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'92 Custom w/ '95 MAF 5.0, 33's, 4.10 LSD
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Discussion Starter #1
I started in on re-pinning everything today, in advance of my '95 Cali Bronco MAF computer returning from servicing (burnt resistor, leaking capacitors) tomorrow. I have a handful of wire color mismatches that I'll finalize and post a summary of later, compiling several resources into one chart that may help others. I've got a few questions on the old '92 wires...

1) [Answered in post #6.] Where does Orange pin #49 (HEGO GND) go? All the cross walks show it only being for Speed Density. Do MAF trucks not ground the O2 sensor, or do they run the sensor directly to a chassis ground (or tee it into one of the eec grounds)?

http://www.fordtruckfanatics.com/forum/showthread.php?t=1624

MAF Conv. on Low Budget

"move O HEGO GND wire from pin 49 to splice with pin 46 signal return"

I think that second link answers the question, although the lack of clarity in the first link, and lack of coverage in general, leaves me a bit uncertain.

2) [Answered in post #2.] What is Purple pin #43 for? It doesn't show up on any of the charts...

Ironically, the first link above also raises that question and is the only thread I found mentioning it.

"According to some info I have and the diagrams on fordfuelinjection.com pin 43 on the trucks is a WOT AC clutch disconnect."

I have A/C removed, so if that info is correct, I can safely set aside the wire. I didn't find any other references to that wire/feature.

3) [Answered in post #3.] The lock tabs on the 60-pin EEC connector (E4LB-14489-C) are very brittle. Half of them broke from de-pinning... Are there any sources for replacement connectors? All I've found is one on ebay for $70, and it wouldn't surprise me if it's equally aged old stock. Seems kinda steep. I'll have to hope the terminals stay in place well enough in the meantime...getting all of them pushed into their slots is anything but fun...having to redo it all with a new connector will suck.

4a) Mostly answered in post #9. I know #45 LG/BK (MAP) is unused, but...

https://www.fullsizebronco.com/forum/7-1980-96-bronco-tech/171600-maf-swap-questions-using-rjm-harness.html

"Remove and plug the vacuum line from the MAP (Manifold Absolute Pressure) Sensor and seal any open vacuum ports on the Intake Manifold. Leave the Sensor plugged into the harness. Your MAP Sensor will now become a BP (Barometeric Pressure) Sensor."

How is it still working as a sensor if its wiring no longer connects to the computer?

4b) [Answered in post #5.] I assume #24 Y/GN (PSPS) also is unused? This one had me really puzzled in dissecting the '95 donor harness to separate out the MAF and injector pieces, as it had the PS pressure switch on it, but seemingly a dummy configuration that hooks into a mystery 2-pin round connector that's not on my '92 harness.

Referencing the engine harness connector's (square black piece next to the fuse box) numbering:

- mystery connector's red/yellow goes to terminal #10 and dark green/orange goes to #20.

- black/yellow (#36) tees into into dark green/orange (#20) and black (#9), and exits as black (splits to engine harness block and PSPS) and grey/white (PSPS) .

It's like they're just looped around to and through each other.
 

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3) I looked at 'mass-airexperts' other ebay listings and noticed they have the bare eec 60-pin connector for $29 under a different part # (CC-8693-F), which is much better than the $70 for the full kit. (Their prices for full MAF swaps are rather insane at $1590! But, they probably means they carry quality stuff.) Assuming I can figure out how to get the lock washer off the center bolt, the rest of the pieces in the kit don't do me any good.

Edit: I put the spare connector in a vise and hammered the threaded end of the bolt rather aggressively, and the lock ring finally popped loose. Also, the seller of the bare connector responded promptly saying it is an OEM item, despite the different brand listed and the part number that doesn't match mine.
 

