Hello,

It appears there is an Air Cleaner BiMetallic Valve missing, so I'm trying to backtrack all the vacuum hoses and wiring to determine all necessary components to purchase and install. At this point, it seems only the vacuum reservoir is missing. Has anyone purchased one for this model?
Does anyone know what the EGR "Valve Position" is supposed to mean? Is it an actual part?

 

"Disconnected vacuum to A/CL Bi-Met" is the failure for tamper. So, based on research and this, it looks like i'm just missing a vacuum line from vacuum reservoir to the bimetallic valve. I have to do another visual inspection to confirm that everything from the bimet to the EVR is good and from the bimet to the Diverter Valve. More updates to follow.

 

All car makers have an "Air pre-heater" setup to help engine warm up faster, this also lowers emissions if engine warms up faster, which is why Calif. wants it working

On the 1987 Ranger there is a Cold Air Intake tube between air filter box and grill, that pulls in air from in front of the radiator support
There will be a vacuum operated valve on that tube, with, what looks like metallic dryer vent hose, on it, this hose runs to a metal "chamber" clamped on to the exhaust manifold
When engine is started cold, the valve closes and pulls in air from around the now warming up exhaust manifold, so pre-heated air is pulled in so engine warms up much faster

This vacuum valve is operated by bi-metalic thermal sensor on the air cleaner box, this sensor is mechanical, no wires, 2 vacuum lines, one to the vacuum source, like vacuum reservoir, and one to the vacuum valve on the cold air intake tube



EVR is the EGR system, just FYI
There are 3 parts to this system
EGR Valve, 1 vacuum line, vacuum operated valve that the computer controls, it is opened a little or alot to mix in exhaust gases to intake manifold, this lowers ignition temps to lower emissions
Vacuum line for EGR Valve is hooked up to the EGR Solenoid

EGR solenoid, 2 wires, and 2 vacuum lines, computer pulses 12volts to this solenoid to send vacuum to the EGR valve, pulsing voltage means the computer can open this valve a little or alot to control how much vacuum is sent to EGR valve to open it a little or alot
1 vacuum line to EGR Valve, and 1 vacuum line to vacuum source, which can be vacuum reservoir(VRESER)
This is also called the EGR Modulator

EGR sensor, 3 wires, and 1 vacuum line(in 1987), this is a vacuum "pressure" sensor, its feedback to the computer so it can "see" the amount of vacuum it is sending to the EGR Valve
Ford also used an EGR valve Position sensor instead of the pressure sensor on some years, this was attached to the EGR Valve and had a rod that was moved up and down as the EGR Valve moved, feedback for computer so it could "see" EGR Valves position

 

OK!
wow that’s a lot of info :)

So, this is what it looks like. I’ve identified the Valve and Solenoid, the Sensor I havent’t yet. Also is the vacuum hose diagram marked up with existing setup. I don’t see a reservoir canister so my guess it was removed with the bimetallic valve. The diverter is part of the filter housing (still existant) and is indeed missing a hose.

 

oops

 

Thanks @RonD , super helpful place to begin. I've taken photos and marked up the vacuum hose diagram. For sure I'm missing the reservoir, and it seems the A/CL Diverter and Bimetallic valves. Any additional insight would be helpful?

 

1987 Vacuum reservoir can look like this: https://images.restomods.com/00/s/MTYwMFgxNjAw/z/RvgAAOSw~FFgL9uy/$_57.jpg?set_id=8800005007

And old can, lol
It can also look like a round plastic Ball

The green vacuum line is on the EGR solenoid and EGR Valve(good), the black one should go the intake manifold or vacuum reservoir if you can find it

The top of air cleaner box should have 2 nipples, those are labelled "bi met" in drawing
Needs a vacuum source then a hose to valve in pre-heater, there is no order no in/out

 

Got it! So I just need the manifold vacuum into the vacuum reservoir, then that goes to the air filter box. Initial inspection, it's not visible. It's also difficult to find any documentation where the location should be for this specific model -- do you happen to know @RonD ? Lastly, is there any chance you know the model it is or is the tin can model interchangeable with any other?

 

No, don't know where yours would be

You can use any vacuum reservoir from any vehicle, my 1994 has a smaller one on top of the heater box in engine bay
Looks like this: http://i899.photobucket.com/albums/a.../Reservoir.jpg

Plastic tank with just one hose fitting because it uses a Check Valve "T" instead of an in line check valve
So the tank is hooked to the "T" and in you case the bi-metal valve would hook to open port of "T"
Vacuum source(intake manifold) hooks to center port of "T"
A check valve(like the one on power brake booster hose) allows vacuum to go thru into the tank so it has max vacuum, say 18", at idle, then when vacuum in the intake drops, i.e. accelerating, the check valve closes so vacuum is not pulled back out and stays at 18"

In theory vacuum devices don't "use up" vacuum, but in reality(real life) there are always small leaks, lol

If you use a 2 port vacuum reservoir(tank) then you also need an in line check valve

But from what I understand the Smog guys are not testing the system, they just see the open ports on the bi-metal valve and maybe the pre-heater valve on cold air intake, which caused the red flag
This system was often removed and never put back on the first time engine work was done on that side of the engine bay, lol

 

Any model? Wow, that's surprisingly compatible? What do you think of this one? It's the most affordable I could find.
Correct, they're not testing the system. It's a visual inspection and failed because a component is missing. Likely yes, and the previous owner passed inspection and since has minor engine work done. I suspect this is what happened.

 

Sure that one is fine, but get dimensions, those round ***** can be quite large

Picture of one here in its "normal" location on 1995 and up Rangers: https://www.explorerforum.com/forums...obe-jpg.39621/
Its on passenger side, bolts to inner wheel well front, fender is removed for the picture of course, lol
These got larger because vent controls in the cab were vacuum operated and EGR and other devices, so needed more vacuum storage space

But if you can find a spot for it then, yes, it will be fine to use
A local wrecking yard will have loads of these and smaller ones, as said, this is not a Ranger or even Ford thing, every gasoline engine vehicle will have a vacuum reservoir

 

@RonD woohoo! Got this all sorted.

unfortunately I am still failing the 25mph test, running rich. I replaced the air filter and it improved marginally but not enough. CO% should be at max .82, I’m at 1.40. New air filter lowered by .15 :(

 

High CO levels can be a few things

#1 ................O2 sensor needs to be changed every 12 years or 100k miles, period

Make sure MAP sensor hose is OK, no breaks

ECT sensor, not an expensive part, if its reading a lower temp than actual, engine will run Rich, not related to dash temp gauge

 

@RonD It’s about to hit 100K so makes sense. Do you know if there’s a single sensor on this model?

will check the MAP sensor hose and replace as needed.

May as well replace it too.

 

In 1987 2.9l there is just the one O2 sensor on the exhaust "Y" pipe

O2 sensors all use 22mm wrench size, 7/8" wrench is very close so can also be used
To remove old O2 sensor you can just cut its 4 wire lead so you can slip on a box end wrench or long socket
Don't try to use open end because it may be rusted in place and you will just round off the nut

When installing new sensor the torque spec is 30ft/lb which is just over "snug", lol, so you can use an open end wrench to tighten it
Put it on finger tight, then turn it 1/2 turn, be careful not to cross thread it, new sensor should thread in using fingers only

 

done! Will update when smog is done.

Old

 

OMG, that is OLD, a 2 wire O2 sensor

 

@RonD finally got around to going back today and after replacing the O2 sensor and MAP sensor, im happy to say she passed with flying colours. Thanks for all your help!

 

Good work

Thanks for the update