I have an aftermarket TBI on my crate 350 with 61# injectors. I am monitoring the mixture with a air/fuel ratio gauge and it isn't even registering on the gauge when I am on the highway. (it is all the way to the bottom on the lean side). It bounces up and down when it idles and it goes to normal when I let off of the gas or give it gas. I have a afpr, how can I make the tbi run richer?

 

You need to datalog to find out if you are really lean. Those gages are finiky at best and can only give you some detail on WOT fueling. They are not accurate at part throttle or cruise RPM's because your O2 volts are constantly changing. I would start by upping the FP a bit on your regulator.

 

CAN YOU EXPLAIN WHAT TO LOOK FOR ON DATALOG FOR wot a/f? I WAS OF OPINION ALDL DOES NOT PROVIDE ANY FEEDBACK IN PE WHICH IS OPEN LOOP. 02 volts does tell you if going lean/rich for that point in time does it not? that is when ae or pe invoked does not the 02 volts drop if enriched? please give me a little input on this.

 

Look at your BML's. You want them to be around 128. Some more advanced burners will chime in.

 

If its registering lean while you're cruising on the highway your calibration may not be lean, highway mode might just be kicking in. You want to test for it while driving around town at different RPM but lower speeds so it doesn't go into PE or highway mode (if its enabled). Log your BLM's off of that kind of driving.

 

Shifty: i am of opinion PE A/F ratio cannot be determined by daatalogging. i had mine set in eprom to commanded 12/1. on dyno it showed 11.9/1 and 12.1/1. so i must have had VE tables ok. now i moved the commanded to 12.5. WB02 will confirm in about 3 weeks if lucky. i believe if VE tables accurate all else falls into place.

 

Well, I have been avoiding getting the winaldl program and the cable made. I guess it is getting inevitable now. I will play with the afpr but what exactly is PE mode or highway mode???

 

Win ALDL will not help you WOT. You have three options, first being the stab-in-the-dark method where you change your WOT tables and then run and see what happens. Second being buying/building a wideband O2 sensor and plugging that in, seeing how rich/lean you are, third would be dyno'ing it with a wide band O2 and going from there.

 

It's fine at WOT. It's highway cruising speed is when it is running lean bad. Around town it is fine too.

 

I think this is like the first line in all of your responses now.

 

PE mode is power enrichment mode, its where the computer adds more fuel to to the mixture. At x% throttle the computer triggers it. A narrow band gague is not really useful for monitoring rich/lean. Your best bet is getting winaldl up and running, that'll help ya out seeing where your problem is.

 

I know but it really is the only way to go to understand what your car is doing when you add mods.

 

lean at hwy/OK at WOT? i think WOT accuracy can only be determined after the cruising BLM's are optimized. they need to be accurate as PE /WOT relates to that as a basis. we start tuning at idle and work our way up gradually after datalogging and taking notes.