The past couple of weeks I have been learning more about tuning with a chip. I'm using the $0D v175.xdf and my ecu is BJLH. Right now I am working on the vehicle in my sig - and was curious what the O2 Sensor MV should range from?

When i datalog i get weird spikes throughout the entire log - but when im at 2650rpms, my o2 mv is 70.80, BLM is 157, according to tunerpro. I am always wondering if anyone could point me to a guide on adjusting the fuel parameters in this definition file (or is it as easy as adjusting fuel pressure) - BLMs show its lean.

 

My o2 mv are swinging around a lot too, and the BLMs range from about 114-145. I'm putting my wideband on it this weekend hopefully to start getting it sorted out. I dont know that I trust what it's telling me...the truck seems to drive worse in closed loop than open.

But to answer your question:

The way to add fuel is to increase the VE table in the cells where you are lean. This is done by RPM and MAP. In my def it is under the BPW heading in the VE vs RPM vs MAP table.

You should make sure the actual flow your injectors are putting out at your pressure match the injector flow constant in the bin first though.

 

Thanks Woody. I did notice that my BLM is at 128 at idle, but as soon as I open her up she spikes to 135+ instantly. I can go light on the gas and it still spikes. I also have a Innovation LC1 wideband which I want to put in for testing.

I think I am going to pick up new injectors which are flow tested - I am not sure how to tell how much these are flowing without sending them out, getting them tested and with winter and snow here, need the truck since my car is parked for the season.

 

Are you still at stock fuel pressure? You can convert your stock FPR to be adjustable and up the pressure for more lb/hr for free.

 

Yes - still at stock pressure (i am assuming 12psi, but no idea how old the pump is).

I just ordered a fuel pressure gauge (0-30psi) and an adjustable regulator. Should be here next week sometime.

 

Don't be surprised if you can't get much more out of the stock pump. I tried it since I read the stock pump could go to 16-18psi...but I could only get 11psi with the regulator wide open. So I bought an EP241 TPI pump from Rockauto for like $70 and it drops right in. Even then I could only get 14psi with the stock regulator spring and had to order a heavier one. So when you modify your regulator I'd drop in a new heavier spring at the same time and save yourself from taking it apart again.

 

I ordered an external fuel pressure regulator, and also ordered a block off plate for the stock one. The external one I ordered is good for 0-100psi, so I'm assuming it will work for my purpose.

It looks like I may be ordering a new fuel pump, I have no idea how old this one is. I recently replaced the sending unit, and now I regret not changing the pump at the same time Everyone told me I would regret it - now I do lol.

 

Here is an update - Been messing with the tables a bit and seems like it has no effect on the BLMs. So I think my fuel pressure may be off (electric pressure gauge should be here tomorrow so I know for sure). I did notice that it runs really nice in open loop vs closed loop. So I adjusted the bin file to always be in open loop instead of going to closed loop. It runs a ton better, O2 sensor mV are not as jumpy according to Tunerpro, altho according to tunerpro my BLM are a steady 128 in open loop, and they do not move.

I am thinking the closed loop could possibly be related to an O2 sensor issue? I have no idea how old my o2 sensor is.

Woody, just curious if you managed to get your wideband hooked up and noticed anything between your open/closed loop running?

 

I've confirmed it definitely runs much better open loop than closed, but haven't got the wideband on it yet. I did finish my first tank of gas for an impressive 6.7mpg...haha

 

ouch - that mileage would kill my bank account hehe.

For some reason my truck appears to run much better in open loop as well - the o2 sensor voltage doesn't bounce around dramatically like it does in closed loop. I think it may be a bad o2 sensor, but I am not 100% sure yet. In closed loop my idle has a little studder to it, but in open loop there is no studder.

I did edit the fuel tables in my bin file to richen it up a little, the highest BLM I saw now is about 130, compared to 158 like it was - my fuel pressure gauge comes in today, so I will be hooking that up later tonight to see my fuel pressure.