i hear the 2wd and 4x4 computers are the same,but ford says no.whats the deal?

rickcdewitt · Dec 5, 2007

i just got the box with everything i need to swap to a 4.0l.i called a local dealership to see if the computer was indeed for a 1992 ranger 5 speed.its part #f27f-12a650-jc.the guy said yes but that they used another part # for the 4x4 f27f-12a650-kc.
i'm putting this stuff in my 91 2.9l/fm-146/1354 manual shift truck and was wondering if anyone knows what the consequences of the 2wd CPU is?

MAKG · Dec 5, 2007

Might be calibration. Or might be NOTHING. There are two different sets of numbers for Ford computers. I think one is the part number and one is the calibration. They look similar.

The factory also supersedes some parts with updated ones (e.g., to service TSBs or to retire older seldom-used parts).

No one is going to check calibration codes, but the specs will go with the one the truck came with from the factory. Which means a probable idle speed failure because automatic vs. manual transmissions don't have the same idle speeds. The way around that is a retrofit sticker on the doorpost. Call the BAR. Note that they generally frown on retrofits from CA to non-CA emissions, for obvious reasons. You need this anyway for the 4.0L retrofit. You'll have to justify it, but it shouldn't be too hard since your new configuration did come from the factory.

On a 1992, the PCM doesn't know anything AT ALL about 4WD.

rickcdewitt · Dec 5, 2007

MAKG said:
Might be calibration. Or might be NOTHING.

No one is going to check calibration codes, but the specs will go with the one the truck came with from the factory. Which means a probable idle speed failure because automatic vs. manual transmissions don't have the same idle speeds.

On a 1992, the PCM doesn't know anything AT ALL about 4WD.

yes, damn calibration.if there is no auto to manual swap woulden't it pass?the parts guy at the dealer said that other stuff is calibration specific.he diden't say but i guess the MAF or IAC?could that have a signifigant impact on the smog levels?last question,in other words the cpu has nothing to do with the transfer case or the lights on the dash right?

rickcdewitt · Dec 6, 2007

i don't need to worry about smog now. i don't need to do that untill i sell it or move to another county or state.i'm just wondering what stuff isen't going to run right together(smog legal or not)

MAKG · Dec 6, 2007

Umm, is this the first vehicle you've ever owned?

You have to sniff your vehicle every two years, starting at the date of initial sale. Which means possibly as early as September of next year for a 1991.

rickcdewitt · Dec 6, 2007

MAKG said:
Umm, is this the first vehicle you've ever owned?

You have to sniff your vehicle every two years, starting at the date of initial sale. Which means possibly as early as September of next year for a 1991.

unless there was a new state law passed this year,you are wrong.in mendocino county and others in california you DO NOT NEED TO SMOG your vehicle at regular intervals.that will give me plenty of time to get it running for now,and find the right parts so the nearest smog rep. in santa rosa can legalize it later.no need to be rude,i have access to a smog machine in exchange for beer so i'm confident i can get something to work and pass a visual inspection.i'm no genius but i have a few ase's under my belt.don't be condesending,that doesn't answer my questions.i remember one of you mods saying if you don't know the answer to a question the best answer is no answer at all :thefinger:

.
nobodies swapped around the MAF or other parts between trucks with different calibrations?

AllanD · Dec 6, 2007

I'm relatively lucky in that I don't have to pass either a "sniff" or a visual.

But even if I did my conversion would pass and pass easily,
because everything in my 1987 is from a 1993 Explorer donor
and I do mean everything....

There is one thing as certain as death and taxes and that is laziness.
People don't get paid enough to check every "i", "t" and "j", so they don't bother
unless something is so obvious it jumps out and bites them on the nose.

And don't tell me it's different in California because there is no difference
in human nature between Homo Sapiens 48ius and Homo Sapiens Californius

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rickcdewitt · Dec 6, 2007

AllanD said:
I'm relatively lucky in that I don't have to pass either a "sniff" or a visual.

But even if I did my conversion would pass and pass easily,
because everything in my 1987 is from a 1993 Explorer donor
and I do mean everything....

There is one thing as certain as death and taxes and that is laziness.
People don't get paid enough to check every "i", "t" and "j", so they don't bother
unless something is so obvious it jumps out and bites them on the nose.

And don't tell me it's different in California because there is no difference
in human nature between Homo Sapiens 48ius and Homo Sapiens Californius

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my sentiments exactly,at a later date i will find a truck with all the cali spec stuff(comp,etc) and get it all so the calibration works.or i might just play around with what i have until it passes the sniffer.

