Author Topic: Auto Meter A/F adjustments  (Read 2164 times)

0 Members and 1 Guest are viewing this topic.

Offline gnonyx

  • Turbo Street Modified
  • *****
  • Posts: 505
  • PSI: 0
  • Boost n00b
    • View Profile
Auto Meter A/F adjustments
« on: September 09 2021, 07:01:02 PM »
Hi Steve
Yes I'm back again
I finally finished with the majority home projects, and also the needed GN maintenance stuffs we all did at sometimes:
Welded both headers, front and rear upper lower bushings, coil springs, and upper and lower ball joints.
I also replaced the cam sensor since it was making a ticking noise, and it was idling just a bit rough, and I did had the fuel injectors professionally cleaned.
The engine runs great, but there are some questions I need to ask especially with tuning adjustment.
GM 3" MAF
Translator:
MODE settings: sw1-on, sw2-on, sw3-on, sw4-off
MAF BASE settings: #5
Scanmaster readings:
02-675
AF-04
LB-34
BAT-13.2
LB-34
INT-132
BLM-127
NPH-0
CLT-181
ATS-134
RPM-750
TPS-.42
IAC-25
CC- 48-87
OIL PRES.-22
VAC-16
A/F-15.3-15.7
My question is after driving the A/F goes to 10.2, and my understanding the A/F should be around 10.6-10.8, is this statement true?
Also in case you're wandering about my last statement of the A/F metering
https://youtu.be/rZDyisPxD7E
87 GN T-Top, ScanMaster, hot-wire kit, Full Throttle chips w/ matching 60# injectors, adj. fuel pump, and triple pod gauges w/ AEM A/F gauge, oil pressure gauge, vac/boost gauge, Kenne Belle rear seat brace, upgraded tranny w/ Art Carr pan cover, and a pre-lube oil system.

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: Auto Meter A/F adjustments
« Reply #1 on: September 09 2021, 07:59:07 PM »
First, I don't know what you mean by "after driving".  If you are talking about wide open throttle, then a relatively stock engine with boost under 18 psi or so, probably will run best around 11-11.2 to 1 AF.

At idle, it probably should be around 13.5 or 14 to 1.  

At steady cruise it should be 14 to 15 to 1.

At part throttle, maybe 13.5 to 1
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline gnonyx

  • Turbo Street Modified
  • *****
  • Posts: 505
  • PSI: 0
  • Boost n00b
    • View Profile
Re: Auto Meter A/F adjustments
« Reply #2 on: September 09 2021, 09:26:58 PM »
First, I don't know what you mean by "after driving".  If you are talking about wide open throttle, then a relatively stock engine with boost under 18 psi or so, probably will run best around 11-11.2 to 1 AF.

At idle, it probably should be around 13.5 or 14 to 1. 

At steady cruise it should be 14 to 15 to 1.

At part throttle, maybe 13.5 to 1
Yes at WOT and it a stock engine with about 15-17 boost
This is one of my problem trying to get an correct A/F reading of idling around 13.5 or 14.1
The wastegate lever attached to the turbo elbow during my smoke test was leaking through the wastegate lever arm and I believe the A/F sensor which is located about 7" past the turbo exit of the downpipe and is not getting the full exhaust to get the full A/F reading. Some say not to worry about the leak since once the engine heats up it will seal up, but I'm not sure if that statement is true or not.
87 GN T-Top, ScanMaster, hot-wire kit, Full Throttle chips w/ matching 60# injectors, adj. fuel pump, and triple pod gauges w/ AEM A/F gauge, oil pressure gauge, vac/boost gauge, Kenne Belle rear seat brace, upgraded tranny w/ Art Carr pan cover, and a pre-lube oil system.

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: Auto Meter A/F adjustments
« Reply #3 on: September 09 2021, 09:42:11 PM »
For long life, the sensor should be mounted down by the ac box or further such as under the car
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline gnonyx

  • Turbo Street Modified
  • *****
  • Posts: 505
  • PSI: 0
  • Boost n00b
    • View Profile
Re: Auto Meter A/F adjustments
« Reply #4 on: September 09 2021, 10:42:50 PM »
For long life, the sensor should be mounted down by the ac box or further such as under the car
I also replaced the Auto Meter sensor since it been installed for over 10 years ago.
The reason why I installed around 7" since the Auto Meter A/F manual stated the following:
The heated oxygen sensor comes with a stainless steel weld-in bung, plug, and wiring harness with a weather pack connector. The oxygen sensor should be installed as close to the cylinder head as is reasonably possible so that the sensor reaches operating temperature quickly. If long tube headers are used, the oxygen sensor should be installed in the collector. If cast iron manifold(s) or shorty headers are used, install the sensor in the pipe just below the manifold. In multi-bank applications mounting in the left or right side is acceptable. Turbocharged applications should have sensor installed 4-5" after turbo on the down pipe.
87 GN T-Top, ScanMaster, hot-wire kit, Full Throttle chips w/ matching 60# injectors, adj. fuel pump, and triple pod gauges w/ AEM A/F gauge, oil pressure gauge, vac/boost gauge, Kenne Belle rear seat brace, upgraded tranny w/ Art Carr pan cover, and a pre-lube oil system.

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: Auto Meter A/F adjustments
« Reply #5 on: September 09 2021, 10:56:55 PM »
AEM-30-4100_inst.pdf

Everything I have read says 18" on turbos
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline gnonyx

  • Turbo Street Modified
  • *****
  • Posts: 505
  • PSI: 0
  • Boost n00b
    • View Profile
Re: Auto Meter A/F adjustments
« Reply #6 on: September 09 2021, 11:18:16 PM »
AEM-30-4100_inst.pdf

Everything I have read says 18" on turbos
I did found the PDF and it did claimed 18", On page #7 it reads on the bottom of the page of 18" mounting location, and on page #8 it reads on turbocharged engines the UEGO sensor must be installed after the turbocharger, if not, the pressure differential will greatly effect the accuracy of the unit.

https://www.manualslib.com/manual/1301865/Aem-30-4100.html?page=7#manual
https://www.manualslib.com/manual/1301865/Aem-30-4100.html?page=8#manual
I'm just trying to get some guidance direction for this Auto Meter A/F sensor mounting location
Attached is the manual I received with the A/F gauge
87 GN T-Top, ScanMaster, hot-wire kit, Full Throttle chips w/ matching 60# injectors, adj. fuel pump, and triple pod gauges w/ AEM A/F gauge, oil pressure gauge, vac/boost gauge, Kenne Belle rear seat brace, upgraded tranny w/ Art Carr pan cover, and a pre-lube oil system.

 

SimplePortal 2.3.7 © 2008-2024, SimplePortal