How to Check AFR?

Ive installed a SC with a 2.85 pulley on my truck. Ive also got the bullydog tuner and will be installing it today. Id like to check my AFR to make sure the truck is not running lean with the tuner and cause damage. How do I check th AFRs without going to a shop?

 

Scanguage can, think maybe Ultraguage, the data is in the ECU/OBDII, can also get a wireless OBD scanner and a smartphone app. Also the tried and true, install a sensor and guage method.

 

Thanks! What is the normal AFR for a supercharged tacoma?

 

A dedicated wideband?

 

$185 AEM (30-4110) UEGO Air/Fuel Ratio Gauge

http://www.amazon.com/AEM-30-4110-U...d=1416852550&sr=1-1&keywords=AEM+wideband+kit

ARF should be 14.7 for all non boosted engines.

 

Unless the ecu switches to open loop. I think it can get it as low as 13-12.5 or so. Not really sure. I never monitored my AFRs when I was NA.

 

AFR is not always going to be 14.7.

It's common to see it drop under WOT and high RPM's to increase cylinder and head cooling by enriching the mixture. I've seen as low as 10.5-11 though usually not much under 12 under aggressive running on other engines (I haven't measured the taco).

Cruising and light throttle will be 14.7 or close to it most likely.

 

Closed loop operation should always hover around 14.7, give or take a few tenths. Open loop, as mentioned above, will richen the mix to 12.5 or so, give or take a few 1's . Richening the mix at open loop is more of a CYA move to ensure that the engine doesn't lean itself out and start burning internal parts.

 

So correct me if I am wrong, i just want to make sure. Anything below 14.7 is a rich mixture and is fine for the motor while anything above is a lean mix and is bad. An upgrade in the pump should be in order now since i added to sc?

 

You should have a larger fuel pump as well as some form of fuel management to properly fuel the SC. And yes, in general anything below 14.7 is considered "rich" and above is considered "lean". However, with respect to boost, I look at it as anything below 12.5 or so is rich and anything above 12.5 is lean.. So what I am getting at is when you get into boost, you want the AFR to be 12.5 and lower.

 

What year is your truck? You should get the URD 7th injector kit if you have a TRD S/C. It will come with a pump.

 

Ditched the bullydog. It was junk! Thanks for the info guys

 

The AEM in the link above is a great unit. I have one in my tri carb 63 falcon. If you don't want a permanent gauge, there are a few that clip on the tail pipe. Summit, Jegs, etc... have them listed with along with some more tech info on how they operate. As noted above, boosted typically run a bit richer (lower numbers) vs normally aspirated engines.

 

Definitely.. im still runnin rich as hell.

this. I also recommend the AEM.

 

N/A, at OEM fuel pressure, stock ECU, & stock injectors, my engine was still running ~10.8:1 AFR's at WOT. OEM tune is just way to rich. That would be on the richer side for a boosted application. 12.0 - 12.5 is the optimal rich AFR for N/A. Optimal lean would be 13.0:1. For optimal boosted, F/I, 11.0 - 11.5:1. On non ethanol.

 

I need to check my AFR at WOT again.. once the driveshaft is fixed and I can actually get into boost