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Discussion Starter #4 (Edited)

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4b) I always do my best thinking just as I'm falling asleep or just as I'm waking up...today was the latter. I got myself confused on the PSPS aspect by comparing the '95 engine harness (unusuable in full, due to two connectors being cut off, one other damaged, and lots of grease and sawdust caked up in the terminals) to my '92 engine bay. What I thought was my old PSPS wrapped up against the main wiring bundle was actually my old A/C connector!

So, that explains away PSPS still being on the '95 harness, and also partially explains the mysterious new connector on it. Did later year A/C compressors get a second connector of some sort?
 

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fodder,
this is awesome that you're assembling all of this valuable information.
for 4A) the "map" sensor is still plugged into the harness. Instead of the sensor "seeing" manifold pressure via a vacuum hose from the intake, it sounds like the sensor is now exposed to ambient or barometric pressure via the open port on the sensor which was previously connected to the previously mentioned vacuum tube from the intake.
 

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Discussion Starter #8
this is awesome that you're assembling all of this valuable information.
Thanks! (I was starting to wonder if I should ask a mod to move this to the parent forum...) I would have been totally lost without the road map laid out by others, so anything I can do to assist the next person is a no-brainer. Most of the info is 5+ years old, with miscellaneous gaps that couldn't hurt to fill in.

for 4A) the "map" sensor is still plugged into the harness. Instead of the sensor "seeing" manifold pressure via a vacuum hose from the intake, it sounds like the sensor is now exposed to ambient or barometric pressure via the open port on the sensor which was previously connected to the previously mentioned vacuum tube from the intake.
That would make sense, except the quote from the first post...

"Remove and plug the vacuum line from the MAP (Manifold Absolute Pressure) Sensor and seal any open vacuum ports on the Intake Manifold."

That sure sounds like the MAP sensor's vacuum port is to be capped.

Anyway, my new EEC 60-pin connector arrived today. I'm no fan of daylight savings, but especially not when USPS is on their periodic late schedule and there's only an hour of daylight left when they swing by... I moved all the wires over to the new connector and tidied things up enough to throw the freshly serviced TIP1 computer (VEX1 strategy) in, with the last two hours of work being by LED flood light.

It fired right up and produced no CELs! I quintuple checked every wire location, but still... I took it for a short spin and it for sure drove as good as before, and in lieu of a proper A-B comparison, seemed significantly better. Throttle response felt better, as often claimed, and acceleration might have been peppier.

The only weird thing is the 1-2 shift is very noticeable now. I wouldn't say harsh, but very abrupt. Is subtle abrupt a thing?? I'll have to do some research on that. I'm guessing the '95 Bronco the EEC came out of has some differences in how the computer controls the transmissions with the various improvements in the later years.

A couple random things to add: For drilling out the back plates for new MAF/injector wires, I found 1/8" to be the best size. For the big corner wires on the engine harness block, 11/64" is what you want. I opted to use the '95 connector's EEC back plate so I wouldn't have to carefully drill out the holes and plugs, but that meant re-pinning everything (I figured re-pinning 25% of them for the changes would be just as problematic with broken lock tabs, and drilling them out would take more time than re-pinning them all), so it's six of one, half dozen of the other as to which is better... My '95 engine harness back plates were in too poor of condition to reuse, so I drilled out a spare set.

Oh, and if 'mass-airexperts' is reading this, or for anyone shopping for a new 60-pin EEC connector, since they're the only place I found selling them...I would like to publicly apologize to them for being somewhat rude and accusatory via email. They charge quite a premium for expedited shipping (no economy option), but don't communicate post-sale to indicate it has been shipped or with the tracking number (automated steps with eBay sales; you almost have to intentionally mess up the process for that to not be sent out), so I was getting pretty impatient thinking I'd have to wait a week and be stuck with wet weather to re-pin everything. I honestly don't think they care, as they didn't respond to my private apology or suggestions for improving their communication, but I just wanted to put it out there for anyone wondering if the product is indeed OEM (not advertised as such) or how fast it'll arrive.
 

