98 explorer pcm tuning help newbie

[Snake0503]

ya he sent me a READ0 ADX file with data logging unfortunately it did not work for me. I could not get anything to read on the tuner pro rt dashboard.

ill double check continuity for the speed sensor to the pcm. it should be getting a signal as I just sliced into the vss/oss sensor on the tail shaft.

[BOOSTEDEVERYTHING]

The tail shaft isn’t the correct signal. I had to use the rear speed sensor I believe. I can’t remember what I did there. But it wasn’t a simple splice it into the tail shaft speed sensor. I’ll have to see if I made notes on what I had to do there.
Try and download the version that’s up now. It’s the same name, he just had to add or update something in the file. The first version he sent me didn’t work either.

I’ll try and verify that the new file does work when I get home this evening and let you know.

[Snake0503]

boosted you were correct! so when I spliced into the oss/vss on the tail shaft for my signal interface I also added a weather pack to the dark blue/yellow (OSS to PCM) and grey/red (signal return) which ran to the ecu for its speed signal and I did not have it plugged in all the way running to the ecu. plugged it in and the truck runs much better at low speed, light throttle. low speed response is better as well! big thanks.

according to my 98 explorer EVTM the ecu receives the speed signal from the 4WABS module which gets a 8000 pulse signal from the rear diff
but if the truck was equipped with a 5r55e auto transmission (which my expo had) it has a OSS sensor in the tail shaft same as a M5ODR2 which also generates a 8000 pulse signal, which runs straight to the PCM. so looking through my EVTM's there are multiple ways to do it I just did not want to tie in with the ABS system.

so really the only issue I have left is a high idle which I think I have an idea as to why. I believe the the idle is still set for an auto, and thinks its always in "park" or "neutral" which would explain the higher RPM. autos idle higher in park and neutral and drop down once in gear. so id have to have my idle in neutral and idle in drive to the same thing probably like 700-750 rpm with my cam. and adjust the the idle spark control? adjust my error rates. I can't see anything in tuner pro rt

[Snake0503]

tried the new file. still was not able to poll any data.

[ATPCR]

Glad to read y'all's breakdown on what you have done installing a 5.0 in a 1998 to 2011 coil spring 2wd Ranger. You're right, there is hardly any info for that 5.0 swap. That will be my 2nd c-n-p 5.0/4R70W swap which will be a 1999 2wd shorty Ranger. I could tell that the Explorer pan wouldn't work without some extra fab work. For now, I have a 1968 early Bronco 302 oil pan that is a rear sump design. The crossmember still may need a flat spot for it. The Ranger has the VSS at the differential and an Explorer rear end that I have has it too. I'll be using the 2003 PCM that Michael has strongly suggested. I look forward to the project after getting the Mountaineer on the road.
Keep up the good work, looking good.

[Snake0503]

hindsight being 20/20. if I knew then what I know now. id have gone with the 03 crown vic ecu and coil on plug, custom harness route as I did have to modify the explorer harness already quite a bit to work with the ranger

the VSS in the rearend is for the 4WABS I didn't want to slice into it as I had another source on the trans. but splicing into the rear VSS would work the same. I can confirm the 8.8 expo and 7.5 ranger share the same VSS plug and wiring.

in the next couple weeks when I have time I will be fabricating new down pipes as I don't like how low the LH side hangs as it crosses over to the RH side.

idle issue is resolved for now. TPS sensor was and throttle stop needed adjustment and I wasn't disconnecting the battery between adjustments.
idles pretty smooth at about 800 on the factory tach tho I suspect its actually probably lower 650-700.

