Going LEAN! Need help!

[0-60B4U]

I recently upgraded from Steggy Stage 5 w/ported TB &Plenum, Diablo Mafia w/factory MAF, 63lb injectors and C&L intake to a 2.3L Whipple, Accufab SBTB, JLT High boost, SCT BA2600, KB BAP w/wiring upgrade and new LUND tune. The car idles great but when you give the car very much throttle it instantly goes lean. I've checked the pumps and they are good and even datalogged the car before and after the BAP install to see if the BAP was working and it is. I can't seem to figure out why it's going lean. Any suggestions and insight would be greatly appreciated. I can even email my datalogs to you if that will help.
Thanks in advance! :beer:

 

[Cobra03SC]

It may be a good thing to hook up a Fuel pressure gauge to see if it drops when you give it throttle. Maybe check the fuel filter also, something obviously isnt flowing like it should.

 

[0-60B4U]

It may be a good thing to hook up a Fuel pressure gauge to see if it drops when you give it throttle. Maybe check the fuel filter also, something obviously isnt flowing like it should.

I have a fuel pressure guage and the pressure guage shows that it's raising when I give it throttle but in the datalog it looks like its fighting to stay around 40psi (38-44psi). I just changed the fuel filter about 5-6mths ago and have only put 500 miles or so on the car since but I will check that. I recently replaced the FRPS and installed KB Fuel Rail Pressure Disc because I popped the first one after the BAP install. Would that have anything to do with it? I'm grasping at straws trying to figure it out. It's like the car doesn't see boost or throttle? :??:

 

[JRS03]

Are you saying that when you blimp the throttle at idle it goes lean on the gauge? If so, I believe it's normal because you are not under load. Are u on a email tune or actual dyno tune? Fuel pressure should be around 32 at idle and 38-40 on the throttle. Need a little more info

 

[Cobra03SC]

If you drive it and at idle sits around 15, and at WOT its under 12, then it sounds pretty normal. Its going to show lean like he said because the car isn't under load. Revving it wont really tell you anything.

 

[Anabolic]

mine idles 14.2-15.2 If i give it gas to just rev alittle & pulse it once it goes to max 22.4 & then back to normal.

 

[01Jes]

Datalog your FPDC and fuel pressure

 

[0-60B4U]

Are you saying that when you blimp the throttle at idle it goes lean on the gauge? If so, I believe it's normal because you are not under load. Are u on a email tune or actual dyno tune? Fuel pressure should be around 32 at idle and 38-40 on the throttle. Need a little more info

Everything runs fine at idle and A/F stays around 14.4-15.2. When I rev at idle it gets a little richer. When I'm driving at cruise speed (2200-2500rpm) everything is great but when you start to accelerate very hard the car goes lean instantly (16.0 A/F). It's like the car isn't sensing the boost or the added air. I've cleaned the MAF (even though I just bought it). Could it be a bad MAF?

 

[0-60B4U]

If you drive it and at idle sits around 15, and at WOT its under 12, then it sounds pretty normal. Its going to show lean like he said because the car isn't under load. Revving it wont really tell you anything.

Idle is great (14.4-15.2 A/F) and at cruising speed its great. It's when you accelerate hard or go WOT it jumps instantly lean (16.0 A/F).

 

[0-60B4U]

Datalog your FPDC and fuel pressure

I datalogged both with after I installed the BAP. The FPDC never gets above 0.20 and fuel pressure never gets above 44psi. I would think with my BAP, 63lb injectors the fuel pressure would get higher at WOT?

 

[01Jes]

Everything runs fine at idle and A/F stays around 14.4-15.2. When I rev at idle it gets a little richer. When I'm driving at cruise speed (2200-2500rpm) everything is great but when you start to accelerate very hard the car goes lean instantly (16.0 A/F). It's like the car isn't sensing the boost or the added air. I've cleaned the MAF (even though I just bought it). Could it be a bad MAF?

Can you load an old tune to see if the problem stays the same? Sounds like the problem is in the revised tune.

 

[0-60B4U]

Can you load an old tune to see if the problem stays the same? Sounds like the problem is in the revised tune.

I did install the old tune and it does the same thing but I'm not sure thats a good comparison since I upgraded to SBTB, SCT BA2600, JLT High boost which I didn't have previously.

 

[Anabolic]

check plug gap & everything. mine's breaking up & plugs had some oil around the COP, VC gasket is leaking. but AFR pegs to 19 when i blip the throttle & it starts missing alittle

 

[0-60B4U]

check plug gap & everything. mine's breaking up & plugs had some oil around the COP, VC gasket is leaking. but AFR pegs to 19 when i blip the throttle & it starts missing alittle

I just replaced the plugs with NGK BR7EF gapped to 0.30. After I drove the car I pulled the plugs and they were white on the ends. Do you think it could be the MAF? It's not throwing any codes so that may not be it.

 

[Anabolic]

how white? alittle tinge is ok/normal

NGK Spark Plugs USA

http://www.gnttype.org/techarea/engine/plugs.html

 

[c6zhombre]

How did you verify the bap is working? Best way is get a voltage meter and make sure. Also, there's a pid called pressure drop across injectors, log that one and send a log file back to your tuner after you verify all hardware is functioning....doesn't sound like it to me. Major fuel delivery issue going on

 

[0-60B4U]

how white? alittle tinge is ok/normal

NGK Spark Plugs USA

Spark Plug Analysis

The plugs looked like they had a little dried milk on the very end of them. Looked like normal according to the link you sent. Thanks!

 

[0-60B4U]

How did you verify the bap is working? Best way is get a voltage meter and make sure. Also, there's a pid called pressure drop across injectors, log that one and send a log file back to your tuner after you verify all hardware is functioning....doesn't sound like it to me. Major fuel delivery issue going on

I verified the BAP was working by datalogging the FPDC with the BAP on then took it off and datalogged it again. With BAP installed FPDC was 0.10 at 2490rpm and without it the FPDC was 0.33 at 2416rpm so it seemed like it was working. Plus, on my A/F guage you could watch it change when you turned the BAP dial.

 

[cj428mach]

I assume its in your tune. When you're tipping the throttle open you'removing in a lot more air now thanks to the bigger blower and the sbtb.

 

[Anabolic]

how about you take your wideband O2 sensor out & free air calibrate it again, suggested every oil change or so. 20k+ miles on you're likely needing a new sensor. makes no sense it would just randomly run lean if you didn't do anything to it. EDIT: AND switched the tunes back