View Single Post
Grady Clay Grady Clay is offline
Registered User
Grady Clay's Avatar
Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
Posts: 9,032
John has some good ideas here.

Nein14-6, is the electric fuel pump seal being pushed out, pulled in, or failing in some other way? What did you do with the failed pumps? I’m sure the manufacturers would like them back and tell you how they failed. Record all the numbers on the part and engrave your name. Get them perfectly clean from any fuel and send them via Certified US Mail. Almost all manufacturers want to analyze failures, not suffer lawsuits.
From your diagram it looks like the stock fuel console/filter is not in place, is that true?

Souk, yes, the mechanical pump voodoos the fuel (via steel or plastic pipes) to the injection nozzles in the intake just prior to the valve. That is the art of MFI.

You need to find the source of this problem before you make any other changes. The pumps you are using are good equipment and shouldn’t fail in this manner.
My suggestion of the day is to remove the filter prior to the pump as it duplicates the screen in your black box. Please inspect/clean the screen in the tank.
I recommend a real filter just after the electric pump. I use a Bosch 0.450.905.016 from ’74-> CIS. I made silver soldered adaptors to -6 line. Perhaps positioning your fuel pressure gauges between the electric pump and the (new) filter and just prior to the pressure regulator might yield the most information. You could extend the gauges (carefully with -2 SS Teflon hose) so you can see them while driving, Be extremely careful with pressurized (or any) fuel in the cockpit!

You said you plan to go to carburetors. That is OK if cost is the issue. MFI gives more performance and better throttle response. See the threads on MFI.

ANSWER PRICE LIST (as seen in someone's shop)
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50
Old 01-28-2004, 09:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)