EGR valve replacement

[Ilovemy81]

Hi. I have a 81 bronco 5.8 351w engine, i got my bronco three months ago and had the engine rebuilt. The engine did not have an EGR valve so I went out and bought a new one for my baby, I put it on just fine but I don't know where to put the vacuum hose. There's no conncetion to the pvs valve. where else can i connect the vacuum hose? Someone please help!!!

Thanks Nigel

 

[Rons beast]

I'm guessing that you had an engine with an EGR port and was designed for an EGR. The valve itself was just not installed, correct?

In that case the vac line should go to a temperture controlled port, that supplies vaccum above the throttle plates.

( the valve should get vacuum only when the throttle is open and the engine is warmed up.)

Look for a vacuum tree in the manifold with 2 or more ports. One should be the vacuum supply and the others are vacuum out when the eng. is hot.

 

[miesk5]

yo NIGEL.

WELCOME!

For now until someone here can give you a pic or validated info;

Here is one Vacuum Line Routing Diagram in a 81 351W; Calibration 1-24P-R21

http://content.chiltonsonline.com/content/images/8576/images/85764154L.gif'>http://content.chiltonsonline.com/content/images/8576/images/85764154L.gif

by Chilton

See if you can find the calibration number

more diagrams:

Calibration 1-24R-RO

http://content.chiltonsonline.com/content/images/8576/images/85764156L.gif

Calibration 1-24P-R21

http://content.chiltonsonline.com/content/images/8576/images/85764154L.gif

Chilton Manual for 66-81 Bronco, Scanned Copy

Source: by Chilton via broncocity.com @ http://www.broncocity.com/66-81manual.htm

see Chapter 4 Emissions & Fuel System

page 144-145 describes the EGR Valve and a General diagram

mentions vacuum signal which operates the EGR valve originates at the EGR vacuum port in the carburetor. This signal is controlled by at least one, and sometimes two series of valves.

A water temp sensing valve (the EGR PVS) which is closed until the water temp reaches either 60 def F or 125 deg F depinding upon application, is always used.

acronyms (not nec. for your year/engine) complied from Seabronc, and others here.

A/CL: Located in the air cleaner

A/CL DV: Air Cleaner Diverter Valve

A/CL BI MET: Air Cleaner Bi-Metallic Valve

A/CL CWM: Air Cleaner Cold Weather Modulator

ACT: Air Charge Temperature Sensor, prior to 1992

ACTS: Air Cleaner Temperature Sensor

ACV: Air Control Valve

AIR: Thermactor, short for Thermal Reactor. CA vehicles are installed with it as standard. Air Injection Reaction is what it stands for.

AIR BPV: AIR BPV is the AIR Bypass (AIRB) Valve; also called the TAB (Thermactor Air Bypass) Valve

BV: Bowl Vent (on top of the float tanks)

CARB: Carburetor

CBD: Closed Bowl Distributor

CPRV: Canister Purge Valve

DIST: Distributor

DPFE: Differential Pressure Feedback

DV-TW:Two Way Delay Valve

EFCA: Electronic Fuel Control Assembly/ (Fuel Pressure Regulator (FPR)

EGR: Exhaust Gas Recirculation

EGRC/EGRV: EGR Vent/EGR Control

EXH HCV: Exhaust Heat Control Valve

EVP: EGR Valve Position

EGR: Valve Position

EVR: EGR Vacuum Regulator; also called EGR Vacuum Solenoid

FLTR: Filter

FPR: Fuel Pressure Regulator (check vacuum line)

HEAT VLV INT: Heat Vacuum Control Valve Intake, (next to carb)

HICV: Hot Idle Control Valve

IAT: Intake Air Temperature Sensor (Air Charge Temperature (ACT), prior to 1992

IVV: Thermactor Idle Vacuum Valve

LCV: EGR Load Control

MAN VAC: Manifold vacuum-Vacuum source; usually ref. to as Vacuum Tree atop intake manifold]

