Several problems with 1986.5 Mk3

[essial]

I just bought this car from my step brother (because I have the money to fix it up and he wanted a car he could just drive and not worry about) so I've come up with a list of issues and fixes. This supra has been modified a bit, namely, I've been told the transmission (it's an automatic) has been replaced(?) with a sports transmission (when you put it into drive or reverse it kicks it hard into gear, and shift like that too).

My first question is about engine power. It seems that after about 3,800rpm, the car gets a nice kick in the butt and really takes off, but getting up to 3,800rpm feels like driving a minivan (it's like two totally different cars below and above that mark). A second (and possibly related) issue is that for the first minute or two after starting, the transmission refuses to shift out of first gear. After the first few minutes it shifts great. I've been told that a new throttle position sensor has been installed (before, it simply would not shift out of first at all, ever), and set dead center (which explains why it idles at around 1,200 rpm). I'm going to adjust the sensor to the proper settings this weekend (gotta start learning somewhere, and I got the manual), but was wondering if the shifting and weird power issues are related to that, or something else.

Secondly (and this may be very simple). Again, the first few minutes after turning it on, it has this horrible screechy sound like you hear with some clunkers going down the road. Pressing the gas (in park) will make the rate of screeching increase. After a few minutes, sound goes away and never returns (though early on sometimes turning makes it start back up for a few seconds). I do know the steering pump hose is leaking and thus there is no steering fluid (and thus no power steering) in the car right now, which I plan on replacing once I snag a new pump hose (the shop wanted $300 to replace the hose, no thanks). Just wanted to make sure that this is the most likely cause of the screech and not something more serious.

Anyway other than a few startup problems, the car is great fun to drive, and it feels great being one of the only stylish 80-s style cars I see out on the road. It's already been lowered and has low profile rims (yeah, teenager previously had it), so I'm mainly using it as a spare car, and as a way to learn how to work on cars. Although it's a bit annoying with the extra attention it gets.

[cre]

Sports transmission? That's new... I'd like more info. I've seen them rebuilt for more aggressive use but never heard of anyone referring to that as a 'swap' of any sort. Sounds more like bullshit to me. Typically hard shifting is due to a problem, start with checking for diagnostic codes and test the TPS (Throttle Position Sensor). See the MKIII FAQ for a thread on how to check for ECU diagnostic codes. Transmission Diagnostics are here.

I'm assuming this is a N/A... In that case the kick at around 4K is the ACIS system. Inspect the VSV, actuator and vacuum hosing which runs to the center of the intake manifold on the underside.... might as well replace all vacuum tubing while you're at it. The ACIS is a system which uses a butterfly valve inside the upper plenum to modulate airflow and help control torque below 4K. If it's not functioning the car will accelerate poorly (Cressida's didn't have this for example and have poorer throttle response). The 7M-GTE doesn't use this system as it is boosting well before and thus this would largely be wasted on it. I can't find my info on diagnosing the system. I believe that when the engine in in operation racing the engine to around 4K will cause the actuator to activate and you can see that from above, leaning over the driver's side fender and looking down between the plenum and engine (make sure the engine has been run for a couple minutes prior to this, it's not good to race a cold engine).

I'd replace the belt first... It can cause nasty noise and a lot of shops are all too happy to agree with you that something must be horribly wrong. Here's a link to the TSRM's section for power steering:
http://www.cygnusx1.net/Supra/Librar....aspx?S=SR&P=1

That's for a '91 though and there are some subtle differences.... for the most part it'll get you through a replacement of any component. I HIGHLY recommend you buy a copy of Toyota's Service and Repair Manual for your year Supra... it's an excellent resource and MUCH better than others such as Haynes which try to group many years and models into one book 1/3 the size.

[trd_brad]

did you check the transmission fluid level?(not trying to be a smart a$$, its usually the last place people look for tranny issues)

[essial]

Transmission fluid looks good

Here's some shots to show what I'm working with (note: That run down trailer is on my neighbor's property, he used it to store boxes until a tree finally fell right into it!):




I did notice something a bit odd under the hood. A device that seems to have some sort of cotton plug, but also seems to be designed to fit a hose of some sort:

Edit: Apparently this is the "VTV" which is an emissions thing dealing with opening the throttle valve slightly more at idle causing air-fuel mixture to burn completely (I'm assuming this has to do with the fact that toyota supras are supposed to run a tad 'rich')

And lastly, I'm assuming this is the acuator:

What is it supposed to do when it 'activates'?

Sorry for the newbie questions, I'm just now getting into cars (I'm a software engineer by trade). And apparently I have the Supra/Celica Haynes manual, I'll look for the proper supra repair manual online (ebay or whatever) in a few weeks.

Thanks so much for the info thus far!

[trd_brad]

bad tranny then? maybe when cre is on he can elaborate more for you.

but definatly take a good look at your fan belts as far as the squeeling goes. they do that when thier loose/ garbage

[cre]

The second to last item (the thing with the cotton) is the restrictor for the "dashpot"; Air enters freely from the open end and exits slowly from the side with the hose. The rubber thing on the end with the nylon filter medium is a... wait for it... filter.

The dashpot slows the rate at which the throttle body closes at any RPM below 2200RPM. It is on most cars of this vintage; It's not Supra specific and has nothing to do with the Supra's running rich as the Supra doesn't run rich except during open-loop operation (When it's warming up from a cold start or at >70% throttle)... Also, when decelerating the ECU stops injecting fuel until the RPM are below ~1200RPM.

The last item is the cruise control actuator; Should be obvious when that's active. It works by pulling on that second throttle cable which runs to the linkage assembly.