Non-operating Secondaries Repaired - ZR-1 Net Registry Forums

QB93Z · 07-06-2009

Ever since I bought the yellow 1994 ZR-1 back in May, the engine at full throttle felt weak and "surged".

Using a Tech I, I determined that the secondaries would open and then shut again after a few seconds and a code 61 would be set. One of the causes of code 61 is when the secondary actuator solenoid is energized but secondary vacuum drops too low. When this happens the system shuts the secondaries.

I finally had time to pull the plenum and track down the problem and correct it. It turned out to be: 1 a vacuum leak in the secondary actuator vacuum system, 2 a bad secondary vacuum check valve, and, 3 a frozed vacuum pump.

The vacuum leak was caused by a replacement check valve (on the left below) somebody installed that had the inlet tubes too small to hold the rubber connectors:

I bought the replacement check valve at Advance Auto Parts for about $3.50. It is made by Dorman.

The vacuum pump appeared to have gotten wet inside (I pryed the cover off to see if it was repairable) and was frozen. I replaced the pump by ordering from Sport Chevrolet using the replacement part number I found here on the NetRegistry Forum (94669091). The pump is a prefect direct replacement for the OEM part:

After putting everything back together, the secondaries seemed to work once, but then failed to stay open again. Trouble shooting with a vacuum gauge indicated a bad check valve.

So, another plenum pull to replace the brand new check valve.

Now everything works great. The car finally pulls hard like a ZR-1 should!

Jim

Jagdpanzer · 07-06-2009

Well done Jim! and thanks for sharing.

FU · 07-07-2009

Tough fix. Glad to hear the car is running fine

Scrrem · 07-07-2009

Wow Jim....You are DA MAN!!!

Rich

ZZZZZR1 · 07-07-2009

Quote:

Originally Posted by Scrrem

Wow Jim....You are DA MAN!!!

Rich

I agree....

secondchance · 07-07-2009

Good to know vacuum pump is still available.
Thanks.

Kb7tif · 07-07-2009

Its pretty rewarding fixing this stuff isn't it.

On mine I had a Bad throttle linkage.

GOLDCYLON · 07-07-2009

Great post up Jim.

How much was that pump. Maybe its time for a spare in the parts crib. GC

QB93Z · 07-07-2009

Quote:

Originally Posted by GOLDCYLON

Great post up Jim.

How much was that pump. Maybe its time for a spare in the parts crib. GC

GC, The pump cost ~$140. I bought the pump from Sport Chevrolet in Silver Spring, MD. They have a great Parts Department there. John C. is one of the parts guys who spends a lot of time helping us track down parts. We also get a "club price" but I don't know how special the deals are.

BTW, My Quasar Blue 1993 was originally sold at Sport Chevrolet, so I feel like it is homecoming everytime I drive down there.

Jim

tomtom72 · 07-07-2009

Nice fix, Jim!

On that vac pump that went bad. Mine went bad also so I bought that pump and was going to have to cut the OE plug off to use the new pump. I took my pump apart as it had seized up solid, and the overload heated up the plastic plug enough to transfer plastic onto the spade terminals & still didn't blow the fuse!

Anyway, they are simple and mine fell victum to water thru the air intake. I used a long hose and added a filter and made a loop in the hose to trap water. I check it every month and so far no water. I think the filter, facing down, has done the trick. It's been about two seasons of use and so far so good. The motor responds well to contact cleaner and a rust penetrator and a toothbrush. I had to clean the grooves in the commutator as they really were packed with rust. They are repairable if you don't mind spending some time. To make it easier to work on the motor parts, I unsoldered the power leads to the brush block & the pressure switch. Just thought I'd throw this out there for anyone who might be curious.

sorry for the hi-jack Jim!

