secondary port throttle solenoid - ZR-1 Net Registry Forums

mavhou · 10-24-2005

Hi,
I have a 1990 and am having the typical vacuum problems after a backfire. I have traced the leak to the secondary port throttle actuator solenoid. Thanks to all of your posts, I was able to get info on it as the local chevy dealers are zr1 idiots. Anyway, I just picked up the new part (1997222) and it had a vacuum port on the back side which my old one does not. Is this a revision with the later models? Do I simply plug it or should i T it into the vacuum system. If I Tee it in, should it be before the solenoid or past? Thanks for all the help. This is a great source of info and you guys do a great job.

mavhou

tomtom72 · 10-25-2005

Hi mavhou, The solenoid that you bought has a shiny metal vacuum port on one end and the black plastic ports, for the vacuum hose assembly, on the other end??

The vacuum hose assembly has the squarish, notched connector made from hard looking rubber or plastic? That connector goes to the black plastic vacuum ports on the rear of the solenoid and the metal port is for the air filter which points toward the front of the motor. Is that what you are talking about??

I'll go look at my old stuff but it sounds like you got the solenoid that used the round barrel-like foam air filter vs. the solenoid that used the flat, squarish foam air filter. Either way the vacuum hose connector goes on one end and the filter goes on the metal port. Let me know what's up as I still have my old stuff & I can go eye it & maybe I can help you out.

Tom

mavhou · 10-25-2005

Thanks for responding. Everything you asked in your post is correct. So now I have to find a filter. Any ideas? Can one be made easily enough. It took the chevy dealer a week to get the solenoid.

Thanks again,

chris
mavhou@yahoo.com

tomtom72 · 10-26-2005

Hi Chris, Good I'm glad we are on the same page! I took one of those Foam wax applicators that came with one of the prods I use for detailing and cut it up to make a cylinder about 1 1/2" in dia by about 2" thick. I tested various foams I had laying around by sucking thru them to find a low resistance one. It turned out to be something I got from Autopia, a generic foam applicator. Then I found a short lenght of vacuum hose to fit the metal port on the solenoid. I didn't know exactly what the OEM filter looks like so I winged it. I made the hose long enough to have a gentle bend, no kinks, over the top of the solenoid back towards the rear of the motor, just past the vac. tank so it was laying on top of the "official vacuum hose assembly".

Next I made a hole in my "filter", not all the way thru but about 1/2 way and used some rtv permatex blue to "glue" the hose into the hole I had made. Just put the rtv on the sides of the hose & let it set up & it worked as far as holding and it allowed air thru the hose! I stuck it on the solenoid & I know it's a bit rediculous looking but I think it works because my secondaries work!

Tom

mavhou · 10-26-2005

thanks for helping out. I think I'll rig up something myself, also; your formula sounds good. I think I'll give it a try with a similar setup. At least the vacuum leak is fixed and I can be back on the road soon.

Thanks again,

chris

tomtom72 · 10-26-2005

Chris! Good luck with the fix. I know my "filter" is not elegant but I think it works.

Tom

10-24-2005	#1
mavhou Join Date: Oct 2005 Location: Houston area Posts: 3	secondary port throttle solenoid Hi, I have a 1990 and am having the typical vacuum problems after a backfire. I have traced the leak to the secondary port throttle actuator solenoid. Thanks to all of your posts, I was able to get info on it as the local chevy dealers are zr1 idiots. Anyway, I just picked up the new part (1997222) and it had a vacuum port on the back side which my old one does not. Is this a revision with the later models? Do I simply plug it or should i T it into the vacuum system. If I Tee it in, should it be before the solenoid or past? Thanks for all the help. This is a great source of info and you guys do a great job. mavhou

10-25-2005	#2
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: secondary port throttle solenoid Hi mavhou, The solenoid that you bought has a shiny metal vacuum port on one end and the black plastic ports, for the vacuum hose assembly, on the other end?? The vacuum hose assembly has the squarish, notched connector made from hard looking rubber or plastic? That connector goes to the black plastic vacuum ports on the rear of the solenoid and the metal port is for the air filter which points toward the front of the motor. Is that what you are talking about?? I'll go look at my old stuff but it sounds like you got the solenoid that used the round barrel-like foam air filter vs. the solenoid that used the flat, squarish foam air filter. Either way the vacuum hose connector goes on one end and the filter goes on the metal port. Let me know what's up as I still have my old stuff & I can go eye it & maybe I can help you out. Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

10-25-2005	#3
mavhou Join Date: Oct 2005 Location: Houston area Posts: 3	Re: secondary port throttle solenoid Thanks for responding. Everything you asked in your post is correct. So now I have to find a filter. Any ideas? Can one be made easily enough. It took the chevy dealer a week to get the solenoid. Thanks again, chris mavhou@yahoo.com

10-26-2005	#4
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: secondary port throttle solenoid Hi Chris, Good I'm glad we are on the same page! I took one of those Foam wax applicators that came with one of the prods I use for detailing and cut it up to make a cylinder about 1 1/2" in dia by about 2" thick. I tested various foams I had laying around by sucking thru them to find a low resistance one. It turned out to be something I got from Autopia, a generic foam applicator. Then I found a short lenght of vacuum hose to fit the metal port on the solenoid. I didn't know exactly what the OEM filter looks like so I winged it. I made the hose long enough to have a gentle bend, no kinks, over the top of the solenoid back towards the rear of the motor, just past the vac. tank so it was laying on top of the "official vacuum hose assembly". Next I made a hole in my "filter", not all the way thru but about 1/2 way and used some rtv permatex blue to "glue" the hose into the hole I had made. Just put the rtv on the sides of the hose & let it set up & it worked as far as holding and it allowed air thru the hose! I stuck it on the solenoid & I know it's a bit rediculous looking but I think it works because my secondaries work! Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

10-26-2005	#5
mavhou Join Date: Oct 2005 Location: Houston area Posts: 3	Re: secondary port throttle solenoid thanks for helping out. I think I'll rig up something myself, also; your formula sounds good. I think I'll give it a try with a similar setup. At least the vacuum leak is fixed and I can be back on the road soon. Thanks again, chris Last edited by mavhou; 10-26-2005 at 05:01 PM.