theirs would have several adaptors

 

Well I just went to autozone and the one they had for loan didn't have the right adaptor either. On their website it shows one with what looks like 50 adaptors but the one he had didn't have many at all. They didn't have any loose adaptors for sale there either. I may try advance. Not many choices around here. Orielly's didn't have one and said he couldn't order just the adaptor but could order the whole kit but it was way high and I'm sure I can find one for a better price. If he would have to order it I could just order it.

Thanks though. I'll eventually figure it out. I see adapters on amazon or ebay for a small type schrader but, they say for ford and not sure if it's the same. I doesn't necessarily have to fit my gauge I can cut the hose on the gauge and splice an adaptor in if I need to. I would buy any kind if it fit the truck. same size as a tire valve, i took off the cap and it would screw right onto my valve stem on the tire
.
I guess I should probably just spring for a good kit with the right adaptors if I am going to tinker with these trucks. It would be nice if I could find a gauge that just fit these trucks without all the other adaptors because I rarely work on anything else.

What is the name brand or model # of yours? If you don't mind me asking? Or if you see the right one anywhere on a website if you could send me a link.

thanks again for all of your help!