pruney81

you might want to get a new gasket for the the 2-stage, also the temp gauge in that truck might be messed up or the sending unit. Even after I put in the dual stage it would still shoot up and then come down, just not as bad as it was before. Even my 1990 now with a dual stage goes up to half on a cold start then settles back down to 1/4.

txclimber

yeah. I got the gasket too. I found it online for $30.13, here:

https://www.toyotapartscenter.net/toyotaoemparts.html

If anyone else needs it the part # is: 9091603070

Toyota will try to sell you 9091603078. Make sure to check the last digit.

pruney81

I wonder what the difference is between the 078 and 070. nevermind, the 078 is the regular one.

1990yota-pickup

well buy bought and post the difference

txclimber

Ok. I got the fancy 2 stage thermostat. Slapped it in and...same thing. Still had the temperature overshoot problem. It would get about 3/4 of the way up before it would come back down. Not only that, it would creep back up and down the whole time I drove it.

I looked at the cheapy one I had and noticed it was for 82 degrees, not 88. Another trip to Autozone, $5 for another thermostat (88 degrees). I snipped out the jiggle valve and put it in.

Perfect. No temperature overshoot and it sits right where it's supposed to. I think perhaps the toyota 2 stage I got was defective. The $5 fix works for me

1990yota-pickup

good deal

pruney81

weird. I'll bet she runs better now than ever. Alot of memories in that truck. It's good to see it's served you well for this long.

cgeorge

what is the deal with the thermostats? My truck has done the same - goes up to about 1/2 way then settles back down below the halfway mark. I remember when I had my 89 (bought it new back then) it would NEVER do this. My truck has a aftermarket NAPA thermostat (new) and it does the same thing as the Toyota OEM.

Sounds like, from txclimber, we should all remove the jiggle valve?

cgeorge

what is the deal with the thermostats? My truck has done the same - goes up to about 1/2 way then settles back down below the halfway mark. I remember when I had my 89 (bought it new back then) it would NEVER do this. My truck has a aftermarket NAPA thermostat (new) and it does the same thing as the Toyota OEM.

Sounds like, from txclimber, we should all remove the jiggle valve?

cgeorge

sorry about the double - post. Not sure what happened there.

1990yota-pickup

i never even seen my temp gauge evn get up to the halfway mark..

Teuf

My Fancy Dan, Band box spiffy 2 stage works good, shoots up a bit then down to the 1/3 spot. The one I replaced would go up to 1/5 and sit there, was cool if you ask me, ran richer i think.

dwnhiller93

Something is wrong with your temperature sending unit then

Philbert

iTrader: (2)

My local junkyard (the Toy Connection) gave me this same tip when mine did the same thing - the spade does the trick, with some heat shrink tubing

txclimber

Uh Oh! Man I need some help here. Feeling pretty disgusted. Took a road trip and on the way home huge power loss. Running great one minute then had to keep my foot on the floor just to keep 60 miles per hour. Before cruised at 75 with half a pedal to go.

Limped home and started tinkering.

Catalytic converter rattled. Replaced everything from cat back. Muffler was partially plugged.

Helped, but still not where I was right after rebuild.

Replaced O2 sensor...No change.

Replaced plugs, even though it's only been about 600 miles since the were put in the new head. No change.

Worried that my head gasket already went.

Did compression check:

1 166
2 165
3 175
4 180

What can you tell from these numbers?

I'm really beating my head against the wall. It ran soooooo great after the new head and cam. Not anymore.

By the way, I've rechecked the timing 5 BTDC with the thing jumpered.

Also checked valve lash.

No coolant loss found.

Please help.

Power loss seems to be most noticable at highway speeds.

Philbert

iTrader: (2)

This is a shot in the dark, but maybe it's coil/alternator related?

when my alternator died on my Datsun on the freeway, it was a power loss that came out of nowhere - foot to the ground and it just decelerated all the way to zero. Maybe yours is starting to go and you're getting enough juice to run, but not little enough to die.

Again, total shot in the dark - if nothing else, hope my reply will bump this thread enough to get the attention of someone who knows more than me!

Good luck - keep us posted!

Mountain Cop

Compression+spark+fuel, right?

You have compression.

Check for fuel flow.

Check for a good spark at the plugs.

That's the simple stuff. Good luck! MC

1990yota-pickup

it reads just below the half way mark... just like my old 82 would... never had a problem with either truck... its still working fine and i wont fixit until its broke..

txclimber

Everything still checks out ok.

Philbert: Good suggestion. Seems weird to me that alternator would have anything to do with it, but some google searching agrees with you.

I did have the Brake and Charge lights flash once, very briefly which also points to the alternator.

Checked the belt and it seemed a tad too loose. Tightened it up and then put a meter on the battery terminals.

12.2 volts with truck off.

14.4 volts with truck on and wipers, flashers, radio, and heater on high.

That seems to tell me that my alternator is working ok. Maybe I should have checked it BEFORE I tightened the belt.

Test ride shows that I still have a loss of power, but it seems better. Not sure if tightening the alternator or the new tank of gas I'm now on is helping.

Bad gas? Loose alt belt? What else should I try?

txclimber

I'd like to run a bottle of fuel injector cleaner through there, but I'm a little afraid.

Seems like when I tried that a year or so ago all of my head gasket problems started. I guess the buildup was the only thing holding it together.

Are these safe? Could it hurt any of the gaskets?