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Discussion Starter #9
4a) Wow, no wonder the explanations were so confusing, it's a different answer for every PCM application!

https://www.fullsizebronco.com/forum/7-1980-96-bronco-tech/196630-mass-air-coversion-my-92-a-9.html

"MAP sensor. Earlier in the thread there was a quick discussion about the MAP sensor being no longer needed in the MAF application, but nothing else. It's my understanding that in a MAF system the MAP sensor is absolutely needed, except that it functions as a Barometric Pressure sensor instead. All you have to do is disconnect the vacuum line from the manifold (where the port should be capped) to the BP/MAP sensor (where the port is left open to atmosphere). Not sure if this is what you did, but if not, take a look at this."

"Unless I'm missing a part which it possible, I was under the impression that the MAF system doesn't have a separate MAP sensor like the old SD system. When I removed my MAP sensor, I simply capped off the area on the vacuum tree where the line went. Am I missing something?"

"you need to leave map sensor plugged into harness with vac line removed."

"you need to leave map sensor plugged into harness with vac line removed and the hole for vacuum line capped."

"Just to clarify, I have the entire harness from a '95 MAF rig. There is no provision for a MAP sensor on that harness all I did was remove my old MAP sensor and block off the open port on the vacuum tree."

"you need to reconnect the MAP sensor to the harness/ECU, but leave the vacuum port on it open to atmosphere. It's purpose it to provide the ECU with the current barometric pressure of the atmosphere you're driving in, allowing it to properly adjust the air/fuel mixture."

"The 95 has a very similar sensor to the map sensor called the bap sensor I think that is what the others are speaking of."

"No BAP/MAP on the truck MAF setups. There's a nifty function in the PCM's programming that infers it from other data."

"You're right, the WAY1 doesn't need a BAP. My bad. My AKC0 (which is also a 1995+ EEC) needs one. Go figure.."

---

I'm assuming my TIP1 PCM behaves the same (it seems happy with the MAP vacuum barb capped), but there's another partial 5.0L MAF Bronco nearby I can look at to see what, if anything, it has mounted above the heater box. That could give me a hint. If there's nothing there, then the confusion over how the MAP sensor does anything with its input to the PCM (LG/BK, pin #45) omitted would be most likely put to rest. I may do an experiment with it unplugged and see if anything changes.

Also from that page, I see I need to look into push-start vs CCD TFI modules... That explains the Y/BK EEC pin#4 color discrepancy, but I don't know what the downside of running the old module would be. Edit: I found this on the last page..."I also had a pinging problem after upgrade which was due to a needed TFI ICM CCD upgrade."
 

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I did the MAF conversion on a 95 5.8 last year. I had a complete kit because I am too lazy to scrounge junkyards (plus I live in the middle of nowhere that doesn't have any JY's) The instructions I had showed to just remove the MAP hose, cap the intake connection and leave the one on the firewall open.
 

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Discussion Starter #11
I did the MAF conversion on a 95 5.8 last year. I had a complete kit because I am too lazy to scrounge junkyards (plus I live in the middle of nowhere that doesn't have any JY's) The instructions I had showed to just remove the MAP hose, cap the intake connection and leave the one on the firewall open.
That reads like three things. :) Rearranging the last sentence to what I think you mean..."The instructions I had showed to just remove and cap the MAP hose at the intake, and leave the one on the sensor open."

Out of curiosity, what kit did you go with? In my case, doing it the hard way made the most sense. I had bought much of my interior stuff from a '95 at the JY while troubleshooting the engine that turned out to be blown. In calling around for a replacement engine, they had a nice one that unexpectedly came from that same Bronco. While they were getting it out of the warehouse, I went down to look at what was left of the wiring harness, in case it might come in handy. To my surprise, it was a MAF truck, with PCM, MAF sensor, K&N intake tube, and most of the wiring still there! So, I've been running half a MAF setup all along, just putting it off while waiting on the verdict on the condition of the PCM.

