Running lean???

[friendlyguy64]

So I just installed a LR 60-1, #55 injectors, 3bar fpr, 951 maxchips (Curently have the 951 max chip dme and autothority klr until the new klr chip comes in). I just installed the split second arm1(garbage i know) Well when I turn on the car it starts into yellow then quickly red and steady. I have not driven the car out of the garage because Im scared of detonation. How do I know if the cheap afr is accurate or if my car is actually lean?

[nynor]

unplug the O2 sensor from the DME. see if your A/F ratio goes lower. mine tends to read a bit lean at idle, but on any boost it enriches to 11:1. i leave my O2 sensor unplugged from the DME, except for smog testing.

[Techno Duck]

Try one of the three;

Unplug DME temp sensor
Unplug O2 sensor
Remove and plug vacuum line to the fuel pressure regulator

Any of these three will cause the car to run rich and should change the reading. Another option is on cold starts, the gauge should read rich.. this is because the car will idle at around 11.8AFR, then as the engine warms up will progressively lean out to 14.7. This is assuming everything on your car is up to par.

Like i said in the other thread on RL, the ARM1 is a narrowband gauge and really only useful letting you know what the AFR is at idle. As the name implies, its voltage range is so narrow (narrowband is 0-1v, wideband is 0-5v) that small changes in the AFR will only show up as lean or rich. Its not telling how lean or how rich it actually is. What do i mean by this? Well technically anything under 14.7AFR is considered rich.. the narrowband gauge will read rich whether you have an AFR of 14.2 or 10.5. The difference in those is huge, but the narrowband will only make the distinction of it being 'rich'.

You are probably okay to drive the car as long as you stay out of boost. If you are really paranoid you either need to dyno the car with a wideband sniffer in the exhaust or install a wideband O2 and gauge.

[nynor]

i assumed you had a wideband A/F gauge. get one. what techno said.