What he said, only with paragraphs...
.
The VERY first thing I do is break out a COMPLETE manual (or two).
Nothing else you will do is as important as having an ACCURATE & COMPLETE MANUAL.
.
The next thing is compression testing,
And *IF* it runs, a vacuum gauge test.
There is a VERY specific reason, engine health is everything, without a reliable power plant it's just spare parts until that is fixed.
A compression gauge will tell you if the cylinders, rings, valve seats, etc are up to snuff.
Now, it doesn't have to be perfect by any means, there is still a lot of life in older engines, particularly if you know what to do about the wear and issues.
Don't know about the issues, you can't do anything about it...
The vacuum test will tell you how that 'Air Pump' you call the engine is functioning.
Most things that show up in a vacuum test can be fixed without tearing into the bottom end of the engine.
Vacuum test will tell you about sticking valves, bad valve seals, leaking gaskets, carb & ignition problems, etc.
Often much more accurate than a 'Computer', not that we have computers anyway...
.
The next thing is like above, SINCE YOU HAVE POWER, YOU MUST HAVE BRAKES!
Wheels come off, seals, bearings, brakes, etc are checked & corrected as needed.
This is where you flush the brake system, look for rusted brake lines, etc.
Brakes are mandatory, it's your LAST line of defense...
This is a real good time to get differential cover gaskets (confirms the axles are what you think they are) and clean out the PO (Previous Owners) crud & mistakes.
Now you know the thing is going to STOP, and the wheels aren't going to fall off going down the highway...
.
Oil leaks are something that can be fixed later,
But fuel leaks are something that needs to be fixed NOW.
Jeep carbs are dirt simple, and a good manual will show you exactly what you need to know for a basic cleaning & adjustment,
$10 worth of replacement rubber lines & clamps won't bust the budget, but might very well keep your 'New' Jeep from burning down.
.
Now what I tell people is,
If you CAN'T repack/replace wheel bearings, clean out a carb, flush/fix brake lines, then you have no business trying to mess with an old vehicle of any kind.
An out of control vehicle is a deadly weapon, get the dangerous fixed first, ignore the rest...
(It's a matter of common sense that the world seems to be lacking today)
.
You *Should* have looked over the frame for rust through/breaks, broken springs/shackles, broken steering, etc before you bought, and now you go after the rest of the dangerous issues.
Not everyone will have the education to do electrical, its a different discipline than turning nuts & bolts, and it takes a specific education...
The 'Trick' is to find someone that actually knows how the system is *Supposed* to work, and not someone that tells you to rip out the wiring,starting from scratch with some kit or another...
With some basic education, any circuit can quite easily be re-built without throwing the baby out with the bathwater,
A good manual will have the wiring diagram, several of us have even color coded & simplified the diagram for laymen, and listed how to trouble shoot nearly everything on the Jeep.
Once you understand what's wrong, how it's supposed to work, a few wires and connections and it's usually working as good as new, maybe better than new since AMC had the worst wiring harness of any US manufacturer.
"One Size Fits Nothing" harnesses can be scabbed in, but not being specific to the vehicle you have to make 'Modifications' to make it work, and that OFTEN takes more time than remaking the entire harness with updates to specifically fit the vehicle.
.
Then it's off to the transmission/transfer case...
Again, if you are mechanical, with a good manual, it's not too difficult to refresh either trans/transfer...
Often just bearings, seals, some new wear parts and you are working well.
Most people that will dive right into an engine won't touch a gear box, the gearboxes being MUCH more simple than an engine...
I usually recommend skipping the local transmission shop opting for an industral rebuilder to do the job.
It's usually faster, cheaper, and you get a warranty you can count on.
The draw back is pulling & installing the gear box, the industral rebuilders don't usually do that while the local shop will, but charge you out the butt for the service.
A remanufactured gearbox is perfectly acceptable, trade yours and some cash for one just like it with a warranty.
Again, the larger industral rebuilders will usually have the best deals.
I don't think any less of someone that seeks professional rebuilds rather than take on the task, buy speciality tools, get an education, buy the manuals, etc.
It's a time/cost issue and I understand that all too well.
My hat is off to the guy that takes it on for ONE or two gearboxes, but it's not cost/time effective.
.
The ignition system, the fuel supply system WORK TOGETHER...
Unless you FULLY understand how they interact with each other then you often misdiagnose running issues.
This is the most complex interaction you will have to deal with, and it's taken in bits & pieces WAY too often.
The fuel, spark timing, valve timing interaction is VERY complicated, and it's also the most misunderstood thing I see since everyone *Thinks* they have exactly the *Correct* information to start twisting on the distributor, turning screws on the carb, but don't have the most basic tools to test/find the actual issues.
While everyone says a 'Timing Light', a pencil & paper is mandatory.
If you can't ACCURATELY graph these...
1. Base ignition timing, from the crank, as in verify the valve timing is correct, the balancer isn't lying to you, the rotor phasing is correct, etc, you don't have a base line to start from.
EVERY 'TUNE UP' *Should* start with finding TDC of Compression Stroke (not exhaust stroke), and confirm you have compression so valve timing is working...
2. Manifold vacuum,
3. Exhaust temp,
4. Accelerator pump fuel supply,
5. Accurate engine RPM
And all that graphed in a useable form...
This will get you the BASIC ignition & fuel working together.
To get an operational graph, you will need to spec the distributor advance, learn to read plugs, and attach vacuum gauge to the engine so you can see what the ENGINE is doing under all conditions.
The 'Easy Button' is simply to restore the fuel/ignition to factory specifications,
Which again means you need a baseline 'Zero' to start from,
A distributor advance curve, so vacuum pump, vacuum gauge, accurate timing light, etc...
AND that pencil & paper...
'Trust' nothing, VERIFY EVERYTHING, prove anyone else's claims that's supplied parts or worked on the vehicle...
Something as simple as the rubber in the balancer giving up or a rotor with misaligned conductor tab can screw things WAY up...
VERIFY EVERYTHING!
