Sticking secondaries - ZR-1 Net Registry Forums

Flyman 27 · 09-22-2017

Been working on my Z again (more like "still"). Pulled the plenum (with help from -=JEFF=-) to replace the starter and checked out everything else while it was apart. The PVC hose was disintegrated, it fell apart. The large crankcase vent hoses were cracked & hard as a rock (& leaking oil). Cracked & broken vacuum hoses. Loose screws, etc. It was a tad messy in there.

Tried testing the secondaries actuators with my MityVac and the Driver's side tests out perfectly, actuates at 10" and holds. The Pass side was not so perfect. Actuated at 20" vacuum and did not retract when the vacuum was bled off. They had to be retracted by hand. Tried many times & had the same result.

I think I might have a line on a used actuator. Could the sticking actuator be caused by something else? Is there anything else I should be looking over while the area is open? I did find a mouse nest under the starter, is there anything in the secondary actuator system that could be damaged by mice?

Dan

BigIke · 09-22-2017

Remove them bad boys and wire the plates open!

Sent from my SM-G950U using ZR-1 Net Registry mobile app

RussMcB · 09-22-2017

BigIke's suggestion might be the fastest and easiest fix (along with a Haibeck chip).

If you remove the sticking actuator (pretty easy to do IIRC), does the rest of the linkage move freely and not stick? That will help you determine if the problem is with the actuator or not.

Good luck.

XfireZ51 · 09-23-2017

Flyman,

I have spare parts for the secondaries here in Bartlett.

BigIke · 09-23-2017

I rolled with them wired open even before the chip. No issues

Sent from my SM-G950U using ZR-1 Net Registry mobile app

A26B · 09-23-2017

If your secondary port throttles won't close after opening, with the actuator still connected, disconnect the actuator from the linkage & test it again. If you can pull 20" on the actuator, doesn't sound like there's anything wrong with the actuator.

It's more likely that the SPT is not operating freely due to fuel gunk buildup or a bent port throttle shaft. In either regard, it needs to be checked. I've seen the secondary port throttle valves so fouled that it was impossible to move them by hand, let alone vacuum.

Flyman 27 · 09-23-2017

Quote:

Originally Posted by XfireZ51

Flyman,

I have spare parts for the secondaries here in Bartlett.

Took it all apart & cleaned everything very good, it was pretty gunky in there. Reassembled & installed the replacement actuator and everything is loose & working well.
Thank you for all the input and thank you Xfire for offering me your spare parts!

Dan

XfireZ51 · 09-23-2017

Quote:

Originally Posted by Flyman 27

Took it all apart & cleaned everything very good, it was pretty gunky in there. Reassembled & installed the replacement actuator and everything is loose & working well.
Thank you for all the input and thank you Xfire for offering me your spare parts!

Dan

I have more parts if needed. 👌

09-22-2017	#1
Flyman 27 Join Date: Apr 2017 Location: Wayne Illinois Posts: 402	Sticking secondaries Been working on my Z again (more like "still"). Pulled the plenum (with help from -=JEFF=-) to replace the starter and checked out everything else while it was apart. The PVC hose was disintegrated, it fell apart. The large crankcase vent hoses were cracked & hard as a rock (& leaking oil). Cracked & broken vacuum hoses. Loose screws, etc. It was a tad messy in there. Tried testing the secondaries actuators with my MityVac and the Driver's side tests out perfectly, actuates at 10" and holds. The Pass side was not so perfect. Actuated at 20" vacuum and did not retract when the vacuum was bled off. They had to be retracted by hand. Tried many times & had the same result. I think I might have a line on a used actuator. Could the sticking actuator be caused by something else? Is there anything else I should be looking over while the area is open? I did find a mouse nest under the starter, is there anything in the secondary actuator system that could be damaged by mice? Dan __________________ 91-#1935 Black/black & gray, Haibeck 500 Cams by Pete Last edited by Flyman 27; 09-22-2017 at 09:12 PM.

09-22-2017	#2
BigIke Join Date: Aug 2014 Location: Montgomery TX Posts: 263	Re: Sticking secondaries Remove them bad boys and wire the plates open! Sent from my SM-G950U using ZR-1 Net Registry mobile app __________________ 1991 White ZRJuan #1616 Mileage: 56K Sept-14 -- 113k May-18!!! God Damn I Love This Car!

09-22-2017	#3
RussMcB Join Date: Jan 2015 Location: Marietta, GA USA Posts: 1,160	Re: Sticking secondaries BigIke's suggestion might be the fastest and easiest fix (along with a Haibeck chip). If you remove the sticking actuator (pretty easy to do IIRC), does the rest of the linkage move freely and not stick? That will help you determine if the problem is with the actuator or not. Good luck. Last edited by RussMcB; 09-23-2017 at 10:36 AM.

09-23-2017	#4
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,702	Re: Sticking secondaries Flyman, I have spare parts for the secondaries here in Bartlett. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

09-23-2017	#5
BigIke Join Date: Aug 2014 Location: Montgomery TX Posts: 263	Re: Sticking secondaries I rolled with them wired open even before the chip. No issues Sent from my SM-G950U using ZR-1 Net Registry mobile app __________________ 1991 White ZRJuan #1616 Mileage: 56K Sept-14 -- 113k May-18!!! God Damn I Love This Car!

09-23-2017	#6
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,393	Re: Sticking secondaries If your secondary port throttles won't close after opening, with the actuator still connected, disconnect the actuator from the linkage & test it again. If you can pull 20" on the actuator, doesn't sound like there's anything wrong with the actuator. It's more likely that the SPT is not operating freely due to fuel gunk buildup or a bent port throttle shaft. In either regard, it needs to be checked. I've seen the secondary port throttle valves so fouled that it was impossible to move them by hand, let alone vacuum. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.