Tom

07-06-2009	#1
QB93Z Join Date: May 2007 Location: Westminster, Maryland Posts: 3,684	Non-operating Secondaries Repaired Ever since I bought the yellow 1994 ZR-1 back in May, the engine at full throttle felt weak and "surged". Using a Tech I, I determined that the secondaries would open and then shut again after a few seconds and a code 61 would be set. One of the causes of code 61 is when the secondary actuator solenoid is energized but secondary vacuum drops too low. When this happens the system shuts the secondaries. I finally had time to pull the plenum and track down the problem and correct it. It turned out to be: 1 a vacuum leak in the secondary actuator vacuum system, 2 a bad secondary vacuum check valve, and, 3 a frozed vacuum pump. The vacuum leak was caused by a replacement check valve (on the left below) somebody installed that had the inlet tubes too small to hold the rubber connectors: I bought the replacement check valve at Advance Auto Parts for about $3.50. It is made by Dorman. The vacuum pump appeared to have gotten wet inside (I pryed the cover off to see if it was repairable) and was frozen. I replaced the pump by ordering from Sport Chevrolet using the replacement part number I found here on the NetRegistry Forum (94669091). The pump is a prefect direct replacement for the OEM part: After putting everything back together, the secondaries seemed to work once, but then failed to stay open again. Trouble shooting with a vacuum gauge indicated a bad check valve. So, another plenum pull to replace the brand new check valve. Now everything works great. The car finally pulls hard like a ZR-1 should! Jim

07-06-2009	#2
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,649	Re: Non-operating Secondaries Repaired Well done Jim! and thanks for sharing.

07-07-2009	#3
FU Join Date: Mar 2004 Location: Found Member Posts: 4,327	Re: Non-operating Secondaries Repaired Tough fix. Glad to hear the car is running fine

07-07-2009	#4
Scrrem Join Date: Feb 2009 Location: Alexandria, Virginia Posts: 1,453	Re: Non-operating Secondaries Repaired Wow Jim....You are DA MAN!!! Rich __________________ 1990 Bright Red Coupe #608 380 Stroker, Ported Heads/Intake/Housings/TB Haibeck Secondary Delete Chip / Pete's Cams George Braml Intake / FIC Injectors Coated SW Headers / Corsa Bill Boudreau B/B ZF6 / Viper 4.10 gears Ron Davis Radiator Pioneer AVIC-Z140BH NAV Fikse FM5's 285 / 335 / C6 Brakes WAZOO Member

07-07-2009	#6
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,730	Re: Non-operating Secondaries Repaired Good to know vacuum pump is still available. Thanks.

07-07-2009	#7
Kb7tif Join Date: May 2009 Location: S Nevada Posts: 351	Re: Non-operating Secondaries Repaired Its pretty rewarding fixing this stuff isn't it. On mine I had a Bad throttle linkage. Last edited by Kb7tif; 07-07-2009 at 10:55 AM.

07-07-2009	#8
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,117	Re: Non-operating Secondaries Repaired Great post up Jim. How much was that pump. Maybe its time for a spare in the parts crib. GC __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 07-07-2009 at 11:29 AM.

07-07-2009	#10
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Re: Non-operating Secondaries Repaired Nice fix, Jim! On that vac pump that went bad. Mine went bad also so I bought that pump and was going to have to cut the OE plug off to use the new pump. I took my pump apart as it had seized up solid, and the overload heated up the plastic plug enough to transfer plastic onto the spade terminals & still didn't blow the fuse! Anyway, they are simple and mine fell victum to water thru the air intake. I used a long hose and added a filter and made a loop in the hose to trap water. I check it every month and so far no water. I think the filter, facing down, has done the trick. It's been about two seasons of use and so far so good. The motor responds well to contact cleaner and a rust penetrator and a toothbrush. I had to clean the grooves in the commutator as they really were packed with rust. They are repairable if you don't mind spending some time. To make it easier to work on the motor parts, I unsoldered the power leads to the brush block & the pressure switch. Just thought I'd throw this out there for anyone who might be curious. sorry for the hi-jack Jim! Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member