DaveT

The stock gauges are only roughly accurate while driving, if they are working. Idle, they will look like zero. For real checking, get a mechanical gauge. If it's reading very low while driving on the highway, it could be the sender or the gauge. Or some kind of real problem....

Idle oil pressure will be very low. No load on the bearings anyway, so no problem. Stay with 10w 40. Don't lug it, these engines are made to do higher rpms. The factory guage is not accurately calibrated, especially for the pressures at idle.

Yes, I will update. Things have been a little nutty here.

If the intake gaskets are original, they are probably leaking by now. If you replaced them with anything other than oem from a dealer, they will fail in a fairly short time. Ypical way I decide to dissasemble to check those is after verifying that I cannot find any other seeping leak, and that I am not getting exhaust gases pressurrising the cooling system. The best way I have found for removing the 6 manifold bolts without snapping one is to drive until the engine is at normal operating temperature, then park it in the garage and immidiaty and carefully remove the 6 bolts, while everything is hot.

Lucky so far.... once there is enough air in the system, it will go over normal temperature. Then it's too late. Also, if the radiator is older than 5 years, carefully inspect that the fine fins are attached to the flat tubes. Especially if you are in snow country.

I have done some that way previously, but now that they are near impossible to get oem , I had to find out how to deal with the dirtier ones I had set aside.

Forget the extractor. Those only work for new clean bolts that snapped off. Never for old rusted ones. Penatrating oil, them try a pipe wrench, unless you are lucky enough to have an open end wrench that big.

Ig it has an EA82 engine, there are 7 cooling system hoses. Check all of them. Check the radiator. Check the water pump. There should be very little to no air in the radiator. The best way to check the coolant level in the radiator is sharply squeeze the upper radiator hose and listen for gurgles and the jiggle pin. Cold engine, off. Opening the radiator cap allows air into the system, and you cannot monitor the quantity of air if you break the seal while trying to check. Beginning of headgasket failure is most often coolant missing slowly. , as it progresses, bubbles in the recovery tank. . Once you get over normal temperature while low on coolant, the failure rapidly gets worse . Until you find and stop the leak, check the level and air before each start from cold. If you use the temperature gauge as a coolant level checker, you will be needing headgaskets.

To get the outer joint off the axel. Get a 12 inch piece of 2x6. Drill a hole just big enough to fit the steel axle through, after removing the inner joint. Clamp the axle in a vise with the joint end down. Put something under to catch the joint. A moderate hit on the block of wood should pop it off. Now you can clean, and inspect, and regrease much more effectively.

Did it used to work? I had a 76 and a 78 that had the voltage regulator separate from the alternator. I'm not sure how 79s were made.

If I am following everything, it sounds like that running a wire from the output side of the fusible link for the white wire to the junction near the fuse box makes it run? As long as you are NOT bypassing the fusible link, you should be ok. I would rather find the bad connection or break. If it were at the branch for the alternator, you may one day burn out the alternator [or maybe just run the battery dead] if the rest of the connection fails.. Replacing the whole harness is a big project, and you have to find one...

I have seen a wire break inside the insulation. It was very tricky to spot the break, just a little anomaly in the smoothness of the insulation. Almost has to be that kind of thing, or the crimp where the alternator ties in is bad. Bad crimp more likely, so look for that first.

Iirc, it has a junction to the alternator. Like the one in your picture for the fuse box. I want to check that next.

If you ran a wire from the white wire on the link box to the joint, and It made no difference, and when you ran a wire from the joint to the battery, and it worked, that narrows the problem down to the fusible link, one of the connections, or the wire that goes from the link box to the battery, or its connections.

Getting voltage dropping on a wire that size implies a lot of current, which makes no sense, as the battery isn't dead - it would be long a go. But if the battery reads 12V at the terminals, and the voltage at that joint is not the same, there is a high resistance somewhere between that joint and the battery. Keeping the meter negative lead on one ground location for all test - don't move it. Do a recheck of the (+) battery voltage, right on the lead post.. Can you get the meter connected to the white wire on the back of the fusible link box? what is the voltage there? As a test, any 12V light you have laying around connect to the white wire joint, and the other side of the bulb to ground - what does the voltage do? Dose it light?

The joint in the picture looks good, nice and clean. If things work with your "jumper wire" feeding that point, the problem is somewhere between that connection and the battery. As things are now - without the added wire - does 12V show up at that joint? Does it stay there if a load is applied?

Your 10:27 post tells a lot. Look for a bad connection between the back of the fuse box and the battery. Put the voltmeter on say the white wire on the fusible link box. Turn on the parking light switch, as a test load. Like I wrote above.

Fuses fed by the heavy white wire - Heater | Heater | Stop & Room & ECC | Position (= parking light switch ) Middle row is here, none on the white wire. R-DEF | R-DEF Those not listed are not on the white wire. Try the rocker switch on the top of the steering column. That is the parking light switch. They should light even without the key in the ignition. If they don't, continue tracing the white wire problem. It is also good to put a load on circuits as part of testing - that is, say you have your voltmeter on the white wire, and it shows 12V. put that switch on - does it stay? Change a very small amount down? Or drop to near zero? [assuming the lights do light]

Does the always on power at the fuse box stay there while you are turning the key? Yes, then trace towards the ignition switch. No, look for a flakey connection back toward the battery.

Before you remove the fender - check [or double check] - The fusible link box is mounted to the overflow tank. It comes off by pulling and wiggling. Get it oriented so you can inspect the wires where they come out. You don't want to see corrosion or burned / discolored insulation. There are 4 wire on one side, and one wire on the other side. The single wire is the connection to the battery. While it is loose, get a meter probe on the contact for the heaviest white wire. This is the feed for the always on fuses, and the alternator output terminal. That should have 12V on it always. If it doesn't, the problem is the link, one of the contacts, or the wire that goes to the battery. The other 3 also should have 12 V on them always. IF there is 12V on the 4 wires, and not on the fuses, I'd want to check the back of the fuse box, the big heavy white wire, before pulling the fender. Don't know if you checked or anyone mentioned, but also a good idea to verify the 2 ground wires on the battery (-) terminal - the fat one to the starter mounting bolt, and the mid size one that goes to the body..

Tests with engine running, room temperature, not run long enough to get to 190. Pinched off return line gets me 45 PSI. Current drawn by the pump rises noticeably while doing this, which does not surprise me. Put a vacuum gauge on the small line to the pressure regulator, get no reading = no vacuum. Manifold vacuum looked normal. Fuel pressure still doing the bouncing between 20-22 PSI Still have to check the other things.

Some new data: On my 93 the fuel pump is getting 12.5V while drawing 1.37Amps. Does not change much at idle VS heavy throttle. Drops to 1.35A On the 1987 - Pump is getting 13V while drawing 1.26Amps. Didn't get to try heavy throttle w/ high RPM, as my yard is too small, and I didn't care to risk getting stuck anywhere at the moment. The fuel pressure is odd. however - instead of a steady 21PSI, I have the gauge bouncing between 20-22 PSI - steadily, at a pretty good rate that a mechanical gauge can keep up with. Does not vary with throttle position.

Waxoyl helps.

It's been a crazy few days... I will let everyone know what I find. Thank you for all of the suggestions.

4000RPM at 65 is very normal for the 3AT. From around 88 and up. My 86 had slightly different gears, and was a little lower RPM at 65. But even more gutless.