I got the gray TFI module swapped out for the proper black one last night. I removed the Y/BK wire from the '95 donor harness (took a matter of seconds, already being de-pinned at the EEC end, and 90% unwrapped at the other end), so it should have been a quick job of just pulling the 60-pin connector off and removing the red lock tab protector...I worked on that stupid thing for an hour. I was putting so much force on it, I was getting worried I would break the connector neck of the PCM and the 60-pin connector. I finally came up with a thick pry tool to wedge in there and wiggle the connector free. That new connector sealed itself on like nobody's business. I guess it's water-tight!

Can't say I noticed any difference in driveability after that, although the first test (gray TFI) was just around the neighborhood at 25-40 mph. With the black TFI, I took it up to 65 mph, which is where the old TFI module might have produced pinging. The one negative is, the hard 1-2 shift isn't limited to 1-2, that's just the most noticeable. I found Stang's thread -- I had seen it referenced as Stangmata's and couldn't find anything matching that -- on E40D troubleshooting:

https://www.fullsizebronco.com/forum/23-technical-write-ups/364682-e4od-diagnosis-thread.html

I'm getting a hard shift from 1st to 2nd

This is called "safe mode" also referred to as limp mode. The transmission is essentially protecting itself from any further damage you may cause. The transmission is forcing itself to shift using pressure rather than the shift solenoids. Be aware that this is normal when there is a problem and you should continue with your diagnosis.
Damn, looks like I have more investigation to do. Hopefully, it's just something with the wiring and not an incompatibility between PCM and tranny. I've never paid too much attention to when it shifts, but last night I noted:

hard acceleration: 1-2 @ 1500, 2-3 @ 3000, 3-4 @ 2500 rpm
mild acceleration: 1-2 @ 2000, 2-3 @ 2500 rpm

When cruising, it tends to have a harsh downshift/skip (like rear end hop) around 40 mph. However, Reverse seems better, rolling back on its own now without having to give it gas. I'm guessing the Reverse solenoid is bad and bypassing it is an improvement.
 

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That's a good general resource, but it looks like more perpetuation of misinformation to me. Without knowing what PCM that kit uses, who knows if that info is even applicable. I think it's mostly carryover from many people using the Mustang MAF computers.

I feel like I'm in crazy world on this topic, with seemingly no one else asking how the MAP is still a functional sensor... Ignore for the time being the stuff I quoted in post #9 about there being no BAP/MAP on truck MAF setups.

The MAP only has 3 wires: GN/BK (disconnected from PCM), BK/W, GY/R (SIG RTN, aka GND). I'm guessing BK/W is power, despite that usually being a ground color? How can it possibly have any functional role with GN/BK disconnected?! If there were a 4th wire, I could see it maybe sending a signal elsewhere, but the sensor is just energized and ignored with a truck MAF computer.
 

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Re: the hard shifting, I pulled codes this morning and the only one is 625 = Electronic Pressure Control solenoid circuit fault (or Hard Fault), which would be input #38 to the PCM, i.e., tranny related. The diagnostic steps look somewhat daunting, so hopefully it's just a bad connection on that pin that can be seated better...
 

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Are you running a Punisher Valve body ? I have seen the prob. The EPC value can be tuned down 20% before you damage anything. I use Core Tuning software
 

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Are you running a Punisher Valve body ? I have seen the prob. The EPC value can be tuned down 20% before you damage anything. I use Core Tuning software
Not that I know of -- if I do, the original PCM was smoothing it out somehow -- but I was reading up on that and related stuff late last night. I was going to start a separate thread for that, but since you brought it up and most of the relevant info is already here...

