[MK2Racer]

Okay, here is my problem: When I start the car, it runs rough. When I drive, at first everything is okay. After about 3-5 miles of normal driving, I lose power and my temp needle soars. After about 1 minute of this the radiator boils over. I try to avoid that whenever possible so I havent driven it in a few days. Anyway, a few weeks ago I overheated it bad (before I had any problem, this was my own fault). Since then I replaced the valve cover gaskets (unrelated problem) and the thermostat and thermostat gasket (which I toasted in the overheat). I dont blow any smoke and im not leaking oil or antifreeze inside or outside of the engine. I thought of the timing, but cant seem to locate any timing marks on the belt. In the process of fixing my thermostat, I had to remove the distributor (dont ask another long story) Is it possible I put it in incorrectly? To my knowledge, if it is in the wrong position then it wont run at all or extremely poorly. The only other thing I can think of is this damn sensor I broke off replacing some vacuum hoses that were old. I believe it to be a baro sensor, maybe, but im not sure. Two vacuum hoses run from the top of my EFI to it, one has a vacuum source, the other nothing, and the sensor itself has an electrical plug on it. I posted a while ago about it, and someone said to plug the source and that it didnt matter. Is this true or is that my problem? Also, does anyone know for sure what the sensor is and/or where I can get one? I pulled one off of my 3sfe 87 camry engine, and it is similar but wont work, and I got one from an 85 5mge automatic and it is even more different than the camry one. Any other thoughts? Any help would be very much appreciated!
-Ken

 

[MK2Racer]

Here is what it looks like


http://www.geocities.com/mk2racer/IMG00011.JPG

 

[Square]

Hi,

I couldn't see your picture. The link took me to a page that said the pic was unavailable.

As for your problems, first the distributor/timing issue. Yes you can put the distributor in wrong. Even if you insert it right, you will still need to have it in the right spot in the adjustment slide before you tighten the bolt in order for the motor to run properly. If your car starts and runs (albeit rough) then you must be somewhat close to the correct timing. You will need a timing light to set it properly. You mentioned not being able to find the timing marks on the belt. What marks and what belt are you referring to? The mark I used was on the crankshaft pully and the degree indicators were on the timing belt cover on the driver's side top of the crank shaft pully.

As for your overheating problem, if you have changed the thermostat recently, did you get the air out of the system after you installed the new thermostat? If you just installed a new thermostat and sealed everything back up, then I think you would have air in your system which would cause the overheating you are describing.

Please let me know what your situation is regarding these questions and I will see what idea's I can come up with.

Also, if you want to look at my 83's vacuum line routing, you can find a pretty decent set of pictures here:

http://sailfish.exis.net/~sfsound/supra_page/fuel_leak/fuel_leak.html

 

[Flyin' Hawaiian]

Try this for the pic:
http://www.geocities.com/mk2racer

 

[Square]

Thanks Hawaiian,

I can see the pic now.

 

[MK2Racer]

The belt I refer to is any of the drive belts on the front of the engine, it is usually on one. Maybe on this car they arent there, but on all my other cars they have been (non-supra's). As for the air thing, I ran the engine and filled it with fluid, so there "should" be no air to my knowledge. Unless there is another method of removing air that I dont know of. Also, the bottom picture is the sensor I broke. There were two plastic vacuum connectors, one is facing down, the other faced right - that is the one I cracked off. I tried to glue it and it did not hold. In addition to what I said earlier, I blocked off the vacuum cource FROM the EFI so there was no leak, then I manually applied valuum TO the EFI (the other of the two hoses) The more vacuum I applied, the higher my idle got, to a point. So it seems that it IS an important and I cant just block it off.

 

[zank]

as far as i know to remove air thats in the head you would have to jack the car up (front of car) open your radiator cap and turn your heater all the way up. Then run your engine till its at normal operating temperature.

Thats what i have heard. hope fully some one can back me up on this one

 

[RWDCelicadude]

I don't know about the jacking up but you should definitely start the car and let it run till it reaches operating temperature with the radiator cap off and the heater on. You should see bubbles coming out and possibly water/coolant, as well, as the bubbles work their way to the top. Keep watching it and if you see the water level drop add more fluid, you can also watch to make sure the fluid is actually circulating through. If you don't see any movement after ten or fifteen minutes of idling you may have a bad water pump, which will definitely cause the overheating you're talking about. Good luck with it.

