Dee2

It does sound like it's some kind of electrical thing. I suspect a fuel problem would occur at a wider range of RPM. Weird intermittent things remind me more of a loose connection somewhere. Or as you say, something is beginning to fail. With the "stumble" or "missing" I would also check for loose connections like spark plug wires. Check the distributor and clean the contacts as well. Tracking it down may require waiting until it becomes more consistent.

Just as a sidebar, so folks can be aware, a vacuum gauge will also indicate if there is a restricted exhaust. A little easier than having to drop the Y-pipe

Throwing parts at the car is not the right approach. find out what the problem is first. You can clean and sharpen spark plugs. You can clean contacts in the distributor. Cleaning the throttle body and MAF is a good idea, but only if they need it. Inspect first. That could just mean you have an intermittent problem.

If your engine is not running properly and you want to fix it then you first must get some diagnostic information and make some physical checks. After checking for codes, one of the best things you can do, which is fast and easy, is run a vacuum test on the engine. Here's a couple of links telling what can be learned and how to interpret the gauge. This will help to eliminate whether your engine has any major problems. Likely it does not, but it only takes a few minutes to check. https://dannysengineportal.com/vacuum-gauge-test-tells-you-a-lot-about-the-condition-of-your-engine/ http://www.secondchancegarage.com/public/186.cfm Also, when was the last time it had a tune up ? As already mentioned, check the plugs, check the distributor cap, check the timing, check the air filter and fuel filter. Check the oil and transmission fluid levels. More comprehensive would be to check the engine compression and do a fuel system pressure check.

Replacing all those items means you won't need to do all the physical checks. Focus on getting the diagnostics and repair things that were broken.

Something is clearly wrong there. Perhaps the grounding, the coil or the coil cable. But at least you know where to focus your efforts. You can take the coil in to a shop and have it and the wire tested. If they check out then you have a grounding problem. You can also verify if it is the right coil for the vehicle. Maybe they gave you the wrong one (?)

If your engine is not running properly and you want to fix it then you first must get some diagnostic information and make some physical checks. One of the best things you can do, which is fast and easy, is run a vacuum test on the engine. http://www.secondchancegarage.com/public/186.cfm Also, when was the last time it had a tune up ? Check the plugs, check the distributor cap, check the timing, check the air filter and fuel filter. More comprehensive would be to check the engine compression and do a fuel system pressure check.

I would skip the extra ground wire and simply hold the coil wire (use insulated pliers) next to a ground surface while someone cranks the engine. See procedure from link provided above. If you get a good spark then the coil and coil wire are good. If not then one of the two is bad. That would lead to the next step, the distributor. Are you changing the cap with each new distributor install or are you using the same cap ?

Seems unlikely that all the distributors would be bad. So I'm going to assume that's not the problem. You have a new coil, plugs and wires.... what about the wire between the coil and the distributor ? A weak spark from the plugs or a weak spark from the coil ? There's some specific tests outlined here chapter 9 troubleshooting for coil/plugs/ distributor. See if there's anything there that you may not yet have tried. http://www.suberdave.com/USMB/HTKYSA.PDF

Some caliper pistons need to be "screwed in". Simply compressing them can cause damage. Check your repair manual to make sure which is yours. If you don't have a manual, check here: http://www.suberdave.com/USMB/HTKYSA.PDF

If you don't have a service manual, then to find out how to adjust your carb, look here: http://www.suberdave.com/USMB/HTKYSA.PDF Chapter 7 procedure 12

Step #1 :: Read the codes

Is this a sudden new problem, or has it been getting progressively worse ? Have you checked the fuel filter(s) ? Checked for fuel line restrictions ?

What all was done? If it was okay before the work then something about the reassembly or the parts is at fault. Look at the other side and make sure everything is assembled exactly the same. Verify / compare parts to ensure everything is same-same and nothing was omitted.

This site provides a lot of VIN info at no cost. I just used it to research a vehicle up for sale and I was impressed by the amount of info provided. Very similar to carfax and a bit more in the way of specifications. https://vincheck.info

You may have just lost a balance weight. I'd go back and have them double check.

Rockauto has some replacements units https://www.rockauto.com/en/catalog/subaru,1987,brat,1.8l+h4,1267769,brake/wheel+hub,master+cylinder,1836

It's unlikely the master cylinder was affected by the repair work. Getting air out of the system can be a bi*ch. Don't ask me how I know. Bleeding system is best done with two people.

If you want to easily improve your gas mileage, replace your oxygen sensor. Then clean, sharpen and regap your spark plugs.

I'd be curious to see photos of the car.

If it's not leaking then yes, that's a good thing. [update below] Did you change the oil filter when you resealed the pump ? If so, then the old oil filter may have been extra dirty and giving you a higher pressure reading. The new filter is clean and could be resulting in a lower pressure reading.

Some photos here: http://www.dirally.com/forums/showthread.php?2726-ea82-Oil-Pump-R-amp-R

Probably a bad MAF. They can go bad.

This may help

When I took mine off I couldn't tell any difference. The engine noise was the same to me. I don't think the covers affect noise of the engine.