Tuning Solution ford 91-94 4.0 OHV thanks to Paul Booth of EEC Editor Wideband instal

So after reading many threads on people looking for a tuning solution to the 91-94 Explorer ECU's. Some are buying preburnt chips claim to see improvements. From my past tuning history, you do need to read alot and understand the system. I am on track now to help with this tuning issue thanks to Paul Booth from EEC Editor. This is a great guy to work with. I emailed him with a question and in a matter of minutes we were coming up with new ways for tuning. This has been a great help, and anyone serious about improving their gas milage it always will start with spending a few dollars upfront to get a out come on the other side. I will be playing around with a stock BIN from a 92 X, ecu code T2Z1. I will see everything this has to offer and will report all findings. One of my next steps is to purchase a Quarter Horse which is a real time programming module that can be purchased from Moates.net. Working with Craig Moates or Paul Booth has been a blessing and there sites, and software is part of what took me to the next level in Honda/ Import Tuning. I will be trying other softwares as well, some are more user friendly than others, although I will leave that to you to decide. There is a ton of information out there on every thing else except the 91-94 explorer 4.0 OHV. My plan is to change that. Open doors for those who really want tuning solutions. I do recommend before even trying this, purchase a LC-1 wideband, the analog out put can be connected into pin 29 gry/light blue. You will need to to leave the heater circuit hooked up on stock O2 sensor just to keep from throughing the O2 code. This alone with a few upgrades as in electric fan, air intake should add a noticable difference in drive performance. I purchase my widebands from StreetRays out of Austin, TX for around $170. I will continue to work on my upgrade and will start posting pictures once I have completed them. Thanks again for your time reading this and props to Paul Booth at EEC Editor for the ongoing help.
http://www.moates.net/ will find tuning products and EEC Editor

Subscribing. I've been eyeing Tweecer for if/when I do a SOHC swap.

x3

I have a Innovative wideband o2 on one bank connected to an AFR meter and have contemplated going completely aftermarket but am not interested in playing that much.

There is a couple ways for tuning a first gen.all very expensive.the cheapest is the sct 5 bank chip.thats what I run and some others.BUT and big BUT for a stock motor you wont see any gains for the cost of tunning.only reason to tune a first gen is if its forced induction. First gens are just gas hogs and tuning isnt going to help.now if you had all the electronics of a OBD2 and a electronic trans then some gains are there, BUT first gens dont have that.spend the time and money on tune up, udp, efan and proper gears/tires.

Also on other forums they have been useing quaterhorse for awile and even have files your can download.

was there ever any progress made on this?

I went this path for my sohc conversion in my first gen. It is extremely expensive and complicated. But the problem I see with your plan is simple.

If your whole reason for doing this is gas mileage, why are you using a batch fire fuel injection computer. If you want to get better mileage out of a 91-93 OHV its simple switch to a 94 ecu witch uses SEFI. It will require rewiring the injectors and repining the ecu connector. but well worth it.

Edit: forgot to add you will have to add a cam position sensor and a big bonus is you get a second o2 sensor.

dblD1968 said:

I went this path for my sohc conversion in my first gen. It is extremely expensive and complicated. But the problem I see with your plan is simple.

If your whole reason for doing this is gas mileage, why are you using a batch fire fuel injection computer. If you want to get better mileage out of a 91-93 OHV its simple switch to a 94 ecu witch uses SEFI. It will require rewiring the injectors and repining the ecu connector. but well worth it.

Edit: forgot to add you will have to add a cam position sensor and a big bonus is you get a second o2 sensor.

Click to expand...

My '93 ranger (4.0L-OHV, 4x4, M5ROD) has (2) o2 sensors (L/R bank), and no CMP.

So, you are saying that simply switching to a '94 ecm will convert the fuel system to sequential injection, and make an improvement to fuel economy? How much improvement can be expected? EXACTLY what other changes are required? Can a CPS simply be plugged in where there wasn't one before? What about EGR? '94 would have EGR, where as my '93 does not. Will that have to be added as well?
How about some pics/diagrams of the required injector wiring changes and pin out changes?

Hi, Carguy3J
Here is your ECU(computer) wiring diagram.


Here is a 1994 ECU wiring diagram. (notice how the injector wiring changes)


The problem is Ford never put a CMP-camshaft position sensor (be careful CPS means crankshaft position sensor in ford lingo) on the rangers in these years (federal emissions) for some reason. I have yet to find out if the Ranger ECUs are capable of using SEFI(sequential fuel injection).

