Injector Housing Bolts - ZR-1 Net Registry Forums

Beaver's 90ZR1 · 08-21-2021

Can someone please help me. I have a 1990 ZR1 Corvette. I need to know the sequence for tightening the injector housing bolts. I have every manual for the car and can find every bolt tightening sequence for the engine, but CANNOT find the sequence for the injector housing. Thank you.

Locobob · 08-21-2021

I don't see a torque sequence specified for the injector housings in my FSM, just says tighten to 20 ft lbs. I think just starting in the middle and working to the edges is the prudent method.

A26B · 08-21-2021

Just follow general procedure, start in the center, alternate left, then right of center until outer bolts are reached.
I recommend 4 steps to final torque, starting with light snug down in sequence, then 1/2 torque in sequence, then full torque in sequence. final pass at full torque again, in sequence.

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Beaver's 90ZR1 · 08-21-2021

Thank you very much for your help.

Beaver's 90ZR1 · 08-21-2021

Thank you very much for your help. I have another question. The reason I asked is because I have the upper plenum off putting new injectors in. So, I thought while I was in there, I should re-tighten the injector housing bolts. Is this correct? Thanks again.

A26B · 08-21-2021

Yes,good procedure.
Same for the Crankcase Vent Cover Bolts.

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Paul Workman · 08-22-2021

Subject to knowledgeable sources, I found a wide range of torque on my IH bolts. So, after replacing the gaskets (thank you Jerry's Gaskets), I used BLUE LOCKTITE on the threads before torquing the the IH down. On subsequent "visits" under the plenum I have not noticed ANY of the IH bolts loosening up.

And, as result, I think I can recommend the Locktite to secure the IHs (among other parts, e.g., plenum, etc.). YMMV.

Ccmano · 08-24-2021

If the IH bolts are loose then the lower gaskets have shrunk and hardened causing oil to be sucked into the intake. You've gone this far, go ahead and replace the lower IH gaskets as well.
H

08-21-2021	#1
Beaver's 90ZR1 Join Date: Aug 2021 Location: Puyallup, Washington Posts: 15	Injector Housing Bolts Can someone please help me. I have a 1990 ZR1 Corvette. I need to know the sequence for tightening the injector housing bolts. I have every manual for the car and can find every bolt tightening sequence for the engine, but CANNOT find the sequence for the injector housing. Thank you.

08-21-2021	#2
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Injector Housing Bolts I don't see a torque sequence specified for the injector housings in my FSM, just says tighten to 20 ft lbs. I think just starting in the middle and working to the edges is the prudent method. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368 Last edited by Locobob; 08-21-2021 at 03:34 PM.

08-21-2021	#3
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Injector Housing Bolts Just follow general procedure, start in the center, alternate left, then right of center until outer bolts are reached. I recommend 4 steps to final torque, starting with light snug down in sequence, then 1/2 torque in sequence, then full torque in sequence. final pass at full torque again, in sequence. Sent from my iPhone using ZR-1 Net Registry __________________ 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.

08-21-2021	#4
Beaver's 90ZR1 Join Date: Aug 2021 Location: Puyallup, Washington Posts: 15	Re: Injector Housing Bolts Thank you very much for your help.

08-21-2021	#5
Beaver's 90ZR1 Join Date: Aug 2021 Location: Puyallup, Washington Posts: 15	Re: Injector Housing Bolts Thank you very much for your help. I have another question. The reason I asked is because I have the upper plenum off putting new injectors in. So, I thought while I was in there, I should re-tighten the injector housing bolts. Is this correct? Thanks again.

08-21-2021	#6
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Injector Housing Bolts Yes,good procedure. Same for the Crankcase Vent Cover Bolts. Sent from my iPhone using ZR-1 Net Registry __________________ 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.

08-22-2021	#7
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Injector Housing Bolts Subject to knowledgeable sources, I found a wide range of torque on my IH bolts. So, after replacing the gaskets (thank you Jerry's Gaskets), I used BLUE LOCKTITE on the threads before torquing the the IH down. On subsequent "visits" under the plenum I have not noticed ANY of the IH bolts loosening up. And, as result, I think I can recommend the Locktite to secure the IHs (among other parts, e.g., plenum, etc.). *YMMV.* __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

08-24-2021	#8
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Injector Housing Bolts If the IH bolts are loose then the lower gaskets have shrunk and hardened causing oil to be sucked into the intake. You've gone this far, go ahead and replace the lower IH gaskets as well. 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.