I recently "inherited" my son's '87 Supra. No, he is not dead, he just got tired of old cars and bought a sexy new RSX type S. I need to get this car running very soon so I need help diagnosing it's issues.

It is a manual, non-turbo. Head gasket replaced several years ago. Small hole in top of exhaust downpipe.

Main problem: Apparent miss-fire. Car bucks when first started and sometimes when decelerating with foot off gas. Also idling at about 1800 rpms. I noticed that while the engine is acting up I can hear the servos on the struts turning back and forth. This started last Wednesday.

Secondary problem: Car is overheating. Son says it did not do it before. He let the car sit for several months (maybe 5) before I started driving it. It overheats after a pretty consistent interval of driving. It did it for a short time but had stopped for nearly a month before it started again. I can hold it off if I set the heater to 85 degrees and turn the fan on high.

I await any help I can get - thanks in advance!

well.... i guess that you could try checking the plugs and leads... make sure they're still in good condition

you aren't by any chance pushing the normal and sport button at idle? lol... i haven't really heard of the tems actuators constantly going at idle... maybe a tps problem?

maybe the radiator is blocked? low on water? small water leak?

when is it exactly overheating?

when the TEMS are set to "sport" they are very sensitive and i guess the engine jumping around could make the the system twitch . i wouldn't worry about them right now .
set to "normal" ?
when i see over heating on a mkiii i always assume the worst. but i'll pass on those comments for now .

you need to check that whole cooling system out and start taking note on how much coolant fluid is being used . in the main radiator and the bottle up front . speaking of the bottle up front is coolant being pushed out from that ? is it sealed ?
have you seen water yet or just temp gauge indicating over heating ?

When the car is overheating (it did not do it for about a month) it can be driven at normal speeds for about 20 minutes. The temp guage stays in its 'normal' position up to that time then begins to climb. on a couple of occasions I could not get stopped soon enough and water began to boil out of the overflow bottle.

When this first happened I babyed the car with the heater on all the time. After about a month of this I scaled back the heater and babying until everything seemed normal. Then my younger son used it one night and it overheated again. I did notice when I tried flushing the cooling system, as the water drained from the radiatpor I heard a lot more sucking noises than I would normally expect and thought maybe the radiator may have become junked up from sitting for so long (original radiator and over 110k on it). I guess I need to ascertain the status of the head gasket just to be sure. The former owner has a very heavy foot...

The TEMS button is in "normal" when this switching occurs. What is it specifically that triggers the tems to switch to a stiffer setting - is a single sensor of a combination? Is the bucking and switchin from the same fault or is the switching a result of another, separate problem? Could the cruise control have an affect on this? My son said it did not work but I could have pushed the buttons by mistake. I will check the plugs and wires but I wanted to know what else to look at since I will need to take apart so many things. Could loose vacum lines cause this (he asks knowing that vacum lines often cause many glitches...).

Sorry for the length of this post...I have two geriatric Toyotas in the driveway and It's all very frustrating just now.