Does anyone know if you can put both the Walbro 390 and the new Airtex vane pump in line. i would assume so because they are both vane type pumps.
The Walbro is set up with a TPS sensing device that is supposed to keep the pressure at 10psi and increase as rpms and demands increase. I continue to have problems with the pressure fluctuating.
Any suggestions?

 

I would pull the Airtex, install the Walbro in it's place, note the results - if Walbro does similar, maybe the fuel line from the tank is blocked - otherwise, if the Airtex is 10psi, the output from the stacked Walbro will be 20psi - also possible if Airtex doesn't have sufficient flowrate by itself, it could restrict flowrate of Walbro - best to try the Walbro by itself