Hey all,

Any thoughts are appreciated. I am stumped.

I have Venom injectors rated for 40 lb, FYI and the BLM's at idle and part throttle are pretty good and within a few points and almost 128. This is not the issue. Fuel pressure checks out at WOT as good 43-45 PSI.

I am running VE and am calibrating the tables at WOT (have been for many years) by disabling PE. First run indicates the fueling crosses over to lean at about 4300 RPM and stay lean until 6600 RPM where my BPW is 12.9 ms and the Short term counts are reading 155 (very lean). Long terms are 129 and 128 so they have not moved yet. 02's confirm a lean condition with reading of about 50 mV.

OK, now I reprogram and gradually add up to 20% up top to the VE tables to see if this helps. Here is where the strange thing happens. On the second run, the car again goes lean at 4300 RPM and at exactly 6600 RPM, the injectors are reading 16.2 (25% increased in flow) but the ST counts are again at 155 with BLMS at 129 and 128! Yes this is confirmed by the car hesitating up top as it runs out of fuel.

The only thing I can think is these Venom injectors are not doing what they are supposed to do. I have heard stories on other boards of them causing cars to go lean and people damaging engines.

what do you all think?

I should not be running out of fuel on my setup at 4300 RPM however, I am not sure at 6600 RPM. I can only estimate RWHP but think that I am north of 450.

 

What specific issue were you encountering that made you decide to disable PE and run VE full time? With the limited number of BLM cells and the narrow operating ranges they are defined for, I would not want to trust the long term fuel trims to take me safely to 6600 RPM, especially with a radical cam. BLMs have their specific operating purposes, which is part throttle low RPM cruising to optimize emissions, and so does PE, which is for power and engine safety.

I would stop running to 6600 RPM until you can fix the problem at 4300. Narrow band O2s aren't that accurate but 50 mV is dangerous at WOT. I would begin by checking fuel pressure, and if pressure is good test re-enabling PE and see what happens.

 

Thanks for the reply.

I had no "issues" in disabling PE. That is the way I calibrate the VE tables. I know that narrow bands are not accurate and when I spoke of "going lean" it meant to indicate the crossover point (450 mV) has been reached and I am now lean.

My FP checked out fine at WOT.

I have reenabled PE and it still goes lean up top, if only 3-400 RPM higher.