But if you want to switch to SEFI here is what I think you have to do,

Disclaimer:
(this is where I am at on my project so I do not have the data to confirm this, but from studying the wiring diagrams and the Ford documents this is what I have come up with. I will post a whole thread on my findings on one of the forums ((most likely this one since is has helped me the most)) when I finish my project. I keep with the same user name so it will be easy to find).



Ok the switch from EFI (batch fire fuel injection, basically this means each bank of injectors opens at the same time ((for 4.0L OHV CYL. 1,2,3 injectors open and inject fuel when #1 is on intake stroke. This means CYL. #2 and #3 have fuel just sitting around until they are back to the intake storke.)) I believe this is not a huge deal on high RPM but at idle and in town driving this would be completely wasteful.)


To SEFI (sequential Fuel Injection, this is what I am working to get and solve for us first gen guys! This would mean the injectors only open when each cylinder is on the intake stroke. I do not see how this would not be beneficial through out the whole RPM range but once again I do not own a dyno or have numbers to back this up).

Okay enough messing around as I am sure you already know all of this I just want to make sure we are on the same page when I explain this.





Here is what you have to do, once more there may be more to this I will be expand on it more as I go.

If you have a manual(standard) transmission (I have no idea about automatics since I do not play with those, but this should apply the same, you just might have to change the pins on your ECU, DO YOUR HOMEWORK OR YOU WILL FRY YOUR ECU) ranger or explorer that is a 4.0L OHV from 19xx to 1993 (1993 explorers are supposed to have a CMP but are not wired for SEFI, I do not get this as the only purpose for the CMP is SEFI confuses the heck out of me. Can some one explain that to me??)

But anyway back to the point, you need to find yourself a 1994 ECU from an explorer even if you have a Ranger.(If your vehicle is a manual find a manual fed emission ECU, or if you have an automatic find an automatic ECU. The Ford federal emission ECU for manual trans. part number is F47F-12A650-KA or F47F-12A650-KB).

Then after you find yourself the right ECU you will need to rewire your injectors(so each one goes to the ECU on the ground side they each have separate pins on the ECU), wire in a CMP to pin 33, and a second o2 sensor if you do not have one, you also can wire in a EGR vacuum regulator off of pin 24 if you want one, pin 60 an 40 coming off of the ECU now will be a combined ground I don't understand this yet?, and the MAF no longer grounds to the ECU.

So simply switching ECUs will not same you money on gas, it will fry your ECU. BUT if you go threw a little work I think it will improve your gas mileage quite a bit! As for the EGR like I said it is just a electronic controlled vacuum regulator that is connected to your ECU. That is a huge benefit!


One last time I have a 4.0L OHV but I am not using it, I went strait to the 4.0L SOHC with this system. I have no idea how much you will gain in fuel economy but it SHOULD be noticeable. So give it a shot! Go get yourself an extra harness out of the junk yard and give it a try! Then let us know how much money you are saving! In the mean time I will be doing the same thing but I am converting a 1991 harness to a 1994 harness (not worth it) for a stupid 4.0L SOHC for my stupid 1988 ranger and I will post my results.

I am sure I will need to add way more later as this is an extremely complex conversion, but this will get you thinking.

Edit #1 forgot 1994 wiring diagram.

So, couldn't I just avoid all the cutting/splicing, and just use a '94 Explorer ecm, AND engine wire harness? Or are there reasons that wouldn't work on the '93 Ranger?

As far as EGR, I don't think its "optional", if the ecm is expecting it to be there. Not having it present would likely set codes and the MIL light.

You could use a 1994 explorer engine harness it just might require some modifications where it connects to your body harness.

But since you are switching harness just grab the regulator when you are pulling it. It would send a code with out it.

Any progress?

Bump...I'm very interested in the progression of the project as well!

So whats the difference is a 90-93 explorer and a 93-94 ranger besides one has two O2s??? Can I just add a second O2 to my explorer and it work or do the 93-94 use a different computer?

But interesting I thought my 94 has sefi?? I need to point this out to my tuner..I certainly dont want feul sitting around..last thing I need is it to ignite or detonate.....

Aslo going through this trouble of swapping ecm and harness, would it not be easier to do a 95 ecm swap and get obd2??

dblD1968 said:

Hi, Carguy3J
Here is your ECU(computer) wiring diagram.

Here is a 1994 ECU wiring diagram. (notice how the injector wiring changes)

The problem is Ford never put a CMP-camshaft position sensor (be careful CPS means crankshaft position sensor in ford lingo) on the rangers in these years (federal emissions) for some reason. I have yet to find out if the Ranger ECUs are capable of using SEFI(sequential fuel injection).

