O2 sensor(s) and dual exhaust 91 4.0.L

[piedrarock]

First of all , Thank you all for your input and suggestions , starting a month or so back re: gender of ecu ( auto) , fuel pumps etc .
Ive talked to some FORD techs at the dealership today as the haynes manual is not 100 % clear about o2 sensor( s)
talking to three techs today , one says 1 , his computer only goes back to 94 , one says two heated sensors , and the last says two though he stipulated his info is not 100 clear , thats his interpretation of he fuzzy wiring diagram pics he could find.

The reason Im on this quest is my thinking about the dual exhaust that I put onto the engine shortly after installing it in the back of my Karmann Ghia .
So obviously serpentine belt is at extreme back of car , exh. manifolds on each side of engine recieve about 20 inches of 2inch plus or minus tubing that curves back to attach to a muffler on each side of engine bay faciing to rear of car.
The electrical tech from where I work , he services , trouble shoots EVERY THING hammerhead crane (hi rise construction ) , mobile cranes and lastly but not least automotive as well .
Im hoping he will help me with the harness work and integrating it into my VW.
He has some reservations re: a single o2 sensor (if indeed it is only one and how to make that work with a established dual exh. system .
Can I ask what does ranger station nation thinks?






88

 

[RonD]

Your 1992 will run Batch Fire fuel injection, on a V6 that means 3 injectors open at the same time, then the other 3 open
Usually its 1, 3, 5, and then 2, 4, 6, so odd and even

So one O2 sensor is fine, the 1993 and 1994 4.0l Rangers did have 2, so you could get Lean or Rich codes on bank 1 and bank 2
My 1991 4.0l diagram just shows one O2 sensor, so you could only get a general lean or rich code

Because of Batch Fire one O2 sensor should be fine, computer can tell if oxygen level is OK on the bank its on, so will run air/fuel mix for both banks based on that
In V6 Rangers the one O2 sensor was after the "Y" pipe so sampled both banks, but it couldn't tell if ONE BANK was lean or rich, just if the engine was running lean or rich in general

So just sampling one bank is the same thing......................almost, you could have a lower intake gasket leak on the non-sampled bank, but you would hear pinging, high idle or rough running so there would be "signs"

Calif sold vehicles required EGR Valve and dual O2s, also cam sensor for sequential fuel injection, pre-1993, so it its a Calif 4.0l.....................
But your wiring harness would have hook ups for 2 O2 sensors, and EGR solenoid, and CAM sensor

O2 sensor only sees Oxygen, same sensor on a 4cyl, V6 or V8, only seeing exhaust from 3cyl doesn't change anything, obviously, since they did end up using 2 O2s on a V6, 3cyl each
So O2 doesn't see "flow" or anything related to engine operation, its just "sees" oxygen content in the exhaust passing by it



I would say that's a tight fit.....................but its a no fit, lol
Reminds of Young Frankenstein......."What hump?"

Where are the radiators?
I am sure there has to be 2 shorter ones up front

But jeeze, what a fun project

 

[piedrarock]

Hi RonD , thanks for your ever always easy to understand explanations .
When I order an o2 sensor , are they mostly universal , or is there certian sizes and or capacity to geta good read on the o2?
I will get the clamp on type that i can put onto tubing just b4 muffler, I dont want to have to cut into exhaust and weld or clamp a sensor thats already mated permanently to a little length of tubing.
As for a plan B incase of one o2 sensor not doing the trick and obvious cel codes and or poor performance would you have a hail mary in the back of your mind ( splicing the wire and putting a sensor on other side , or some type of jumper circuit to fool sensor for example) ,

yes it is quite a hump originally when I did the bodywork and flares with vw engine , i molded on two scoops to force air into engine bay , I had to cut the back half of them for engine and then mig weld some ribbing , then sheet metal to close around engine ,
moved hinges from engine cover ( factory they were closer to back wind shield ) now they are reversed for a suicide effect and hood is hinged at bottom , near the exhaust.
I forgot about the cats winter house in the back of the car, heated with a light bulb in coffee tin for warmth in case your wondering what the solid insulation is in the back seat
Can I ask in what capacity you worked at Ford ?, I cant see all that knowledge coming from just wrenching on weekends

thanks again Ron

 

[RonD]

No, never worked for Ford, lol

The computer only has one O2 sensor hook up so only one can be used, you shouldn't "splice" a 2nd one in
Yes, you use a narrow band(.1-.9volt) universal O2 sensor, original was Bosch
These are all heated O2s so 4 wires and there needs to be a fuse on the Key on 12v heater wire, 10amp

You could install a 2nd O2 on the other exhaust pipe and switch between them every few weeks, just to make sure both banks are in sync

Wide band(0-5volt) O2s where used in the mid late 2000's on some Fords but all Rangers used narrow band thru 2011

 

[dvdswan]

That will be one fun Ghia when done.

 

[piedrarock]

It was only a wild guess that you worked on a ford or two .thanks on your suggestion for the second one , can i ask about manner of switching back and forth for monitoring .?I plan to look up your suggestion with broad band , but since I am here and just finished reading your post , why not get a first hand answer as well as what interpretation I get from my findings .?
sorry for not answering you question about rad(s).

That will be down the road abit , like I said in one of my earlier posts , I will just use a soft 90 degree rubber hose to connect : front end "of rad tubes ( which doubles as a beam under the car to mount struts that bolts to the motor mounts on each side at the back end of car .
I anticipated rad or rads at nose of car so had some louvres stamed into front hood to allow air to pass through freely and not just be a dead area for air behind rad .

I have had in mind a 4 core custom built rad with elec fan(s), probably overkill as there will be alot of coolant in 2times 10 feet by 2 by 3 in O/D tubing that will connect rad to engine .'
Maybe something right sized and newer out of a wrecker , and spend on some type of temperature based activation pump on the return end of rad to engine helping out water pump at engine ?
Probably best to hook up temperature gauge with numbers and monitor upon starting and running and dealing with this thing that i dont know even exists if temp warrants something more
I have seen posts about personal mail , but havent seen enabler on this website
piedrock@hotmail.com
As always , thank for your time and patience

 

[RonD]

Oh, yes, worked on lots of Fords and other brands, just never for Ford

Just swap the computer's O2 wiring harness plug from one O2 to the other, key off of course
Low tech is best, lol

I doubt you would need an external water pump, you are not lifting the coolant up, so its just for flow
But coolant is a "pound a pint" so 8lbs per gallon of coolant
Just adds to overall weight of vehicle

You would need a fan to push or pull air thru rad(s) when you are stopped
Temp sensors/senders need to be on the engine, you can add others on rad or hoses, but the engine temp is the BIG one, 4.0l WILL crack a head if its over heated, no maybe and no do overs, it WILL, lol