07-28-2020 | #1 |
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
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Update: Secondary delete: Decel stall on 2ndary delete
A work in progress...
Some experience occasional stalls on deceleration (engine braking) from @ or slightly above 3k rpm in certain conditions. One theory is a faster action sensor may be the answer; perhaps the NTK (A8D1B1 21003 from Rock Auto). Well, they're cheap enough, so I installed a pair of them and put the Z through several ~3500ish to ≈ 1200 rpm decels and experienced NO stalls. Encouraging, but too soon to declare success, just yet. ("One example does not a trend make!") In my case, the issue gets worse with altitude; e.g., happens more frequently as the height above sea level increases. It's been said that the issue stems from the SPT being eliminated results in too much air getting in and upsetting the mixture on decel. Yeah-but...I ain't so sure 'bout that! After all, it's the throttle body controlling the amount of air flow - not the SPTs. And, it only happens on decel/engine braking from higher than normal driving rpm. Well, it is an intriguing quirk, and I'll leave it to the experts to solve. It isn't a big deal except when aggressively romping at higher altitudes especially. But, it would be nice if there was a solution...and initial results with the NTKs IS encouraging!
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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 Last edited by Paul Workman; 07-30-2020 at 06:30 AM. |
07-29-2020 | #2 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,162
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Re: Update: Secondary delete: Decel stall on 2ndary delete
RockAuto PN to look up is 21003. it shows to be for the 90-95 Corvette as well
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
07-29-2020 | #3 |
Join Date: Apr 2007
Location: Northern VA
Posts: 2,658
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Re: Update: Secondary delete: Decel stall on 2ndary delete
According to the NTK web site 21003 are for the ZR-1 DOHC engine and the 21006 are for the base OHV engine.
https://partcat.com/ngk Sent from my iPhone using ZR-1 Net Registry
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Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake |
07-30-2020 | #4 |
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,852
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Re: Update: Secondary delete: Decel stall on 2ndary delete
It's the tune. Mine was doing that and a hesitation at times until Dom and I tuned it out. Smooth as silk now.
H
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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. |
07-30-2020 | #5 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,162
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Re: Update: Secondary delete: Decel stall on 2ndary delete
what was done to tune it out?
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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