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89 930.
 
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Question thermo-time switch.

Hi again:

I read somewhere that the "thermo-time switch" (Or other name) also controls the idle when the engine is cold. Am i correct in my thinking? Car takes 10 min to idle correctly, Cold pressure and fuel volume are now in spec, but it still has a cold idle issue it never had before.

I have a 1987 930 and wondering where it is and what resistance (or how to test it) i should be getting if it is working right?

If anyone knows ( i cant find it in the shop manual) it would be a great help for me. I don't believe my wur is the issue,but still may be.

It looks like this: Pelican Parts - Product Information: 930-617-118-00-OEM


Or possibly this: Pelican Parts - Product Information: 930-606-117-00-M100

Last edited by Benny771; 07-30-2011 at 10:12 AM..
Old 07-30-2011, 10:09 AM
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This thread explains the placement, workings and testing of the thermo time switch:

930-78-3,3 thermo time switch ??
Old 07-30-2011, 10:26 AM
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Thanks, ive read that one.
Im looking for the switch that controls the idle somehow untill it engine reaches norm temps
?? Temperature Sensor??? Possibly ??
The post i read , the guy had the same idle issue as me and he thought it was the WUR as well. but it wasnt, he used a ohm meter on it and it was out of spec, changed it, problem solved. 10 min time frame to idle right.
Now i cant find that post . If it rings a bell to anyone he had a picture of the sensor/switch on the last post.

Last edited by Benny771; 07-30-2011 at 10:38 AM..
Old 07-30-2011, 10:32 AM
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Ben:

You'll find it to the left of the distributor and down on the upper left side of the chain cover with two wires connected to it.

Cole
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Mods: TurboKraft Custom IC, 934 Headers, GSX 61, Zork, Port Work, SC Cams, Air Mod Fuel Dist Relocated, Water Meth Injection, BL WUR, MSD 6530, Greddy EBC, Synapse Bov, Short 2nd & 3rd with 8:37 R&P, Wevo Shifter, Coupling, and Mounts, MTX-L SSI-4, Big Brakes, Rebel Coilovers, Bilstein Sports.

Last edited by cole930; 07-30-2011 at 11:38 AM..
Old 07-30-2011, 11:35 AM
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There is no electronic connector's on the left side. There is one on the right but only one wire.
It is closed when cold. And appears to be 0 res.

1989 930.
Old 07-30-2011, 12:42 PM
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Benny, the TTS does not control your cold idle...or any idle for that matter. All it does is work in conjunction with an injector to inject fuel direct into the intake manifold for a short period of time, dependent upon engine and sensor temperture, to richen the mixture and facilitate starting. After a few seconds the TTS become inoperative.

If your control pressures at in spec, then look to a malfunctioning AAR. It it isn't opening, or not enough, then you will see a low idle until the engine is warmed up.
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Old 07-30-2011, 01:01 PM
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Ya, did the control pressures, and tested the AAR. I thought the AAR was only used for 1min or so at cold start-up? Mine is like 10min of bad idle.
Going to swap a WUR out to test mine tomorrow. 2hr drive. Is there no other tempature sensor that could do this? Like the two listed in my first post?
Old 07-30-2011, 01:19 PM
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there is a small vacuum switch that blocks vacuum retard going to the distributor to raise idle about 200rpms for about a minute after a cold start in your '87 but there is no switch that raises idle for 10 minutes.

there is an aluminum valve sometimes called the auxilairy air valve to the right of the WUR that bypasses air from the intercooler around the throttle body into the intake manifold to raise idle around 800rpms relatively when it's cold. It slowly closes and idle speed gradually lowers over a mantter of minutes depending on ambient temperature.
i'd guess this device is stuck closed and may be your car's problem.

when it's very cold out the thermal time switch in the left side chain case cover opens the cold start injector under the throttle body while the starter motor is cranking. dwell time for that injector depends on how cold it is and how long and how often the starter motor has been cranking.
it has nothing to do with idle speed.

the other sensor you mentioned is in the right side chain case cover and it disables the lambda emissions system while the motor is cold so it will run stronger and smoother but it doesn't make it idle higher.
Old 07-30-2011, 01:21 PM
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Ben:

Sorry !!!!!! I have one of those 1980 antique, hexed, euro 930's.

Cole
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Old 07-30-2011, 01:56 PM
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Quote:
Originally Posted by cole930 View Post
Ben:

Sorry !!!!!! I have one of those 1980 antique, hexed, euro 930's.

Cole
Not old, beautiful !!
Old 07-30-2011, 02:10 PM
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Quote:
Originally Posted by JFairman View Post
there is a small vacuum switch that blocks vacuum retard going to the distributor to raise idle about 200rpms for about a minute after a cold start in your '87 but there is no switch that raises idle for 10 minutes.

there is an aluminum valve sometimes called the auxilairy air valve to the right of the WUR that bypasses air from the intercooler around the throttle body into the intake manifold to raise idle around 800rpms relatively when it's cold. It slowly closes and idle speed gradually lowers over a mantter of minutes depending on ambient temperature.
i'd guess this device is stuck closed and may be your car's problem.

when it's very cold out the thermal time switch in the left side chain case cover opens the cold start injector under the throttle body while the starter motor is cranking. dwell time for that injector depends on how cold it is and how long and how often the starter motor has been cranking.
it has nothing to do with idle speed.

the other sensor you mentioned is in the right side chain case cover and it disables the lambda emissions system while the motor is cold so it will run stronger and smoother but it doesn't make it idle higher.
Well, lets hope its the WUr then.... I will keep you posted . Im swaping out with an 82 930. That wont be a problem R-I-g-h-t ???
Old 07-30-2011, 02:12 PM
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Quote:
Originally Posted by Benny771 View Post
Well, lets hope its the WUr then.... I will keep you posted . Im swaping out with an 82 930. That wont be a problem R-I-g-h-t ???
Let's hope it's NOT the WUR. You said that your control pressures checked out ok, so the WUR is the last place I would look. Look at the AAR (or AAV, interchangable nomenclature). Do this: Start your car, see the low idle, pinch the hose going to the AAR. If the idle does not drop, then the AAR is not letting enough air into the intake. The reverse would be true if you had too high of an idle....pinching the hose would restrict the air and lower the idle.

Do you have both the cold and warm control pressures documented?
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Old 07-30-2011, 05:47 PM
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NO, just the cold. It runs great when its warm. I guess i should test that as well.
I will try that test when i get back home
Old 07-30-2011, 07:33 PM
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Well,

It does not seem to be the WUR. It ran great on his car. I will recheck the AAR and let you know Mark.: )
Old 07-31-2011, 03:06 PM
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