My MAP sensor is on the passenger fender about 6 inches aft of the starter relay.

 

Then, I'd bet that the buzzing is coming from your EVR solenoid, and that buzzing is doesn't indicate any problems.

 

no mine dost show the evr solinoid but ya that makes sence though.

 

have u pulled your plugs yet usually they can tell a story all them seves if u know what to look for. maybe that could be an idea. second thing pull an o2 senor out and stat it if it runs good u cat might be pluged i have seen that and they run like crap to.

 

> there but from the relay right next to it.
> Any idea what it does?

There are a few choices, as others have mentioned. Remove it and see what color it is to to sure. If OEM the bottom with be either brown or green and that is how it is listed at the parts stores. Though most stores now sell a generic ISO relay and socket and you just slice it in.

 

I thought the MAP sensor was mounted to the firewall and has a vacuum tube / line that connects it to the intake? At least that is how it is on my '87, and I don't think there was a change from '86 to '87 *shrug* There is also the resistor bank for the air conditioning / heater fan next to it, and then all the way over and forward are a few relays... I think 3? I don't recall exactly what the EVR solenoid is for, though.

 

the map sensor on my 86 b2 is mounted on the firewall too

 

Mine (86 and 87) were on the right fender and that is the only place I have seen them in Bronco IIs. Who knows, Ford is famous for changing things without notice according to production schedule/needs.

 

I'm wondering if people are confusing the MAP sensor for something else. There are a couple of things on the air box, but I don't think either of them are connected to anything electrical. The MAP sensor should have a vacuum line that connects from the intake manifold and runs along the passenger's side of the upper intake to the firewall (back of engine compartment) where it connects to the sensor, which is mounted on a bracket that bolts to the firewall. If I remember right off the top of my head, there's a wiring connector with 3 wires connected to it. Here is a picture of the MAP sensor:

 

Yep, mine looks exactly like your picture.

It is on the passenger fender right by the air filter box.

I've read a couple of posts that indicate it is on the firewall by the A/C evaporator. My Bronco II does not have an A/C. Maybe in those vehicles that don't have an A/C it is on the pax fender. (?)

By the way, after changing the DPFE sensor my mileage has gone back up to 20 mpg. Still stutters about once a trip but I guess i can live with it until it gets worse.

 

Ah. That could be the difference.... non-A/C equipped vehicles may be different -- I have NO idea why, though. I am wondering if I should think about replacing all of my sensors or at least double-checking them and pulling codes again as well as checking a few other things. I have a feeling that my mpg is starting to drop off or has been and it's time to start troubleshooting. Could be just the difference in climates from WA to VA as well. You may have other things going on that relate to your situation as well, which could also be linked to the gas in your tank. I'd run some de-watering stuff like HEET and see if it's just a matter of water in the gas. My main problem right now is most of the time when my rig is stone cold, I can start it up and then it dies, but when I re-start it, it stays running just fine. Wondering if it's the same issue you've had going on.

 

hey kernel, i had the same problem b4 on my 86, i replaced the iac {idle air control} valve and that fixed it.. it did the exact same thing you described, when cold it would start then immediately die,then i could restart it and it would idle just fine... i tried cleaning it first but it only lasted for a few weeks..then it started it again,so i just replacd it

 

my72,

Yeah, I think I read in some other threads about that issue. Wouldn't surprise me if it's a combination of that, the MAP sensor, and the EGR position sensor, among other things. I'll have to look through the tech section and see what all I can test and also pull codes and see what's what. Wouldn't also suprise me if I need to clean out the intake as well.