MAP: Manifold Absolute Pressure

PCV: Positive Crankcase Ventilation

PURGE: Vapor Canister Purge Valve

PV: Ported Vacuum

PVS: Ported Vacuum Switch (PVS) Valve

S: Spark port

SA-FV: Separator Assembly Fuel/Vacuum

SOLV: Thermactor Solenoid Valve

SV CBV: Carborator Fuel Bowl Solenoid Vent Valve

TCAC: Thermostatically Controlled Air Cleaner

TCP: Temperature Compensated Accelerator Pump

TK: Throttle Kicker

TVS: Throttle Valve Solenoid (aka Solepot, Dashpot)

or

TVS: Temperature Vacuum Switch

TVV: Thermal Vacuum Valve

or, TVV: Thermostatic Vacuum Valve (aka Ported Vacuum Switches; Thermal Vacuum Valve)

VAC: Vacuum

VCKV: Vacuum Check Valve

VCV: Vacuum Control Valve

VDV: Vacuum Delay Valve

V CK V or VCV: Vacuum Check Valve

VOTM: Vacuum Operated Throttle Modulator

VRDV: Distributor Vacuum Delay Valve (VDV, VRDV, DV-TW)

VRDV: Vacuum Delay Valve (VDV, VRDV, DV-TW)

VRESER: Vacuum Reservoir (coffee can style in earlier years; replaced by plastic style)

VRESV REST: on earlier years such as SEABRONC's 83 is a Vacuum Restictor/delay valve, it delays vacuum for a certain amount of time

VRV: Vacuum Regulator Valve

WOT: Wide Open Throttle Valve

 

[Bronc76]

I have posted some pics of my '79 EGR, not sure if it will help you or not.





The first pic has the EGR on the right side with the vacuum line leading to a valve on the left.

The second pic shows the vacuum line going to the carb from the bottom of valve. The other line goes to a port on the thermostat housing. (the line to the carb goes the right side under the carb)

Hope this helps.

 

[Ilovemy81]

EGR vacuum hose goes to a tee which has a EGR port vacuum hose connected. Then a hose from the tee runs to the EGR/PVS valve.

My system is not like that:/ there's a vacuum hose with no tee, running from the EGR port to the PVS valve. On the PVS valve there's no input for the EGR vacuum hose.

I was guessing? If I can cut the vacuum hose that's running to the PVS valve in half,put a tee on then connect the EGR vacuum hose. Would that work?

-Ron's beast

Thanks for the advice it's helping out a lot. Hope you have some more to give

-miesk5

Thanks for the info and the visual it helped out lots too, please keep it coming.

Thanks Nigel!

 

[bronco5.8]

It might be easier to block off the egr with a plate and find a fitting and do the same with the exhaust thats what i did on my 81 jeep and I did that six years ago but you will have to look at youre local laws it might be kind of a pain to find a shop that will pass it for a state inspection

 

[Ilovemy81]

-Bronc76

So sorry i didn't see your reply..... I don't have the valve on the right:/

-Bronco5.8

That's the way it was when I got it back from the shop, but that made the car stall :/

Thanks Nigel!

 

[Ilovemy81]

Ill take a better pic tomorrow

Thanks again everyone for the help!!

 

[Rons beast]

(I was guessing? If I can cut the vacuum hose that's running to the PVS valve in half,put a tee on then connect the EGR vacuum hose. Would that work? )

If you cut the hose on the outlet side of the PVS valve, and "T" it, it should work. The PVS is supposed to allow ported vacuum only after the engine is warmed up. That's what you want to the EGR.

Good Luck.

Let us all know how it works.

 

[Seabronc]

Attached is a picture of how almost all EGRs are connected. Ron is correct in that it also needs a heat operated Ported Vacuum Switch, http://www.lmctruck.com/icatalog/FD/full.aspx?page=47 . It is mounted at the water neck and opens when the coolant temperature is around 160 degrees. It is the green line shown connected to the PCV with a white line going to the carburetor vacuum port. The VDV shown in the green line is a (Vacuum Delay Valve) . It delays the vacuum signal to the EGR and is hooked in in the direction shown (white side to the EGR, black side to the input), (you may have to go to a junkyard and pull one of these off a junker, Black and white).

Good luck,

>-

 

[Seabronc]

(I was guessing? If I can cut the vacuum hose that's running to the PVS valve in half,put a tee on then connect the EGR vacuum hose. Would that work? )

If you cut the hose on the outlet side of the PVS valve, and "T" it, it should work. The PVS is supposed to allow ported vacuum only after the engine is warmed up. That's what you want to the EGR.

Good Luck.

Let us all know how it works.

It won't function properly when hooked up like this.