99 ranger fuel system problem.. need help

Do you have check engine light, what is the code if you do. My brother had a 2000 ranger and the codes helped me fix it.

Reves by it's self , that's the PCM/ECM - engine computer controlling the IAC - idle air control valve . Try some injector cleaner ,fuel system cleaner !

Josh, have you tried simply replacing all fuel in the system? Especially if you have been using ethanol-based fuels, your fuel may have a high water content, or may even be contaminated with something else.
Also, if your engine is a TBI engine, verify that your COLD INJECTOR is working (and not clogged).
Incidentally, a bleed-down to 40 is not horrible! If it fell below 30 or less overnight, I'd suspect a stuck injector or bad pressure regulator... but 40 isn't horrible.

Bleeding the fuel system is typically only needed on high pressure systems like GDI and Diesel vehicles, and only to get them to start if they run dry once.
If your engine keeps running but the idle speed moves up and down there are many things that can cause that. More information is always helpful. Does it always do it whenever the car is running? Or does it only do it conditionally (IE Only when 1st started in the morning, only after warmed up or getting off the dreeway, only with AC on or at night...describe as much as you can.)
Most newer cars have computer controlled idle strategy that wants to idle the car cold around 1000-1500 rpm (After an initial higher rev called a FLARE) and then bring it down in 3 or 4 minutes to 700ish rpm. If it CANNOT bring it down by normal means, then many resort to something called FUEL CUT IDLE where it actually turns off the fuel momentarily and the RPM will drop because the car is stalling and running out of gas...then back on and it starts to rev back up and when it gets too hiugh it turns back off. Cars that do this can have annoying surges from 500-2000 back and forth at idle forever.

a vacuum leak or MAF meter problem can cause rough idle. ALmost any engine code that turns on CHECK ENGINE lamp may be suspect, does it have any current fault codes?

As well, consider Sticking manifold runners, EGR systems, and temperature sensors all can cause surging, so can a defective Oxygen sensor, slightly jumped timing, and dirty throttle plates the ECM wants to close more but they wont due to dirt. If its not something fairly obvious, it may require deeper checking.

Is the check engine light on when the engine is running ?
You'll have to figure out if it is a fuel problem or electrical problem.
Have you checked fuel pressure yet ?

yes there is and idle vacuum control on this as i have just fixed mine i was going to replace i but it wasnt cheap,i took it off and sprayed it with brake cleaner as it has a rotating piston inside ,i first tapped it with a screw driver while it was running and it slowed the idle down ,then it got cleaned do not lubricate this as it operates dry, it sits on the right hand side of the air cleaner near the back of it looking from under the hood hope this helps.

check your fuel filters, fuel line, and fuel pump

My engine light is on in my 199 ford explorer and I was told it is the o2 sensor 1 and 2 what does this mean?

Sounds like the idle bypass valve is nfg. Try checking engine codes first. Try this link, you'll find it helpful. http://autorepair.about.com/od/troubleshooting/a/OBD_codes.htm . If you need to know how to check the codes, ask back here, I'll explain. Hope this helps.

vacuum leak someplace for the low idle problem,Fuel filter clogged, bad fuel, spark plugs need changing,for the cranking problem.