Wide Open Throttle - Open Loop criteria - ZR-1 Net Registry Forums

richarde · 10-04-2020

I would appreciate a little help.
I have an ALDLDroid and have recently been road testing it on my black 1990 ZR-1. On wide open throttle, the ALDLDroid info states that the car is still on closed loop, although the car performs / accelerates really strongly. I believe that the criteria for the car going from closed loop to open loop on WOT include: battery voltage, coolant temp, intake air temp, intake air temp, MAP and TPS. Does anyone have the criteria (in figures) that has to be met before going on open loop?
Thanks

Corvette95 · 10-04-2020

You may be confused...when you start the car cold...it is in OPEN loop, as the temps warm up (this is not exact just from memory) the water temp is above 140 and oil above 100 it switched to CLOSED loop which the ECM takes over fuel management. Also, I believe the secondaries will not function with a stock PROM in open loop.

richarde · 10-04-2020

I don't think I'm confused - According to my reference books, it switches back to open loop on WOT.

-=Jeff=- · 10-04-2020

No. Open loop is while the car is cold. Once it hits the requirements for closed loop it switches. While cruising around part throttle Learn mode is on. When it goes the WOT the car is in closed loop but Learn Mode is off. It uses set parameters and does not learn and change anything during WOT somewhat similar to open loop

richarde · 10-04-2020

Thanks for the clarification Jeff. I was getting my info from the Corvette Fuel Injection and Electronic Engine Management manual, which is obviously incorrect. Thanks again

-=Jeff=- · 10-07-2020

Looking through a couple scans again I gave misinformation WOT does go into open loop. I was going off of memory from my last data log over the summer. When I looked at my display I had removed the Open/closed indicator part way through logging and swapped it with Learn mode on and off.

Sorry about that

10-04-2020	#1
richarde Join Date: Sep 2012 Location: United Kingdom Posts: 68	Wide Open Throttle - Open Loop criteria I would appreciate a little help. I have an ALDLDroid and have recently been road testing it on my black 1990 ZR-1. On wide open throttle, the ALDLDroid info states that the car is still on closed loop, although the car performs / accelerates really strongly. I believe that the criteria for the car going from closed loop to open loop on WOT include: battery voltage, coolant temp, intake air temp, intake air temp, MAP and TPS. Does anyone have the criteria (in figures) that has to be met before going on open loop? Thanks __________________ Richard 1990, numbers 1821 and 2391 1821 - owned since Nov 2002, charcoal / Gray, Stainless headers, B&B system, 4.10's 2391 - owned since Jan 2019, Black / Black, have completed restoration. Jeal headers, Corsa system, 4.10's, Aluminum flywheel with Carolina clutch.

10-04-2020	#2
Corvette95 Join Date: Jan 2006 Location: Decatur, AL Posts: 1,119	Re: Wide Open Throttle - Open Loop criteria You may be confused...when you start the car cold...it is in OPEN loop, as the temps warm up (this is not exact just from memory) the water temp is above 140 and oil above 100 it switched to CLOSED loop which the ECM takes over fuel management. Also, I believe the secondaries will not function with a stock PROM in open loop. __________________ Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454

10-04-2020	#3
richarde Join Date: Sep 2012 Location: United Kingdom Posts: 68	Re: Wide Open Throttle - Open Loop criteria I don't think I'm confused - According to my reference books, it switches back to open loop on WOT. __________________ Richard 1990, numbers 1821 and 2391 1821 - owned since Nov 2002, charcoal / Gray, Stainless headers, B&B system, 4.10's 2391 - owned since Jan 2019, Black / Black, have completed restoration. Jeal headers, Corsa system, 4.10's, Aluminum flywheel with Carolina clutch.

10-04-2020	#4
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,165	Re: Wide Open Throttle - Open Loop criteria No. Open loop is while the car is cold. Once it hits the requirements for closed loop it switches. While cruising around part throttle Learn mode is on. When it goes the WOT the car is in closed loop but Learn Mode is off. It uses set parameters and does not learn and change anything during WOT somewhat similar to open loop __________________ 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

10-04-2020	#5
richarde Join Date: Sep 2012 Location: United Kingdom Posts: 68	Re: Wide Open Throttle - Open Loop criteria Thanks for the clarification Jeff. I was getting my info from the Corvette Fuel Injection and Electronic Engine Management manual, which is obviously incorrect. Thanks again __________________ Richard 1990, numbers 1821 and 2391 1821 - owned since Nov 2002, charcoal / Gray, Stainless headers, B&B system, 4.10's 2391 - owned since Jan 2019, Black / Black, have completed restoration. Jeal headers, Corsa system, 4.10's, Aluminum flywheel with Carolina clutch.

10-07-2020	#6
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,165	Re: Wide Open Throttle - Open Loop criteria Looking through a couple scans again I gave misinformation WOT does go into open loop. I was going off of memory from my last data log over the summer. When I looked at my display I had removed the Open/closed indicator part way through logging and swapped it with Learn mode on and off. Sorry about that __________________ 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