Z31 Fuel Pump Replacement(Upgrade)

Fuel Pump Replacement(Upgrade)

When Upgrading your Z31 Fuel system You will need to factor in a few important items in the Modification. First thing is the ECU and Injectors you are using. The 84-89 ECCS is virtually limitless in its potential, the devices attached to it are not. The stock fuel injectors on a 84-89 Z31 Turbo have a flow rate of about 260CC/min. This means at maximum duty cycle and stock (37psi) fuel pressure they will actually put out less than 260cc's of fuel in one minute. However the stock ECU limits the injectors duty cycle to around .80 or 80% duty cycle. In addition, injectors are rated at maximum flow (with the pintle fully open) meaning they never reach this level of flow in operation. This means on an entirely stock fuel system (and stock engine) you will have AT MOST ~300HP at the crank (and probably running lean up top), and at that point you will also be maxing out the stock T3 turbocharger as well. You can read More Information about Fuel Injectors at SDS's Website

So with all this said, You will need to upgrade your fuel pump before going much further. The stock Z31 fuel pump (same for NA and Turbo applications) will have trouble keeping up fuel flow at anything over 300 crank HP. You can Use a Stock Z32 TT unit or Walbro GSS342 255lph Pump and supply ample fuel for 500HP.

Below you will see the process of Removing and upgrading your Fuel Pump in the Z31.

Tools Needed

  • Phillips Screw Driver
  • Flat head Screw Driver
  • 10mm socket
  • 12mm socket
  • 14mm socket
  • Ratchet
  • Pliers
  • Jack
  • A friend

Fuel Pump Part Numbers that work

  • Walbro GSS342 - 255lph
  • DeatschWerks DW300 - 320lph

Video Of the Process

Provided By: Turbocharged Creations

Sources Used on This Page:

Writen by: Jason Butts (redz31)

Video By: Turbocharged Creations