03-19-2020 | #1 |
Join Date: Feb 2020
Location: Moorestown NJ
Posts: 5
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Secondary Port Throttle Vacuum motor
This is my first post and I am glad to be a member and owner of a 94 ZR1
I noticed I was having slightly higher than spec'd idle rpm. 900-1000. display noted some issue. I looked at the post by Marc Haibeck and I checked to see if my vacuum motor turned on immed after keyed to ON position. No sound at all. It was gettin 12vdc. I took the motor out and bench tested it and it didn't work. Took it apart (see 2nd image) and it was fried. looks like water got into it from the white inlet inlet nipple. I ordered a replacement but I need some advise as I think I have a better way of routing the inlet air via a hose higher up in the area with a modified protector so water cant get in. Your suggestions are welcome |
03-19-2020 | #2 |
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,852
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Re: Secondary Port Throttle Vacuum motor
The reason it’s fried is more likely you have a vacuum leak in the secondary system which allowed the pump to run continuously and burn out. When you install the new one make sure it cycles on a off as it should with just the key on and off when the engine is idling. The motor on these is sealed and shouldn’t be affected by water, only the connections are susceptible to corrosion.
H
__________________
90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold. Last edited by Ccmano; 03-19-2020 at 07:35 PM. |
03-19-2020 | #3 |
Join Date: Aug 2015
Location: Magnolia, Texas
Posts: 884
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Re: Secondary Port Throttle Vacuum motor
Hans is on it. The hint is that your idle is high, suggesting a vacuum leak..
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03-20-2020 | #4 | |
Join Date: Feb 2020
Location: Moorestown NJ
Posts: 5
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Re: Secondary Port Throttle Vacuum motor
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03-20-2020 | #5 | |
Join Date: Feb 2020
Location: Moorestown NJ
Posts: 5
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Re: Secondary Port Throttle Vacuum motor
Quote:
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03-20-2020 | #6 |
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,852
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Re: Secondary Port Throttle Vacuum motor
Now go over to the driver side of the plenum and pull the vacuum line from the center and plug the line with a small bolt, golf tee or some such. Then go back and do your vacuum test again in the same place as before. If vacuum holds your check valve (under the plenum) is bad, if it still drops you have a leak elsewhere in the secondary system. If you can stand there and watch the vacuum gage go down the leak is substantial enough.
H
__________________
90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold. |
03-25-2020 | #7 |
Join Date: Mar 2019
Location: Colorado - Denver
Posts: 22
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Re: Secondary Port Throttle Vacuum motor
So I just looked at my 93 zr1 and I don’t have anything coming off my white tube either. It looks just like yours in the picture. Should something be connected to the white tube on the vacuum pump and if so where should it go. I don’t think mine shuts off either but my idle and secondaries work fine. Thanks for any input here as well.
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03-25-2020 | #8 | |
Join Date: Feb 2020
Location: Moorestown NJ
Posts: 5
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Re: Secondary Port Throttle Vacuum motor
Quote:
My thought although I may be wrong is because this white port sits low in the engine compartment it might suck in rain water. I am going to attach some black hose, to it, about a foot or so, shaped in an S configuration , secure it higher up. I am going to check some additional vacuum connections as suggested by CCmano |
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