 

[Square]

Mk2Racer,

Thanks for the update. OK, The photo of the sensor that broke. Was the sensor located on the bottom of the air chamber where it bolts to the intake runners with 2 vacuum lines plugging into it from the metal multi-tube vacuum routing assembly? If so, it is the Vacuum Switching Valve for Exhaust Gas Recirculation (according to page EC-3 of my Shop Manual). I do not know exactly what that is, or does, though. But you should be able to ask a dealer if you can still buy one new from them. If that is not it, then tell me where it was, and I will look it up in my manual as best I can for you.

As far as your over heating problem, I have heard more than one person say that it is best to elevate the front of the car, and almost all discussions included the advice to run the heater while "burping" the system. So, that may be a possible fix for you.

As for the timing marks, the only ones I know of are a notch in the crankshaft pully and the degree indicators on the lower timing belt cover on the drivers side just above the crankshaft pully.

 

[MK2Racer]

http://www.geocities.com/mk2racer/Sensor1.jpg</img>

A pic of the sensor where it was located. Two lines did come from it, and go into that thing with the large white plastic screw on top of the EFI. By adjusting this screw, I can make the car run leaner or richer, so I assume that the thing I broke controls my mixture to some degree. I have ti have the screw cranked all the way out to start the engine, and it runs fine until reaching operating temp, then I lose power and begin to overheat. If I get out and crank the screw all the way tight, it will not over heat quite so fast, but I still lack power, and still overheat. Also, I now notice some antifreeze leaking from underneath somewhere, havent pinpointed the exact location yet, but I pray it isnt the block. If it is the block, where might I find a 6m block for cheap? And what from the 5m could I use, or maybe I should say what can't I use from the 5m? Basically, im on a kinda tight budget, Ive got a max of about $300 to throw at this problem for now. I hope it isnt the block, but if it is, maybe now would be a good time to get a new one? Also, on top of the cost of the block, what other costs might I expect (I have never rebuilt an engine before)/ I expect a gasket set (dont know how much), but other than that... no idea.

 

[Square]

The item in your picture is the item I was referring to. That is the Vacuum Switching Valve (VSV) for your EGR system. To the best of my knowledge, an EGR system failure cannot cause your car to overheat, it can only cause you to have lots of emmissions and a rough idle and loss of power. I believe that your overheating problem is being caused by something else.

My first suggestion is to inspect the water pump weep holes to see if the bearings are gone. You cans also look for leaks around the pump and take the belt off the water pump and see if it turns freely.

My second suggestion is to drain the radiator, then refill and purge with the front elevated. I think you just need the front high enough that the radiator cap is above the engine. This is a possible cheap fix, and I would do this before spending any real money. If it dosen't help then your not out much.

My third suggestion is to remove the thermostat completely and see if your overheating situation goes away. If it does then you know your thermostat is bad. If you car runs a lot longer before overheating, then you either have a leak, a bad water pump, or a clogged up radiator.

Let me know what you find.

 

[MK2Racer]

YES!! Finally, it works again! I was going to dring the radiator and flush/fill it, when I noticed a hose full of antifreeze. Traced it back, and it hooked up to the thermo. housing. Sure enough, it was cracked and brittle by the housing! Under pressure, she leaks! Replaceed the hose and voila! No more leakage, no more overheating! I epoxied that sensor, and it seems to work, now I just have to time it and ill be doing good! Thanks everybody for the help, I really appreciate it!!

 

[Square]

Happy to hear your problem is solved! Helping each other solve problems is what this board is all about (IMHO anyway). :wink:

 

[dohc82]

Glad you solved your problem I would still recommend jacking up the front and running it to remove air.. The supra head is notorious for trapping air and its very hard to remove. I still had bubbles months after my rad hose replacment. I jacked it up and ran it till nothing bubbled. My full car took a surprising amount of fluid once the air was gone :shock:
-Wil