DSF

Ok my A/F guage gives me a nice 14.7-14.0 reading while cruising and 13.2+ while acceraleting. BUT, only with my lights off When I put my parking lights on it reads 1-2 points leaner and with full headlights on, an additional 1-2 points leaner. The O2 sensor "should" be in good working order, so I can only assume it's some sort of electrical interference. I have the gauge mounted in the instument cluster of my 2g CRX, in place of the stock tach. I used in it my last CRX and never had this problem. I'm using the EFI systems dual gauge http://www.efisystems.com/afm.htm I doubt it's actually leaning out because the injector pulse remains fairly constant. My car was a DX and I did have to swap the O2 wire around converting it to MPFI and I didn't use sheilded wire. Any chance of radiated interference getting in the line? My concern is that if my guage is picking up this "lean" condition, the ecu might also. Possibly causing it to actually run rich, or at least try to.

Weird

FYI: I'm running 50psi (no vac) of FP on 450 DSM injectors. I see duty cycles approaching 90% at full tilt. Odd that Honda would allow that much open time with their stock ECUs.


[Modified by DSF, 7:04 AM 4/24/2002]

boosted3g

Sounds like there is a small drop in voltage when you turn the lights on. Time to get out the EVOM

Safir

it is common for a A/F guage to lean out a bar or two when a load is placed on the electrical system (like headlights/stereo) due to a temporary voltage drop in the entire system. the A/F guage is just a volt meter after all. It is nothing to worry about unless it does not pop back immediately.

John_at_J&S

The votage drop is in the ground connection from the headlights to the battery. If a lot of current flows into ground, the voltage on that local "ground" will rise, with respect to the battery ground. So, if the A/F gauge's ground rises, the reading will appear to be lean.

Move the A/F gauge ground wire to a "clean" ground, away from other heavy grounds, or extend it all the way to the battery.

EE_Chris

I would perhaps check and clean your grounds, escpecially the ones associated with your lighting.

Remember, just because your hear "GND"....do not assume 0V.

VTC_CiViC

I know my AM A/F gauge has always gone a few bars leaner when I use my lights, doesn't "pop" back up to normal either, unless I turn off my headlights. Hell when I'm sitting at a light and my fan clicks on, I go lean too..

Damn I need my AGT gauge installed

DSF

Exactly what mine does. Althought the fan doesn't affect mine. And I have my EGT installed

Thanks for the suggestions everyone I'll check all my grounds tonight and relocate them if necessary. Hopefully that should help.

Slater

...I had wierd problems with my A/F gauge when I first installed it. I extended the ground directly to the battery and the problems went away.

- Slater