I have made a discovery today after the installation of my Aeromotive AFPR. Im running a standalone with no closed loop correction. It Runs directly off the same programed fuel map at all times.
I installed my Aeromotive AFPR and set it to 40psi with no vacuum. I set it this way as the service manual says 33-40PSI is stock spec. My car was running on the stock regulator so i wanted to get it running then adjust the fuel pressure to make the mixture correct so i would need to make minimal changes to the fuel map.
Upon turning the key the car was very hard to start. I got the car running kept the RPM up at about 1200 so it would stay running and i booted up the computer. I opened the Zeitronix program to find my AFR's in the 17.5-18:1 range. I felt that was slightly odd as i was just driving the car prior to installing the AFPR.
I increased the fuel pressure until the AFR's got into a reasonable range that the car would run on its own.
This is the Surprising part. I had to increase fuel pressure to 55PSI WITH VACUUM. This means without the approx 9.5psi of vac to the regulator, base fuel pressure would be 64.5PSI!
At first i figured maybe my stock regulator was a freak and was actually regulating fuel pressure to that level. I took the car around the block and at 5 psi where my AFR's are usually in the 13-12.5 range instantly dropped to the low 10's. At 10psi i was in the 9's.
Before anyone asks i have removed the J-Tube and the only things that changed were the regulator itself. The rubber hose that slips onto the hard line off the outlet of the stock regulator is slid onto a hose barb at the outlet on the bottom of the Aeromotive unit.
To all who run a Walbro fuel pump i would HIGHLY recommend changing out the stock regulator for a higher flowing unit. The stock regulator even with the J-Tube bypassed was restricting flow so much as to raise the fuel pressure 25+PSI untill the motor was consuming enough fuel to let the regulator operate as designed.
Running a Walbro should either be complimented with a higher flowing regulator, or keep the stock fuel pump resistor circuit in functioning order to lower the flow at low engine load.
I installed my Aeromotive AFPR and set it to 40psi with no vacuum. I set it this way as the service manual says 33-40PSI is stock spec. My car was running on the stock regulator so i wanted to get it running then adjust the fuel pressure to make the mixture correct so i would need to make minimal changes to the fuel map.
Upon turning the key the car was very hard to start. I got the car running kept the RPM up at about 1200 so it would stay running and i booted up the computer. I opened the Zeitronix program to find my AFR's in the 17.5-18:1 range. I felt that was slightly odd as i was just driving the car prior to installing the AFPR.
I increased the fuel pressure until the AFR's got into a reasonable range that the car would run on its own.
This is the Surprising part. I had to increase fuel pressure to 55PSI WITH VACUUM. This means without the approx 9.5psi of vac to the regulator, base fuel pressure would be 64.5PSI!
At first i figured maybe my stock regulator was a freak and was actually regulating fuel pressure to that level. I took the car around the block and at 5 psi where my AFR's are usually in the 13-12.5 range instantly dropped to the low 10's. At 10psi i was in the 9's.
Before anyone asks i have removed the J-Tube and the only things that changed were the regulator itself. The rubber hose that slips onto the hard line off the outlet of the stock regulator is slid onto a hose barb at the outlet on the bottom of the Aeromotive unit.
To all who run a Walbro fuel pump i would HIGHLY recommend changing out the stock regulator for a higher flowing unit. The stock regulator even with the J-Tube bypassed was restricting flow so much as to raise the fuel pressure 25+PSI untill the motor was consuming enough fuel to let the regulator operate as designed.
Running a Walbro should either be complimented with a higher flowing regulator, or keep the stock fuel pump resistor circuit in functioning order to lower the flow at low engine load.