TJ de-computerization help
- Thread starter burtpenguinnn
- Start date
That's something people don't understand about old vehicles, and why any decently cared for modern OBDII vehicle can easily last 250K plus miles. If you talk to older people, they'll tell you that cars from the '60-80s, you started looking to off load them around 80,000 miles because they were generally worn out and starting to need major work. Fuel injection and OBDII really took care of most of the causes like fuel washing and routine maintenance intervals.
So, you have all the tools to fix everything else except the PCM on the spot, right? Crack a head? Throw a rod? Grenade a diff? Snap an axel? Break a window? How are any of these problems any less inconvenient than going to the post office, putting your PCM in a flat rate box and waiting a week or less?
In my experience with Jeeps (and most modern vehicles in general), mechanical parts start to wear out / break long before the PCM ever would / does. It should be the least of your inconvenience worries.
Yeah yeah 05-06 PCM failures blah blah blah. Known issue. Problem solved. I would argue that the PCM is one of the more robust components in our TJ's. Can they fail? Yes, but so can every other part without warning, and that alone should not be the determining factor.
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Sell the TJ. Take the extra 4k. Buy a CJ7 that is not destroyed. Throw a Weber off road carb on it and a DUI distributor. No more “computers”. No using your smart phone in the CJ though. No computers. No Skynet.
The CJ must have a draw bar with a desert water bag on the front and a Warn 8274. Then you’ll be living in the past like a boss.
At least you’ll will learn what the term “carburetor things” comes from in the proper rig. Such as flooding, no start, broken choke, cold start issues. Trust me I know the carb types. Just do in an old proper carb rig.
The CJ must have a draw bar with a desert water bag on the front and a Warn 8274. Then you’ll be living in the past like a boss.
At least you’ll will learn what the term “carburetor things” comes from in the proper rig. Such as flooding, no start, broken choke, cold start issues. Trust me I know the carb types. Just do in an old proper carb rig.
You and I will start at the same time. I'll have the PCM swapped out before you can get the spare tire off of the rear carrier. You also missed my point, you don't send it off to get it fixed until after you swap in the spare. Just like you don't fix a flat until you swap on the spare tire off of the back.
True, but I can also get a tire from any one of a zillion places all over the country, and tires aren't specific to a certain year range of TJ. And every car on the road needs tires and will need tires for the foreseeable future, so there is no pressing need to engineer a solution to overcome a world where TJ tires become less and less available. It's fundamentally different from a TJ-specific part that has been out of production for 20+ years.
Plus OP could always go get that tank tread thing that cycles around FB every so often.
Perhaps, which is why I'm not going down this road with OP. But I don't believe his reasoning is quite as invalid as many seem to think. I just land on a different side of the risk/reward calculation here. Whatevs, we don't all have to agree.
Guessing you know where I can buy a couple sets of Goodyear MTR in 35-12.50-17 then??
It isn't any more fundamentally different than any other specific hard to source part that any of us acquire to have when needed and that's the whole point.
I get the same question near daily, what's gonna happen if you no longer have brake pads for sale? Well, if you are that fucking worried about it, don't make it my fault or responsibility, buy a couple sets and throw them on the shelf. It not like they expire or go bad.
But, I guess that is a fundamental difference between us who have played hard offroad and have spares for shit that we break. It is our mindset, not an issue, we know how to deal with it and we don't let the lack of ready availability stop our recreation.
You can get the 4.2 cj 2 barrel carb to fit the 4.0 intake, install a dui cj distributor, and then a low pressure fuel pump, 904 or 727 trans from either a old full size Cherokee or cj, and all of the linkage with a 98-02 shifter. Cj dash with the old gauges and painless wiring… and the cj steering column.
Unfortunately everyone sucking on the pipe resulted in the generation that doesn't know how to tune carbs.
I can't shoe a horse either. Don't care. Don't need to know. That's not how I travel.
OP
at least my perfectly mechanically sound car wont shut down when the computer stops working when everything else is fine mechanically and it could run if it wasnt for the limitations imposed by the computer.
its a gamble
the chances of your TJs computer breaking is extremely low, but that kind of issue that it creates shouldnt even be an issue in the first place.
This is where I don’t understand your line of thought. Mechanical things fail, actually they fail way more often then the computer. Also the computer makes those mechanical things either not needed or allows them to last longer and more efficient.
The chances of being stranded are way higher with a mechanical part. Would you replace your starter with a hand crank?
I’m all for having a simple system, but the TJ is in the sweet spot for having enough tech to make it efficient but not enough tech to make it worse.
As I said most of my jeep knowledge started with CJ’s, I was a diehard CJ guy, loved their looks and simplicity. As soon as I got my hands on a TJ there was no looking back. If I ever build a CJ again, 100% I’ll swap it with a modern engine with will be managed by a computer.
It’s like you have some romantic fantasy about having a simple jeep, but go drive a couple before you lock yourself into this idea. You are giving up so much performance, efficiencies, reliability by going without a computer, and what comes with it.