Re: KOEO test: 625 = Electronic Pressure Control solenoid circuit fault. That's the W/Y #38 input to the PCM, so I checked against the old '95 donor harness and was surprised to see that that wire is one of the two (the other being Red V-PWR) that had empty vampire taps left behind. I wasn't reusing those wires (just MAF, TFI, and injectors), so didn't bother trying to figure out what purpose that might have served. I assumed the V-PWR tap was for running some other accessory off of ignition power, but I didn't look to see what the W/Y wire went to.

https://www.fullsizebronco.com/forum/7-1980-96-bronco-tech/124520-e4od-adjustable-pressure-riser-electric-shift-kit.html

That's awfully suspicious! The two wires that had taps on them are the two that the resistor mod employs to fool the EPC into raising line pressure and firming up shifts...which is exactly what I've got going on along with the EPC 625 code. The donor harness had them tapped right by the PCM instead of down by the tranny connector as is the norm, but it doesn't sound like it matters where along the V-PWR line(s) the resistor gets added, as far as affecting V-PWR itself.

What doesn't make sense, though, is I have the symptoms of the resistor mod on the '92 with no such mod (and no such behavior before the upgrades), when using the PCM from the '95 that appears to have removed the mod. It seems like a huge coincidence for wiring on only that input to have gotten disturbed -- it's raining like crazy, which makes wiring work not so great, but I do plan to check that #38 W/Y is well seated in the new EEC-IV connector -- but my only other explanation is that there's something else done to the PCM to replicate the mod? I haven't ran across any mods of the sort, and the J3 port still has the protective white paste on the board, so I don't think it was ever hooked up to a tuner...

Aside: Did the resistor mod fall out of favor 10 years ago? Did anyone end up frying their trannys from the higher line pressure (thePunisher wasn't too keen on it, in the link above), or was SigEPBlue proven right that it prolongs the life by not slipping the shifts?

I've got the troubleshooting stuff to go through if the PCM idea is a dead end...

https://www.fullsizebronco.com/forum/7-1980-96-bronco-tech/199552-pulled-code-625-a.html
 

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Yeah, it was three things and your interpretation is spot on. I used fiveology racing and it's ok but pricey.

I have the punisher valve body in my E4OD as well and tuned my line pressure down. I'm have my Bronco remote tuned this Friday so I can finalize the numbers and all....I'll post it when we are done.
 

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Discussion Starter #18 (Edited)
^ Remote tuning sounds fun, like paying a hacker to stress test your network!

I spoke with tcinu2 the other day about the wannabe shift kit behavior. He's thinking there could be an issue with my '95 PCM looking for F5 valve bodies but seeing F2 (?) on the '92 E40D. He was tight for time, so we didn't get into too much detail there. Anyone have experience with that? I would think it would be an issue for anyone doing a MAF conversion with a '94-95 PCM, but maybe the much rarer [than F150] Bronco MAF PCM's are the only ones tripped up by it?

The W/Y #38 input to the PCM, and the PCM's pin, look fine.

My MLPS looks like it's already been updated to the new style, but it's grungy enough to be worth replacing the sensor still.
 

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Discussion Starter #19
For anyone still skeptical, here's what a 1995 MAF Bronco has in the usual MAP sensor's place:



Nadda! Which is also the difference it makes with the MAP sensor's vacuum port plugged or open... The only reason to keep the sensor around, IMO, is to keep the power wire safe and sound.
 

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I ran across this yesterday:

https://www.fullsizebronco.com/forum/1570172-post18.html

Pic #12 shows my '95 donor harness "4b" mystery 2nd A/C connector (prev pic is titled "Disconnect the wires going to the AC") on a '96.

Also, I filled up after the MAF conversion and hit 40.0 miles (typical driving mix) as I was pulling up the driveway today, with the needle not quite down to the Full mark. I was only getting around 10 mpg before, even on easy highway driving -- I don't recall what I'd hit before dropping to 'Full', but I doubt it was more than 20-30 miles -- so that has me optimistic that the economy increase is more than anticipated. Still way too early to tell, though.

I still haven't done anything about the transmission limp mode, aka, free shift kit.
 
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