'85 32v US automatic high idle
09-20-2017, 05:52 PM
#16
Rennlist Member
Doesn't that thermoswitch connect to the vapor recovery emissions? I was recently rerouting vacuum lines...my thermoswitch had a broken nipple, so I have a new one. I'm not sure what you mean by "shift valve" though...
09-20-2017, 06:49 PM
#19
Rennlist Member
Here is the diagram I've been using, which is where I get the terms (#13 & #14).
Again, this is all related to the fact that the idle increases as the engine gets warmer.
If the thermo switch is tight and the lines or components *after* the thermo switch are not, then I can see a vacuum leak getting stronger as the engine warms up, thus increasing the idle speed.
Again, this is all related to the fact that the idle increases as the engine gets warmer.
If the thermo switch is tight and the lines or components *after* the thermo switch are not, then I can see a vacuum leak getting stronger as the engine warms up, thus increasing the idle speed.
09-21-2017, 09:59 AM
#20
Rennlist Member
Apparently they named it "shift valve" just to confuse me 
Yes, that makes sense to me...if that shift valve won't hold vacuum, it seems like that would only show up after the thermoswitch opens. Pretty easy to check by removing the line from the shift valve and plugging it (make sure the line going back to the thermoswitch holds vacuum when cold).
Yes, that makes sense to me...if that shift valve won't hold vacuum, it seems like that would only show up after the thermoswitch opens. Pretty easy to check by removing the line from the shift valve and plugging it (make sure the line going back to the thermoswitch holds vacuum when cold).
10-02-2017, 12:06 PM
#24
Rennlist Member
Thread Starter
I am still getting a list together to order.
The control valve is in the $700 range according to Roger. There were some old posts about how the DFW guys found a cheaper replacement, but according to Rog it did not work out.
I am going to replace the shift valve and see what happens. It is around $37 I think. I will update the thread with results. It will be a week or so.
The control valve is in the $700 range according to Roger. There were some old posts about how the DFW guys found a cheaper replacement, but according to Rog it did not work out.
I am going to replace the shift valve and see what happens. It is around $37 I think. I will update the thread with results. It will be a week or so.
10-04-2017, 03:33 PM
#25
I am still getting a list together to order.
The control valve is in the $700 range according to Roger. There were some old posts about how the DFW guys found a cheaper replacement, but according to Rog it did not work out.
I am going to replace the shift valve and see what happens. It is around $37 I think. I will update the thread with results. It will be a week or so.
The control valve is in the $700 range according to Roger. There were some old posts about how the DFW guys found a cheaper replacement, but according to Rog it did not work out.
I am going to replace the shift valve and see what happens. It is around $37 I think. I will update the thread with results. It will be a week or so.
10-04-2017, 04:13 PM
#26
Inventor
Rennlist Member
Rennlist Member
11-14-2017, 09:54 AM
#28
Race Car
I always wondered how would this effect a boosted 86 if bypassed or or no vacuum due to a bad Thermo switch. I know my 84 Euro is vented to air with the 86 USA is there enough pressue with no vacuum would that force open the shift valve under boost?
11-14-2017, 01:56 PM
#29
Rennlist Member
My 86.5 twin Screw is bi-passed as PKen shows above, no place to run it once SCed anyway.
I have also blocked it all off and Bi-passed it on a NA '85 as a boatload of little black pellets came out of the "Valve" when I went to test it. I figured they came from the Charcoal canister, its still connected just looped back as Ken shows.
Dave K
I have also blocked it all off and Bi-passed it on a NA '85 as a boatload of little black pellets came out of the "Valve" when I went to test it. I figured they came from the Charcoal canister, its still connected just looped back as Ken shows.
Dave K
Last edited by davek9; 04-27-2018 at 12:34 PM.
11-21-2017, 07:41 AM
#30
Rennlist Member
Thread Starter
Shift valve replaced, no change.
Temp II replaced, no change.
Throttle position switch harness replaced (this one was crumbling), no change.
I honestly don't know what else to check or replace. I guess I am going to do a smoke test and/or pressure test with the engine hot. Maybe there is a vac leak showing up only when hot. I have done these tests before cold and didn't find anything, but I am out of ideas.
Temp II replaced, no change.
Throttle position switch harness replaced (this one was crumbling), no change.
I honestly don't know what else to check or replace. I guess I am going to do a smoke test and/or pressure test with the engine hot. Maybe there is a vac leak showing up only when hot. I have done these tests before cold and didn't find anything, but I am out of ideas.