AllanD · Dec 6, 2007

What cracks me up was in NJ they insist on removing your gas cap to verify you have an unleaded nosle restrictor in your fuel filler...

I asked why since leaded fuel is no longer sold ANYWHERE...

Never did get an intelligent answer but then again I asn't really expecting one either.

Mind you, NJ has mirrored Cali regulations like several other states have.
But like all states things are still hopelessly screwed up.

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MAKG · Dec 6, 2007

Allan, California hasn't inspected fuel restrictors for decades.

They do remove your fuel cap, but that's to check the evaporative emissions system, NOT for any restrictor.

rickcdewitt · Dec 6, 2007

whatever we have to go through its a good thing though.my grandpa used to tell me stories about the presmog era san francisco bay area and down south where there were thick brown clouds hanging in the sky every day.some places are still bad but its cleaned up some places at least.

MAKG · Dec 7, 2007

San Francisco itself never had an air quality problem, because of its location on a peninsula.

San Jose did. Oakland sorta did. So did Sacramento.

No part of California has worse air now than in the 70's. The Central Valley hasn't improved as much (and has grown substantially), so it's in the news more frequently. And its air quality isn't driven by industry and transportation like things were in the 70s -- it's agriculture in a dry environment, especially cow poop (including fertilizer).

rickcdewitt · Dec 7, 2007

MAKG said:
San Francisco itself never had an air quality problem, because of its location on a peninsula.

San Jose did. Oakland sorta did. So did Sacramento.

No part of California has worse air now than in the 70's. The Central Valley hasn't improved as much (and has grown substantially), so it's in the news more frequently. And its air quality isn't driven by industry and transportation like things were in the 70s -- it's agriculture in a dry environment, especially cow poop (including fertilizer).

my grandpa lived above a hot rod shop in oakland next to the mothers cookies factory for years in oakland and went all over the country restoring and redecorating theaters.he said the inland flowing ocean breeze trapped the smog in the bay(he never did say what part exactly) from the 50's until they started using effective smog controls(70's?).so you have had to smog every 2 years down in so-cal for about 20 years?bummer!you don't know anything about what components are affected by a given calibration(92 2wd ranger cpu) do you?or what parts absolutely can't be interchanged?i've got 91 exploder and 92 ranger stuff.

MAKG · Dec 7, 2007

No, I don't know the details, but the sensors are quite likely to be exactly the same. They tend to be VERY simple, and identical in operation even widely across vehicle lines and manufacturers. If it works AT ALL (which it will if done correctly), it will probably work just the same, with a couple of exceptions, generally involving which sensors and actuators are installed on the vehicle.

These exceptions might be:
1. Presence or absence of EGR or other emissions equipment, or
2. Presence or absence of a knock sensor.

I don't think either of those changed between 1991 and 1992.

Most "different" sensors differ in their physical packaging -- thread sizes and electrical connectors, for instance.

Since you are swapping from a 2.9L, you have one MAJOR difference -- almost all 2.9Ls are so-called "speed density" systems. Which means your donor has a MAF sensor and your truck has a MAP sensor. VERY different.

Almost all of the calibration lives in the PCM. It's things like what the timing curve is, when the EGR should be open, what throttle position corresponds to WOT, and so on.

Having said all that, the easiest and most reliable way to do this swap is to use the entire emissions system from the donor. From the airbox to the catalytic converter, and including the computer and computer harness.

AllanD · Dec 7, 2007

Actually some of the early 4.0's had a MAP too, though why I couldn't tell you.

I know my '93 didn't

I know my brother's '1990 Ranger 4.0 did.

Where in between that they dropped it...?

BTW, ONE MORE TIME!!!

the IMPORTANT information on the computer is NOT that
Long Ford part number...

The important information is either the three of four character code in the "box" at the top right side of the label, OR on some labels it's top center above the bar code.

In either case this "code" is in 1/4" tall letters so you have to worlk pretty damned hard to ignore it and read the nearly meaningless computer P/N which are typically 1/8" letters.

The PN gives you profound information, like it's a 1992 part, that it's for a "truck" and that it's a computer assembly, but the IMPORTANT information is all about that three or four digit code.

for example a 1992 Explorer 5sp would be "X2X2", while a 1993 (49state) will be "ANY1" (really, no joke) and a 1994 (post 01/10/94) would be "YAM1" and a 1996 Ranger "SEE2".

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i hear the 2wd and 4x4 computers are the same,but ford says no.whats the deal?

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