Low RPMs bucking - Page 7 - ZR-1 Net Registry Forums

XfireZ51 · 05-19-2016

Quote:

Originally Posted by MuRCieLaGo

Put my hand near the flanges/clamps and I felt some air.

I really need to do some researches regarding that closed loop thingy. I'm not sure I understand how it works.

Thanks a lot for your help.

Closed Loop means that the ECM is using O2 sensors as one of the inputs for calculating injector pulse width. The VE tables are the main fueling tables and then the ECM utilizes O2 sensors to modify those values. There's more to it but this is the basic operation.

MuRCieLaGo · 05-21-2016

Small update today:

Been running with the car, knocking noise seems to be GONE since I changed the spark plugs...

New code showed up once today:

Code 42 - Electronic Spark Control Error.

MuRCieLaGo · 05-25-2016

Exhaust leak fixed - no change at all.

Gonna order two new o2 sensors.

MuRCieLaGo · 05-31-2016

Receiving two NGK NTK o2 sensors tomorrow. Meanwhile, car developped another symptom: stalls randomly at red lights (starts perfect when I crank it back).

XfireZ51 · 05-31-2016

Could you recap the changes you made prior to all this happening?

MuRCieLaGo · 05-31-2016

Quote:

Originally Posted by XfireZ51

Could you recap the changes you made prior to all this happening?

Good idea

RECAP

Problem: low rpm bucking, especially when cold. Stalling at red lights (restarts like a charm). Got codes 55 and 64 once, erased them and they never came back. Also experienced a strange knocking/rattling noise, which went away on its own.

-Electrically tested the injectors, hot. Got between 17.3 and 17.9 ohms everywhere.
-Spark plugs changed.
-Fuel pumps removed, visual inspection done: nothing was wrong.
-Fuel pressure tested. Idle: 41 psi, FP1: 46 psi, FP2: 48 psi.
-Fuel filter changed.

Receiving two NGK NTK o2 sensors tomorrow.

LGAFF · 06-01-2016

I think you have a bent DIS PIN

MuRCieLaGo · 06-01-2016

Quote:

Originally Posted by LGAFF

I think you have a bent DIS PIN

I searched and I found this thread, which shows the connector. However, where is that connector?

http://www.zr1.net/forum/showthread.php?t=20184

Should be easy to check?

LGAFF · 06-01-2016

under the plenum at the back of the intake

MuRCieLaGo · 06-01-2016

So...

1. Change both o2 sensors.
2. Remove plenum and check for that connector.

Should I check something else while the plenum is removed?

05-21-2016	#62
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Re: Low RPMs bucking Small update today: Been running with the car, knocking noise seems to be GONE since I changed the spark plugs... New code showed up once today: Code 42 - Electronic Spark Control Error.

05-25-2016	#63
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Re: Low RPMs bucking Exhaust leak fixed - no change at all. Gonna order two new o2 sensors.

05-31-2016	#64
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Re: Low RPMs bucking Receiving two NGK NTK o2 sensors tomorrow. Meanwhile, car developped another symptom: stalls randomly at red lights (starts perfect when I crank it back).

05-31-2016	#65
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,709	Re: Low RPMs bucking Could you recap the changes you made prior to all this happening? __________________ [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

06-01-2016	#67
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Low RPMs bucking I think you have a bent DIS PIN __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

06-01-2016	#69
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Low RPMs bucking under the plenum at the back of the intake __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

06-01-2016	#70
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Re: Low RPMs bucking So... 1. Change both o2 sensors. 2. Remove plenum and check for that connector. Should I check something else while the plenum is removed?