But if you want to switch to SEFI here is what I think you have to do,

Disclaimer:
(this is where I am at on my project so I do not have the data to confirm this, but from studying the wiring diagrams and the Ford documents this is what I have come up with. I will post a whole thread on my findings on one of the forums ((most likely this one since is has helped me the most)) when I finish my project. I keep with the same user name so it will be easy to find).



Ok the switch from EFI (batch fire fuel injection, basically this means each bank of injectors opens at the same time ((for 4.0L OHV CYL. 1,2,3 injectors open and inject fuel when #1 is on intake stroke. This means CYL. #2 and #3 have fuel just sitting around until they are back to the intake storke.)) I believe this is not a huge deal on high RPM but at idle and in town driving this would be completely wasteful.)


To SEFI (sequential Fuel Injection, this is what I am working to get and solve for us first gen guys! This would mean the injectors only open when each cylinder is on the intake stroke. I do not see how this would not be beneficial through out the whole RPM range but once again I do not own a dyno or have numbers to back this up).

Okay enough messing around as I am sure you already know all of this I just want to make sure we are on the same page when I explain this.





Here is what you have to do, once more there may be more to this I will be expand on it more as I go.

If you have a manual(standard) transmission (I have no idea about automatics since I do not play with those, but this should apply the same, you just might have to change the pins on your ECU, DO YOUR HOMEWORK OR YOU WILL FRY YOUR ECU) ranger or explorer that is a 4.0L OHV from 19xx to 1993 (1993 explorers are supposed to have a CMP but are not wired for SEFI, I do not get this as the only purpose for the CMP is SEFI confuses the heck out of me. Can some one explain that to me??)

But anyway back to the point, you need to find yourself a 1994 ECU from an explorer even if you have a Ranger.(If your vehicle is a manual find a manual fed emission ECU, or if you have an automatic find an automatic ECU. The Ford federal emission ECU for manual trans. part number is F47F-12A650-KA or F47F-12A650-KB).

Then after you find yourself the right ECU you will need to rewire your injectors(so each one goes to the ECU on the ground side they each have separate pins on the ECU), wire in a CMP to pin 33, and a second o2 sensor if you do not have one, you also can wire in a EGR vacuum regulator off of pin 24 if you want one, pin 60 an 40 coming off of the ECU now will be a combined ground I don't understand this yet?, and the MAF no longer grounds to the ECU.


Edit #1 forgot 1994 wiring diagram.

Click to expand...

Cam shaft sensor appears to go to 24 and egr to 33...also the O2s both go to different pins.the shorting bar also needs to go to pin 29 not 44 any longer..sure if I look even closer I may find more.

JD,
I keep looking at this and thinking to myself that it seems so easy to just swap a computer and add an extra O2 sensor and CPS and away I go. From what I see here, it is as simple as that.
On the other hand, sometimes there are super simple fixes that make world of differences, why couldn't this one be one of them?!

malohnes said:

JD,
I keep looking at this and thinking to myself that it seems so easy to just swap a computer and add an extra O2 sensor and CPS and away I go. From what I see here, it is as simple as that.
On the other hand, sometimes there are super simple fixes that make world of differences, why couldn't this one be one of them?!

Click to expand...

I probably plan on doing this..I thought the 94 ranger was and so did my tuner..I certainly dont want fuel sitting around, especially in my new motor..

Im also looking into a piggy back obd2 95 system but pretty sure ill stick to making mine a sefi system. ..seems easy enough

My question is which injector is which on the explorer 94 system? ? Like cylinder one injector is pin number ** and cylinder 2 is pin **???

And side note im pretty sure the 94 explorer engine harness connects on the passenger side and ecm is in the passenger kick panel. .the rangers harness connects on the driverside and so is the ecm so you couldn't use the 94 ex engine harness on the rangers..

Good question JD. I think we should ask '94 Explorer owners to take a look at the color of the wiring on the injector harnesses and see what they are for each position. I can't see any way to ascertain which from the schematics.

Looks like you all ready did this JD. Thanks!

malohnes said:

Good question JD. I think we should ask '94 Explorer owners to take a look at the color of the wiring on the injector harnesses and see what they are for each position. I can't see any way to ascertain which from the schematics.

Looks like you all ready did this JD. Thanks!

Click to expand...

Yep...didnt wanna hijack this thread to much so started a knew thread. .I got pretty much it all figured out I """"""THINK"" and have a ecm on the way...anyone wanting to know more info see my thread..im 100% going through with this swap, hopefully next week or so, definitely before new motor


http://www.explorerforum.com/forums/showthread.php?p=3343384#post3343384