8726 using TunerProRT
454 TBI

I just started WOT tuning, I got my BLMs to 128 in normal driving areas. I than couldn't drop the AFR at WOT, just stays around .600 - .700 volts on the O2. I commanded an 11:1, 10:1, 9:1, 14:1(testing if its backwards) AFRs for PE and basically no change with any of them.

This week I am installing a new fuel filter AND a TPI pump. I added crazy shims in the stock regulator but the pressure wont seem to go over 14 psi. No load reving cause about 1 psi drop.

Am I tuning my WOT AFR wrong or is it my stock pump?

 

I set all my commanded AFRs to 12:1, then just used the VE tables to do WOT.

I would also not use the stock o2, its hard to even get it in the ballpark that way, you really need to get a WBO2.

 

Yeah those readings from your O2 may not even reflect anything correctly about the tune at that point.

It looks like it is most definitely your stock fuel pump. Personally I wouldn't bother with a TPI pump I'd go straight for a Walbro 190 or 255. You can pick up a 190 for about 85 bucks. Do it right the first time and drop the tank only once.

 

Your probably out of pump, but more than likely your injectors are gong static with those really low camanded AFR's.

This is a good read if you can stand to go through the whole thing.

https://www.thirdgen.org/techbb2/sho...hreadid=210908

Really shows how important a WB really is.

 

Yep, I always point out that one of BM's thread to people, it's a really good read with a positive result at the end of it. It also serves as a reminder that RBob knows everything haha

 

Thanks for the replies guys

A wide band is something I do want, but its not going to happen anytime soon. For now I would perfer .900 over .600 on the O2.

I am planning on doing that pump tomorrow. I am not worried about changing out pumps more than once because I am doing an access hole.