[ATPCR]

@Snake0503 The tone ring/reluctor wheel on the 7.5 and Explorer 8.8 have different number of teeth. Something that I assume could be adjusted.
When I started my project summer of 2021, I had the harness and PCM from a 1999 Crown Vic. I wasn't aware of this site until ~ Feb 2023 which has all the information about how to do the conversions the best way. I ended up modifying the original '97 Explorer/Mountaineer harness that was only wired for 4 coil drivers. I was so focused on repurposing the 2 rear O2 sensor wires to make the the other 4 coil driver wires that it totally slipped by me that the '99 Crown Vic didn't even have a tachometer. Go figure. This Morning I looked in my 2003 Crown Victoria/Grand Marquis book and it does have the tach on pin 48. The '99 CV power train harness is going to get extensively modified to use in 5.0 #2 in a 1954 F100, using the 2003 PCM.
So far the Dakota Digital box is the only way that I found to make my '97 MM with the '99 CV PCM tachometer work. You would think that the tachometer provision would be inside that unit. I don't know though because I'm very much a rookie having to do with all of the Automotive Technician stuff.
I'm an old school Mechanic. 45 years ago the old school guys would call us new school mechanics because we were messing with 289s then 302s with Holleys and dual point distributors then in 1973 Duraspark came out and we ditched the dual point distributors that took weekly adjusting.

[Snake0503]

I think it would depend on the rear end ratio? I had 3.73/7.5 swapped for a 3.73/8.8 so I shouldn't need swapped over if I was running an older 4WABS set up. but I used a Dakota digital for my speedo. pretty simple to install and adjust. easily hid it behind the radio. id have to see the EVTM for the CV to know how it converts its speed signal. but I would suggest the Dakota digital for the speedo

I believe you would just have to tap into pin 48 on your ecu that is the tachometer pin for both my 98 ranger ecu and the 03 ranger ecu for what it's worth. burrow a pin from a spare ecu connector and pin it into yours then tie it in with the 42 pin connector in the engine bay. that'll send signal to your rangers tach or MM tach whatever cluster you decide to run they are interchangeable. EVTMs are a lifesaver

im in the same boat as you 60's SBFs and FEs, points etc (3 mustangs and an f100) my whole life so its been a slightly frustrating/ humbling experience with this build, as the problems I was having I know how to remedy them pretty easily with a vacuum gauge and a screw driver if I was running a carburetor and distributor. but its good to learn new things. while I feel like I'm on the cutting edge of automotive tech with this lol the kid I work with called my ranger "old school" so I am reminded this is dated tech now.

[ATPCR]

@Snake0503 Jegs calls the ring pressed on to the differential carrier an Abs Exciter Ring (Tone Ring). The 8.8 has 108 teeth, the 7.5 has 102 teeth.
I have cable driven speedometers for both the '97MM 5.0 (#1) and the 54 F100 5.0 (#2). For the '54 with a 1969 Cougar speedo and tach, I'll have to use an early 90's Mustang or F150 speedometer for cruise control to capture an electrical signal off of the transmission. I'm pretty sure that I will need the Dakota Digital box to make the antique tachometer function.
I would have to disconnect my 104 pin connector from the '97MM to see if I left the Explorer/Mountaineer pin # 48 wire in place. I assume that I did.
In my 1999 Crown Vic wiring book, at pin #48 says not used.
Dated, it depends on where one is looking at it from. My 17-year-old grandson would say that all of this is dated. He is not into automobiles. If he were, I would suggest that he start with a vehicle with a carburetor to learn the fundamentals about gas and spark. Changing jet sizes and reading plugs.
When we were ignorant teenagers, in the summer, our Holleys always ran rich. The local speed shop didn't suggest that we drop a jet size for our altitude. We are at 650 to 850 ft above sea level. We would drive down to the gulf coast and our home-built hotrods would run really well at sea level.
Holleys are factory tuned for sea level altitude @70 degrees F.
After looking at the 99CV book and the 97MM book, I'm sure that I would have left the tach wire in place. These are 99CV pics.

[Snake0503]

pin 48 isn't used on the CV as I don't believe CV's came with a tach option. but marauders did and they used pin 48 as well for the tach. so tapping into pin 48 should work. as the ecu's are fairly interchangeable with these models/years
(for our purposes) I could be wrong but decipha said any 4 door sedan CV, marauder etc would work for me.

I ran into a number of things that my evtm said were "there" but weren't especially on my ranger as it was a base model stick shift truck most things were blocked off and just not included in the harness. just means it wasn't used into your model but I believe it will still function if you did use it.

as for the ring sizes I would assume that's adjustable in the ecu.


haha ya the ignorance of youth.