Stumbling 4.0


Braindead

Member
Joined
May 3, 2015
Messages
30
Reaction score
4
Points
8
Location
Burnaby BC Canada
Vehicle Year
84, 85, 94, 97
Make / Model
Rangers
Engine Size
8"electric, 2.3, 4.0-OHV, 4.0-OHV
My credo
They say it can't be done, so I did it. Again
My 97 4.0 RWD 5 speed Ranger had the transmission lock up a year ago and slid to a stop almost doing a complete 180 on a freeway on ramp. The truck has close to 400,000 km on it but looks, rides, and drives like it has one tenth that much.
I found a 5 speed from an '03 Ranger and installed it, and while doing the install, accidentally got the downstream O² wires crushed into oblivion between the block and bellhousing. (Which was correctly suggested by a Ranger Station member).
I soldered a new plug onto the what was left of the wires and because I happened to have one, I replaced the sensor.
At this point the speedometer is not functioning even though everything appears to be plugged in.
Before the wiring snafu was discovered, I tried driving it and at around 20 mph under any loads, light or heavy, it stumbles HARD ! It is almost violent if under hard acceleration but seems to run perfectly otherwise. It does not die, and it does not seem to matter what gear it is in or what the engine RPM is at, I cannot go any faster than about 20 mph.
Now the wiring is all in place as far as I can tell but the stumbling issue is still present.
It starts easy and idles just fine. Before the transmission broke, I never had this problem.
I doubt it has any bearing on the problem at hand, but it does have a problem with the throttle sticking wide open if I floor it and has done that since I bought it. It still happens even after I put on extra return springs, and nothing binding that I can see.
I need this truck on the road asap but I don't have a lot of money to throw at it.
35671
 


Rock Auto 5% Discount Code: CFB3B5F7F32B37 Expires: March 30, 2020

Josh B

Well-known member
Supporting Member
TRS 20th Anniversary
Joined
Aug 15, 2019
Messages
1,094
Reaction score
300
Points
83
Location
Oklahoma
Vehicle Year
1993
Make / Model
Ford Ranger
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
At one point while reading that I got the feeling it basically did the same thing both times
 

RonD

Well-known member
Joined
Jun 2, 2012
Messages
14,403
Reaction score
1,045
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Speedometer "may" be the issue, but clean the MAF sensor, always, when a 4.0l stumbles

OK, 2003 transmission(2001-2011) will have an OSS sensor not a VSS which is why speedo doesn't work, and there is no mechanical fix for that unless you want to swap in a 1990-1997 M5OD-R1 4.0l transmission

Best bet is to get a Dakota Digital SGI-5E interface, $85

Your 1997 used a VSS on the transmission with a gear drive, Ford speedometers expect an 8,000ppm(pulse per mile) signal which is what that VSS provided
The OSS is more like 20,000ppm, and in 2003 it's signal didn't go to speedometer, it went to the 2003 computer, the computer then converted it to 8,000ppm signal and sent it out to speedometer, and cruise

So the SGI-5E is needed to do this conversion
The SGI-5E needs to be located in the cab, and powered with key on 12volts
Best method would be to run 4 wires to the OSS/truck wires, since they are already hooked to speedo, cruise and computer
Then splice in the 4 wires to the trucks 2 wires so the signal comes out of the OSS runs to the SGI-5E then OUT of the SGI-5E and to the truck wires going into the harness

OSS=========SGI-5E=========Truck wires=========speedo/cruise/computer

The SGI-5E can then be adjusted to make speedo/odo accurate

Most hardware stores will have 4 conductor wire by the foot, 22-28gauge is fine, even data/tel wire would work
There are no amps, and maybe 3-5volts AC max


EDIT:
The 1990-1997 Rangers had a "drive" gear on the tail shaft that drove the speedometer "driven" gear which turned the speedo cable and VSS, until 1995, then the speedo cable was removed but the VSS stayed, in 1998 the tail shaft gear was removed, the rear axle ABS VSS was used and 1998-2000 GEM module converted that signal to 8,000ppm
Then in 2001 the tail shaft got a tone ring and an OSS sensor to read the tone ring pulses, and that was sent to the computer, which converted it to 8,000ppm
Now I have never looked at the tail shafts to see if the tone ring can be swapped out for the gear
The tail shafts could be swapped, although I think you would have to pull the trans to do that
The gear was removable from the 1990-1997 tail shafts, just not sure on the tone ring on 2001 and up
 
Last edited:

Braindead

Member
Joined
May 3, 2015
Messages
30
Reaction score
4
Points
8
Location
Burnaby BC Canada
Vehicle Year
84, 85, 94, 97
Make / Model
Rangers
Engine Size
8"electric, 2.3, 4.0-OHV, 4.0-OHV
My credo
They say it can't be done, so I did it. Again
Speedometer "may" be the issue, but clean the MAF sensor, always, when a 4.0l stumbles

OK, 2003 transmission(2001-2011) will have an OSS sensor not a VSS which is why speedo doesn't work, and there is no mechanical fix for that unless you want to swap in a 1990-1997 M5OD-R1 4.0l transmission

