Jumper to avoid being stranded with a failed Primary Fuel Pump

[Dynomite]

Originally Posted by WVZR-1

I would think you would want sufficient length between connectors to maybe pass the four wires through a "heat-shrink" tube when constructing and then shrinking to keep the bundle secure. Wouldn't need to be long but I believe needs to have some length to avoid struggling when connecting.

I'd think Jim has first-hand knowledge of a practical length and I'd certainly inquire/enlist his help before constructing.

Cliff - did you check the "clocking" of the black and green/white on yours?

Good suggestions and what I was thinking also in terms of installation without having too long a jumper to try and stuff back into position under the rubber boot

I am going with what Jim described as follows.......and I am assuming 90's and 91's are identical.

Originally Posted by QB93Z

A - Black - DC Ground
B - