So I just bought an 86 ranger and the vacuum system on this thing is a mess. They installed some crappy "cold" air intake and it looks like they just ripped off half the vacuum hoses. When I'm coming up to a red light or something and I let the RPMs get a bit low before I push the clutch in, it stalls.

I searched around for a factory air cleaner assembly but couldn't really find anything. If anyone is parting out their truck, I'd love to buy it and get rid of this piece of junk intake.



Anyways, I need some help identifying this stuff. Sorry for the dark flashlight pictures!




This is the side of the throttle body. The port just had nothing on it so I put a cap on it.








This random hose coming out through the firewall beside the brake booster is connected to nothing at all. I also capped the end off to prevent stuff getting in there. No idea where it's supposed to go. According to the confusing vacuum diagram, I'm thinking this hose goes to the fuel tank and it and the one coming out of the TB are supposed to go to the carbon canister?








Here's another port that was just wide open that I put a cap on.That other hose coming out of that fitting goes to a plastic box on the passenger side fender. According to the diagram, it's the EGR valve position sensor.








This fitting has one large line that is connected to the brake booster and 3 small ports that were previously capped. Not sure if they were capped at the factory or there are more missing hoses.





Any info that you guys could provide as to what is going on here would be greatly appreciated. Any photos of what this stuff is supposed to look like would be fantastic. I have a laundry list of work to do on this truck and this is really the only thing I need to do to get it running properly.

Thanks in advance!

Rob

 

The two larger vacuum hose look OK, the power brake and the PCV hoses

The EGR system is disconnected, 1st picture, there are 3 parts, the EGR valve in the picture(it has a wired sensor on it) and there will be a EGR solenoid, a value with 2 vacuum hoses, one hose from the intake manifold and one hose to the EGR valve.

There are two fuel lines that come in from the drivers side frame rail
One fuel line goes to the FPR(fuel pressure regulator) it has a vacuum port, it should have a hose running to intake

Do the vents in the cab work?
Or are they suck on Defrost?
To select panel or floor you need Vacuum at the selector in the cab
This vacuum comes from a Vacuum reservoir in the engine bay, a smaller black canister with two vacuum hose connected, one hose runs to intake and the other runs thru firewall on passenger side close to inner fender

The factory air box had 2 vacuum lines, one from the intake and the other ran down to the "pre-heated" air valve, when engine(air box) was cold the air valve would open and suck air from around the exhaust manifold to help engine warm up faster.


EVAP system, it had 2 parts, EVAP solenoid has 2 vacuum lines, one to the intake the other to the charcoal canister, canister also has a 2nd hose that runs back to the gas tank
There can be a sensor on the canister or inline with the hose to the solenoid

If you have an automatic transmission, A4LD. then there is a vacuum hose to the modulator on passenger side of transmission

No, don't have a diagram but should be one on the rad support

 

Thanks so much for the reply. I’m not home now but I’ll look this over in detail when I get home!

 

Hi again,

The vents work perfectly fine. It cycles around to every vent location with no problems.

Where is the vapor canister located? I’m looking all over, it’s possible the previous owner removed it entirely.

What lines are missing from the pictures I showed? Would they be causing the stall condition I described or should I be looking elsewhere?

Thanks for all your help!

 

Not all vacuum ports are used so a cap port doesn't mean something should be there.

Charcoal canister would be on drivers side of rad support in engine bay not on the front of rad support, if its not there then its been removed

In the last picture right below the Vacuum manifold is the FPR, it should be connected to above vacuum manifold.


Fuel injected engines use an air valve to set idle since there are no Jets like a carb had so "idle screw" won't work well.
Ford calls theirs the IAC(idle air control) Valve
The computer controls this valve
If it opens a bit idle goes up, closes a bit idle goes down, it is accurate +/-3rpm so very precise when working

In the 3rd picture the IAC Valve is in the center of the picture, looks like a can on its side, 2 bolts hold it to upper intake and it has a 2 wire connector

After engine is fully warmed up you can test if its working and if you have a vacuum leak
Warmed up engine is needed
Let engine idle and unplug the IAC Valves 2 wire connnecr
RPMs should drop to 500 or engine may even stall, either is good no vacuum leaks
If rpms don't change then IAC Valve is either stuck or you have a vacuum leak

Remove IAC Valve from intake
Plug its wires back in
turn on the key, computer opens IAC Valve all the way for startup, just FYI
Look in at the valve inside unplug wire connector, valve should close, plug connector back in, valve should open
It doesn't move very far, 3/8" maybe, but DOES MOVE

If its not moving test voltage on connector, should be 11-12v, red is +, other color is ground, key must be on to test
If voltage is OK replace IAC Valve
This could be why engine stalls

 

The charcoal canister does seem to be missing. No big deal I’d imagine.

I just tried unplugging the IAC while the engine was running and it did in fact stall.

There is a pretty significant intermittent tick coming from the engine - it almost sounds like a small exhaust leak when it’s at its loudest and sometimes it completely goes away or is significantly quieter. It doesn’t seem to matter engine temp or anything. Sometimes I start it and it’s there and sometimes it’s not. It’s there probably 70% of the time. I had attributed this to a lifter or something as I know the 2.9s are notorious for it.

Also the truck also idles a bit rough, nothing crazy but just a little lopey. I had assumed it was running poorly in general due to the vacuum leak which apparently doesn’t exist.

I’m scratching my head now, any ideas?

edit: also, any ideas as to what that hose coming through the firewall next to the brake booster is?

 

Hose in the firewall might have been for cruise control, there is a valve on the brake pedal push rod(at booster) that would release vacuum on Cruise servo if brakes were applied it was a backup cutoff in case brake light fuse was blown, brake lights would turn off the cruise electrically

Older distributors can get a little wobbly so rough idle that smooths out at higher RPM

Yes, on the 2.8l and 2.9l the two center cam bearings passed oil on to the lifters and rockers, as center cam bearing wore down the pressure to these would drop quite a bit, so they can be "ticky" does damage anything just noisy

 

I know this was a long time ago, but did you ever find out what was supposed to go to that first picture off the side of the throttle body? I'm having a crank no start issue and going over every vacuum line and was wondering what that went to.

 

your better starting a new post. if cranking and no start i dont think its a vacuum line. look for a post how to do a 50-50 test. checking for spark and fuel.

 

I actually got it to start today. I turned the timing back a bit on the distributer but i seen a vacuum line that i have no idea where it goes so i just put a screw in it to plug it and it fired. Hell of an exhaust leak though haha