Best bet is to get a Dakota Digital SGI-5E interface, $85

Your 1997 used a VSS on the transmission with a gear drive, Ford speedometers expect an 8,000ppm(pulse per mile) signal which is what that VSS provided
The OSS is more like 20,000ppm, and in 2003 it's signal didn't go to speedometer, it went to the 2003 computer, the computer then converted it to 8,000ppm signal and sent it out to speedometer, and cruise

So the SGI-5E is needed to do this conversion
The SGI-5E needs to be located in the cab, and powered with key on 12volts
Best method would be to run 4 wires to the OSS/truck wires, since they are already hooked to speedo, cruise and computer
Then splice in the 4 wires to the trucks 2 wires so the signal comes out of the OSS runs to the SGI-5E then OUT of the SGI-5E and to the truck wires going into the harness

OSS=========SGI-5E=========Truck wires=========speedo/cruise/computer

The SGI-5E can then be adjusted to make speedo/odo accurate

Most hardware stores will have 4 conductor wire by the foot, 22-28gauge is fine, even data/tel wire would work
There are no amps, and maybe 3-5volts AC max


EDIT:
The 1990-1997 Rangers had a "drive" gear on the tail shaft that drove the speedometer "driven" gear which turned the speedo cable and VSS, until 1995, then the speedo cable was removed but the VSS stayed, in 1998 the tail shaft gear was removed, the rear axle ABS VSS was used and 1998-2000 GEM module converted that signal to 8,000ppm
Then in 2001 the tail shaft got a tone ring and an OSS sensor to read the tone ring pulses, and that was sent to the computer, which converted it to 8,000ppm
So the speedo could be at least a contributing factor, which I expected. MAF has been cleaned two or three times with correct cleaning spray in the manner indicated on the can. Then I bought a new one.
I found a retail outlet locally that has the digital interface in stock ($119 CDN) and I am debating if I am going to wade through rush hour on freezing snow and ice packed roads, or go tomorrow.
Snow WAS invented for having a blast driving in it, after all.
That is MY theory, and I stand by it.
 
Last edited by a moderator:

Braindead

Member
Joined
May 3, 2015
Messages
30
Reaction score
4
Points
8
Location
Burnaby BC Canada
Vehicle Year
84, 85, 94, 97
Make / Model
Rangers
Engine Size
8"electric, 2.3, 4.0-OHV, 4.0-OHV
My credo
They say it can't be done, so I did it. Again
Speedometer "may" be the issue, but clean the MAF sensor, always, when a 4.0l stumbles

OK, 2003 transmission(2001-2011) will have an OSS sensor not a VSS which is why speedo doesn't work, and there is no mechanical fix for that unless you want to swap in a 1990-1997 M5OD-R1 4.0l transmission

Best bet is to get a Dakota Digital SGI-5E interface, $85

Your 1997 used a VSS on the transmission with a gear drive, Ford speedometers expect an 8,000ppm(pulse per mile) signal which is what that VSS provided
The OSS is more like 20,000ppm, and in 2003 it's signal didn't go to speedometer, it went to the 2003 computer, the computer then converted it to 8,000ppm signal and sent it out to speedometer, and cruise

So the SGI-5E is needed to do this conversion
The SGI-5E needs to be located in the cab, and powered with key on 12volts
Best method would be to run 4 wires to the OSS/truck wires, since they are already hooked to speedo, cruise and computer
Then splice in the 4 wires to the trucks 2 wires so the signal comes out of the OSS runs to the SGI-5E then OUT of the SGI-5E and to the truck wires going into the harness

OSS=========SGI-5E=========Truck wires=========speedo/cruise/computer

The SGI-5E can then be adjusted to make speedo/odo accurate

Most hardware stores will have 4 conductor wire by the foot, 22-28gauge is fine, even data/tel wire would work
There are no amps, and maybe 3-5volts AC max


EDIT:
The 1990-1997 Rangers had a "drive" gear on the tail shaft that drove the speedometer "driven" gear which turned the speedo cable and VSS, until 1995, then the speedo cable was removed but the VSS stayed, in 1998 the tail shaft gear was removed, the rear axle ABS VSS was used and 1998-2000 GEM module converted that signal to 8,000ppm
Then in 2001 the tail shaft got a tone ring and an OSS sensor to read the tone ring pulses, and that was sent to the computer, which converted it to 8,000ppm
Now I have never looked at the tail shafts to see if the tone ring can be swapped out for the gear
The tail shafts could be swapped, although I think you would have to pull the trans to do that
The gear was removable from the 1990-1997 tail shafts, just not sure on the tone ring on 2001 and up
BTW, thanks for the input. I hope it is the final fix for this episode.
It's never easy !
 

Braindead

Member
Joined
May 3, 2015
Messages
30
Reaction score
4
Points
8
Location
Burnaby BC Canada
Vehicle Year
84, 85, 94, 97
Make / Model
Rangers
Engine Size
8"electric, 2.3, 4.0-OHV, 4.0-OHV
My credo
They say it can't be done, so I did it. Again
I just had a thought about the Dakota Digital interface and a possible problem. If it uses small gauge wires and is inside the cab I am thinking there may be cross-talk from the stereo system. Not from the low level signals as they are mostly sheathed, and they will be replaced with balanced cabling soon, but the speaker wiring is all through the cab, up to 8 AWG. I admit my math is pretty weak, but it seems the frequencies are not that far apart and with harmonics being taken into consideration there might be an issue of interference between the systems.
Is it imperative to have the interface in the interior ? Would a weatherproof container under the hood work I wonder ? I suppose I will have to contact the manufacturer .
 

