Fuel Pump Upgrade
John Runnion
Introduction
The procedure described here was described by former GN/T-Type list member John Runnion in March and April of 1993. This was intended to be a low-cost in-tank fuel pump upgrade.

The pump that was used is a Masters fuel pump (part number is E3270) for Syclones, Typhoons, and '92 S-10 trucks with the 4.3L CPI engine. You can reach Masters at (618) 842-2111 to see which dealers in your area carry the pump. However, any brand pump made for this application should produce the same results.

The Masters catalog also lists all the GPH ratings for their pumps.

. GPH@WOT PSI Cut-Off
Stock Turbo V6 40 60
Syclone 50-60 80-90

Installation Notes
The problem is that the Syclone pump is 0.45 inches shorter than the stock pump and has a slightly different bottom gasket. You must fashion an "extender" to make sure the pulsator seats properly. It will not work without an extender.

The extender is a 0.7" length of 5/16" O.D. stainless fuel line, chamfered and smoothed on the pulsator (bottom) end and smoothed on the fuel line (top) end.

The extender will be sleeved onto the fuel line (above the pulsator) with about 2" of 5/16" flexible fuel line and then clamped down. About 0.4-0.5" of the extender will actually protrude from the sleeve and seat into the pulsator.
Procedure
1. Cut the stock bottom gasket to fit the Syclone pipe. Basically, you need to remove about "30 degrees" of the nose of the gasket.
2. The extender/pulsator fit will be tight, to make sure of a good seal. When actually installing it, you have to seat the extender into the pulsator first (chamfered side in--you don't want to cut up the rubber seat in the pulsator).
3. Next, fit the flexible tube sleeve onto the fuel line tube up all the way. Next, discard the rubber seat around the fuel pump outlet pipe, and fit the pulsator onto the fuel pump outlet pipe as far down as it'll go.
4. The extender should now be firmly seated between the pulsator and the fuel line tube. Finally, shift the sleeve down onto the extender as far down as possible and tighten with a hose clamp.


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