A few misc. questions

[MisterTurbineTwister]

There are a few things that are bothering me with my '88 Turbo 5 speed targa car and I'd like to know a few things from other experienced MKIII owners.

1. I have little to no heat coming out of my heater core. I have replaced the fan clutch, the temp sensor and the thermostat when I replaced the HG about 8 months ago. The engine runs great and at the correct temperature, but I get no heat.

I know that there is a VSV that controls the vacuum to the heater's bleed valve, but I had to replace some of the faulty connections with a few connectors (including this VSV connector) under the hood along with someone elses electrical tape and pocket knife "wiring harness" fix. I have not had any electrical problems with the engine after I went through the harness and soldered and heat shrink wrapped the previous fixes.

The vacuum servo and linkage to the valve move when it's supposed to, but I don't know if it's moving correctly. Which direction does the linkage on the firewall move when the valve should be open?

I know that the VSV is supposed to send vacuum to the heater servo unit under closed electrical circuit, but is this VSV switch polar sensitive? I don't think it is, due to it's on/off operating nature, but I'd just like another opinion.

2. The power steering system just started leaking. Do these pumps have any typical leak in them after high milage? I'm thinking that it's the pressure hose that goes from the pump to the rack, but I was just asking to see if the pumps in these cars typically the cause of the leak or if I am on the right track with the pressure line.

The pump is $85 and the line is about $75-80. I can afford to replace one or the other at the moment, but I'd hate to waste my money on a part that didn't need replacing and not fix the problem. I will eventually replace the pump and hose and I will replace the return hose no matter what because it's cheap and I might as well since the pump and other lines will be off. I know that these pumps use automatic transmission fluid and it was only using a small amount before yesterday. I can't drive the car until it's fixed.

Thanks for the help in advance!

 

[s turbo 87]

I would try replacing the high pressure hose before the pump. The pump usually doesnt leak.

 

[MisterTurbineTwister]

That's good to know. Thanks.

Is there a moderator that can move this to the tech section? I don't know if this should be in the FAQ area as they aren't quite frequent questions.

 

[flubyux2]

you need to make sure that the actuator rod for the heater valve is COMPLETELY hidden inside the actuator. its lowered position is about 30* from verticle when at rest. when fully open, the heater valve lever is about 30* from verticle at the top of the travel. if its only resting somewhere inbetween w/ the heat on, then youre valve isnt opening fully andy oure obviously not getting coolant flow

 

[IJ.]

Flub: Any idea how the climate control regulates the heat?

Back in the old days a slider controlled the heater valve opening, not sure how the Supra does it though?

I know when my climate control switch died I had no heat no matter what I did with the firewall valve so I suspect another valve in the system somewhere you can't see.

 

[Jeff Lange]

Thread moved.

 

[Johnny Dangerously]

MrturbineDude...your problem could be your VSV itself is prolly shot. Theres a little rod thats spring loaded. When you turn your heat on, its supposed to move and engage the valve to let coolant in.

sometimes they fuckin blow ass and dont move worth a damn..so you can either get a new VSV or bend that little rod out of its slot and out of its spring tension and physically move it yourself..now youre letting coolant in the core, now you should have some heat.

 

[MisterTurbineTwister]

Thanks for moving the thread, Jeff.

Thanks for the valve operation info fluby. I'll check my setup out in the daylight tomorrow.

Johnny, my VSV does actuate the vacuum circuit, but from what you're saying, will a faulty VSV give some actuation?

I don't quite know how the climate controls work exactly, but from what I can gather from experementation and process of elimination, there is only two positions for the valve to be in due to the nature of a VSV. Full open and full closed. I assume that the climate controls have something to do with air doors allowing more or less air travel from the heater core and another source, blending the two to create the set desired temp.

I'll study the positioning of the linkage and determine if I am getting any vacuum resistance with my vacuum gauge and some T fittings plugged in before and after the VSV. I assume that a good VSV should read the same amount of vacuum before and after the switch when it's on.

Is there a factory VSV test that can be performed, or a better question, should there be any difference in a vacuum gauge readout before and after the VSV when open on a good VSV? I don't think that there would be, but I don't know if Toyota designed the VSV to have any vacuum limiting and I'd hate to throw a good VSV out if it showed some vacuum resistance if there were supposed to be some.