RonD

Well-known member
Joined
Jun 2, 2012
Messages
14,403
Reaction score
1,045
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
No, shouldn't be an issue at all

Ford used the GEM module in 1998 to 2000 as the interface and its located next to the Radio and speaker wires

VR(variable reluctance) sensor signals are very robust, which is why ABS, crank, cam, and speed signals use them, and they don't, for the most part, used shielded wires, I have seen shielded pairs on crank and cam VR sensors but I think that is because they are in the engine bay so high voltage spark wiring could be an issue.

You can locate the interface anywhere you want but you do need to adjust it once its installed


Just as a heads up, one wire on the truck side of OSS/VSS hook up will be a ground, so when you cut the wires test which one is Grounded(truck side), should be the Pink/orange stripe wire
The VR sensor sends out an AC sine wave, so +/- voltage wave, the only part that is used is 0 to +peak volts, so only 1/2 the pulses are used
Grey/black stripe wire is the + wire
This is why the speedo, cruise, and computer just have the 1 grey/black wire hooked up for VSS signal IN, because these are already grounded to vehicle for the 0volt edge of the pulse, so they only need the + side pulse
 
Last edited:

Braindead

Member
Joined
May 3, 2015
Messages
30
Reaction score
4
Points
8
Location
Burnaby BC Canada
Vehicle Year
84, 85, 94, 97
Make / Model
Rangers
Engine Size
8"electric, 2.3, 4.0-OHV, 4.0-OHV
My credo
They say it can't be done, so I did it. Again
Speedometer "may" be the issue, but clean the MAF sensor, always, when a 4.0l stumbles

OK, 2003 transmission(2001-2011) will have an OSS sensor not a VSS which is why speedo doesn't work, and there is no mechanical fix for that unless you want to swap in a 1990-1997 M5OD-R1 4.0l transmission

Best bet is to get a Dakota Digital SGI-5E interface, $85

Your 1997 used a VSS on the transmission with a gear drive, Ford speedometers expect an 8,000ppm(pulse per mile) signal which is what that VSS provided
The OSS is more like 20,000ppm, and in 2003 it's signal didn't go to speedometer, it went to the 2003 computer, the computer then converted it to 8,000ppm signal and sent it out to speedometer, and cruise

So the SGI-5E is needed to do this conversion
The SGI-5E needs to be located in the cab, and powered with key on 12volts
Best method would be to run 4 wires to the OSS/truck wires, since they are already hooked to speedo, cruise and computer
Then splice in the 4 wires to the trucks 2 wires so the signal comes out of the OSS runs to the SGI-5E then OUT of the SGI-5E and to the truck wires going into the harness

OSS=========SGI-5E=========Truck wires=========speedo/cruise/computer

The SGI-5E can then be adjusted to make speedo/odo accurate

Most hardware stores will have 4 conductor wire by the foot, 22-28gauge is fine, even data/tel wire would work
There are no amps, and maybe 3-5volts AC max


EDIT:
The 1990-1997 Rangers had a "drive" gear on the tail shaft that drove the speedometer "driven" gear which turned the speedo cable and VSS, until 1995, then the speedo cable was removed but the VSS stayed, in 1998 the tail shaft gear was removed, the rear axle ABS VSS was used and 1998-2000 GEM module converted that signal to 8,000ppm
Then in 2001 the tail shaft got a tone ring and an OSS sensor to read the tone ring pulses, and that was sent to the computer, which converted it to 8,000ppm
Now I have never looked at the tail shafts to see if the tone ring can be swapped out for the gear
The tail shafts could be swapped, although I think you would have to pull the trans to do that
The gear was removable from the 1990-1997 tail shafts, just not sure on the tone ring on 2001 and up
According to the Dakota Digital website, "Do not use this unit to adjust a signal going to an anti-lock braking system ". My Ranger has an ABS light on the dashboard that lights up when started.
 

RonD

Well-known member
Joined
Jun 2, 2012
Messages
14,403
Reaction score
1,045
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Yes, that warning is correct, you shouldn't change the VSS sensor pulses going to ABS module
This is in regards to rear axle VSS or front wheel VSS for that matter

But you can use the pulses from the VSS/ABS sensor, splice into rear VSS sensor wires, to hook up an interface module for conversion to the 8,000ppm the speedo needs
This doesn't change the the pulses going to the ABS module just to speedo, cruise and computer

So you are sharing the rear axle VSS/ABS sensor, same as Ford did in 1998-2000 Rangers using the GEM module

But this has nothing to do with OSS or VSS on the transmission, thats not used or connected to the ABS system

So if you have an ABS light it could be the wires to the rear axle VSS sensor were effected by the transmission swap, check it
 


Top