I like where you’re coming from and trying to get to but, over the many years of owning and repairing all sorts of engines small to very large one thing I know for sure is I many more breakdowns and repairs with my older “non-computerized “ engines. As many have said tuning a carb is easy enough but f you know how but i really get tired of it. Just had the carb off my neighbors ‘74 cub cadet again. I did sell it to him so I’m stuck with its maintenance.
Get the CJ. Build it and enjoy it. But i recommend ya keep the tj sp you have something to drive regularly. My $.02
This thread is reminding me that when my '76 Trans Am is closer to done I really want to toss the carb and go EFI on that Pontiac 400.
By your own admission, you have no experience here. I can tell you this much, I've driven around a combined 1,000,000 miles with 4 vehicles now, all OBDII, and I have never replaced an ECU/PCM computer. Actually, 3 of those are/were Hondas and all I've had to replace above general maintenance was 1 radiator, 1 starter and 1 engine mount. I have also driven around 100,000 miles with a few "classic" cars with points and carbs. Much more prone to general maintenance and minor repairs, and today's gas will take out a carb in a hurry. I've rebuilt or replaced 3 over the last 15 years. But those are my toys that I enjoy, which is why I continue to live with them.
Go buy a relatively stock CJ7 and with some miles and time you will become good at parking lot repairs, especially with today's replacement parts. When my buddies and I were driving our old cars frequently, I was pretty good at diagnosing and repairing on the road.
Na, don't be a quitter. They're fine for old toys, just not modern vehicles.
Also, if you do toss that old original Quad, I'm here to catch it.
As I stated previous, I know I won't change your mind but the statement I fixed for you can apply to an astoundingly wide array of parts in your TJ.
You can replace the word computer with any of the following and it will be the same level of true.
Battery
Any part of the electrical system
Any of 50 bearings
U-joints causing catastrophic failure
T-case or any of the 100 parts inside that are so stupid simple and durable that they don't break, but they do.
Steering gear sector shaft
Steering shaft u-joint
Diffs
Axle shafts
ETC.!!!
The list of parts that can fail and don't except on a very rare basis is very large. The only difference is, they are not as easy to carry spares for and repair in the field as the PCM is with the exception of a few fuses and relays.
Isn’t a distributor a simple form of analog computer? Does that mean it has to go?
Jokes aside, perhaps a full diesel swap with one of the really old-style engines could work. If you ever visit the Green Bank Telescope (formerly part of the National Radio Astronomy Observatory), they only use old diesels because the spark of ordinary engines causes interference that can be picked up by the telescope. Hard to find aliens when some idiot is mowing their lawn with a gas mower and sparking up an EMI storm…
Jokes aside, perhaps a full diesel swap with one of the really old-style engines could work. If you ever visit the Green Bank Telescope (formerly part of the National Radio Astronomy Observatory), they only use old diesels because the spark of ordinary engines causes interference that can be picked up by the telescope. Hard to find aliens when some idiot is mowing their lawn with a gas mower and sparking up an EMI storm…
If we really want to get into the EMP discussion, focus on surge protection and faraday cages, not eliminating electronics.
I highly recommend anyone interested in EMP-hardening to read this government paper (PDF warning):
https://www.cisa.gov/sites/default/...CISA_EMP-Protection-Resilience-Guidelines.pdf
For those who don’t have time to skim, the most important thing that can be done at the consumer level is use of surge protection. Surge protectors operate (super crude explanation) by measuring significant over-voltages and shorting them directly to ground. They’re actually required by the latest NFPA 70 (National Electric Code) revision to be included in all new main panels. The NEC requires them for lightning strikes or accidental over-voltage (Usually high voltage lines being blown into low-voltage ones), but the paper notes that they are actually useful for EMP resistance as well.
At the automotive level, it isn’t as critical since the circuit distances are so short. But surge protection, and shielding, to a lesser degree, would presumably make a car EMP-proof enough that the car would be wiped away in any physical explosion before it got close enough to succumb to an EMP strike.
I highly recommend anyone interested in EMP-hardening to read this government paper (PDF warning):
https://www.cisa.gov/sites/default/...CISA_EMP-Protection-Resilience-Guidelines.pdf
For those who don’t have time to skim, the most important thing that can be done at the consumer level is use of surge protection. Surge protectors operate (super crude explanation) by measuring significant over-voltages and shorting them directly to ground. They’re actually required by the latest NFPA 70 (National Electric Code) revision to be included in all new main panels. The NEC requires them for lightning strikes or accidental over-voltage (Usually high voltage lines being blown into low-voltage ones), but the paper notes that they are actually useful for EMP resistance as well.
At the automotive level, it isn’t as critical since the circuit distances are so short. But surge protection, and shielding, to a lesser degree, would presumably make a car EMP-proof enough that the car would be wiped away in any physical explosion before it got close enough to succumb to an EMP strike.
Now you're cooking without gas.
I wounder how the OP feel about a Detroit 3-53. Will it even fit? Does he even need a hood without electronics under there. 
A while back, wise moderator from a another place once said the 4bt is both the most talked about and the least done TJ modification. A carbureted TJ may be a close second.