*UPDATE: Hooked up fuel pressure gauge* Runing lean at top of RPM before shifting
03-12-2018, 11:00 AM
#1
*UPDATE: Hooked up fuel pressure gauge* Runing lean at top of RPM before shifting have not been able to setup my new laptop yet with hp tuners (old laptop crapped out on me). currently scanning via the torque pro app. the issue is that when I go WOT, the wideband will go lean gradually to like 13.xx and sometimes 14.x at top of the gear (2nd gear) and once it shifts to 3rd, the AFR goes back to normal around 12.x before I let off around 110mph. I had only done this 2-3 times so hopefully my motor's not busted 
. btw no knock retard occurred when I did the pulls.
currently running a used walbro 255lph fuel pump with ~15-20k miles (bought it from a member on here when it had 10k miles). no rewire (have one on the way). gtp injectors and fuel filter prolly has about 20-25k miles on it. I just replaced the wideband sensor to see if it was the sensor crapping out but was not the issue.
could a worn out alternator (original 151k miles) be a possibility because if the car would sit in the garage 7-14 days w/o driving it'll need a jumpstart (currently have a battery tender jr. to charge it on days of not driving the car).
could it be the fuel pump? I ask because my firebird did a similar issue on the stock fuel pump and once I swapped it out with a racetronix fuel pump it fixed the issue.
. btw no knock retard occurred when I did the pulls. currently running a used walbro 255lph fuel pump with ~15-20k miles (bought it from a member on here when it had 10k miles). no rewire (have one on the way). gtp injectors and fuel filter prolly has about 20-25k miles on it. I just replaced the wideband sensor to see if it was the sensor crapping out but was not the issue.
could a worn out alternator (original 151k miles) be a possibility because if the car would sit in the garage 7-14 days w/o driving it'll need a jumpstart (currently have a battery tender jr. to charge it on days of not driving the car).
could it be the fuel pump? I ask because my firebird did a similar issue on the stock fuel pump and once I swapped it out with a racetronix fuel pump it fixed the issue.
Last edited by fst100; 04-23-2018 at 07:02 PM.
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03-12-2018, 01:44 PM
#10
the AFR/tune was fine prior to the issue. the only major change I can think of is that I was getting a P0101 which was a variance that the MAF table was higher than what was in my VE table. once I adjusted the VE table, the P0101 was gone. do you think that may have something to do with this lean condition?
after the new maf I had to retune it again but was still getting the lean up top of the RPM.
checking the battery voltage is something I'm thinking as well. battery's fairly new but the alternator hasn't been changed since I owned it. I can uninstall it and take it to advance auto parts and have them test it if its able to maintain charging. thoughts?
after the new maf I had to retune it again but was still getting the lean up top of the RPM.
checking the battery voltage is something I'm thinking as well. battery's fairly new but the alternator hasn't been changed since I owned it. I can uninstall it and take it to advance auto parts and have them test it if its able to maintain charging. thoughts?
03-12-2018, 01:49 PM
#11
You said you're running OLMAF, so VE shouldn't care at all. Just a heads up though, you cannot just swap MAF's and expect to see the same results. The heater element inside the MAF's are not all identical and can screw AFR, especially at higher power levels.
1st thing I'd do is log battery voltage and look at fuel pressure and go from there.
1st thing I'd do is log battery voltage and look at fuel pressure and go from there.
03-12-2018, 01:57 PM
#14
I'm an EFI Live guy, so for me its in engine calibration>Fuel>Airflow> then B0120 RPM Threshold for airflow calculation. Basically this table tells it to look at the MAF exclusively for any RPM about what you enter into the cell. Below this RPM it will use the VE/MAF hybrid.
