bushytails

They're going 65mph in the photo... at that speed, it should be firmly at the bottom line, where the thermostat opens. EA81s aren't picky about thermostats, since they're on top like most older vehicles - it's the newer EJ motors that have them on the bottom that are super picky. My first guess would be a clogged radiator. Where on your temperature gauge does the thermostat open? From a cold engine, keep feeling the outlet side. It'll be cold and then suddenly hot when the thermostat opens. Then keep watching the gauge, and also note where the electric fan kicks on. These are your reference points for where the gauge should read. On level highway it should be at the point the thermostat just opens, and it should never exceed the point where the fans kick on, at any speed.

That temperature gauge is *way* too high. Address that promptly or you'll be getting to do head gaskets very soon. At highway speeds the needle should be at the lower black line, and it should never get to the second black line.

I need to split a transmission soon, and I'll be replacing all the seals while I'm at it... will need to figure out how to set the gears, not just mark the positions. yay.

As subaru1988 says, they need adjusting... but they're often corroded to where the ball that senses you're on a hill can't roll freely, and thus don't work. I haven't tried rebuilding one.

Instead of dual SPFI, let's go for *quad* SPFI! ... oh, wait, that's just a MPFI manifold swap.

Same question, different sensor. Does the bucking go away if you unplug the knock sensor?

Current trend is "almost nothing is available, and what is available is usually garbage", alas...

I've been searching pretty hard over the last few years for a good radiator, and the only option in the US seems to be roughly four varieties of chinese all-aluminum models. There's a company in .au that supposedly still makes a copper-brass one, but they explicitly state they will not ship overseas, and did not respond to an email asking if they'd consider changing that policy. You can get the aluminum ones on ebay, or at o'reilly if you want a warranty. Quality... varies. The o'reilly one isn't terrible. The $90 ebay special is pretty ugly. I haven't tried the "Fenix" one for a higher price. There's a couple middle-priced ebay options. When searching, look for "leone" and "brumby" radiators, since that's what the rest of the word labels them as. If you do find a copper-brass one that's actually available in the US, let me know!

"most available".... I haven't seen one of those available in many years.

Does the bucking go away if you leave the valve unplugged?

I should add, it's just my *theory* that not having a reservoir makes them crack. I've had a lot of problems with them cracking, and here's what I decided: With no reservoir, the radiator always runs with a bubble on top. Even if you fill it to the brim, when it warms up and expands, it'll push coolant out the cap, and pull air in when it cools. At idle, the bubble is at the top of the radiator. Coolant entering the upper hose at low velocity drops by gravity and slowly flows through the tubes, with the top couple tubes filled with air from the bubble. At throttle, the high-velocity coolant against the resistance of the tubes causes coolant to flow through all the tubes, including the top ones, and the bubble is pushed to the outlet side of the radiator. You can see this if you look down the cap with it running - the level drops when you give it any throttle. So, at throttle, the top tubes are filled with hot coolant, and are hot. As soon as you go to idle, and the bubble moves into them, the airflow over the radiator instantly cools the tubes down to air temperature. Then you give it throttle, and they get filled back with hot coolant, and instantly heat to coolant temperature. Then you go back to idle, and they drain and instantly cool to air temperature. And paper thin aluminum can only take so many 100 degree temperature cycles every few seconds before cracking... especially since when they cool, they contract against the force of the rest of the hot tubes expanding the tanks apart... I couldn't find any other claims about this when I extensively searched for info on them cracking - just lots of other people having mysterious cracks in fairly new expensive radiators. So, with no other competing theories, I'll go with the one I came up with!

I got a universal stainless steel one on ebay. Google, ebay, or amazon for universal coolant reservoir, universal coolant tank, and searches like that. There's tons of nice-looking ones available.

Got a source on those? All I can find is references to swayaway, which seems to be out of business...

Hrmm, I could have sworn the 2wd still had it, but it's been so long since I've seen one, I seem to be mis-remembering!

You're doing it wrong... you take off the shocks, then the three bolts on the trailing links, then the inner bushes, then drop the gas tank, then bolt up the 4x4 gas tank, the mustache bar and diff, and the trailing links with CVs...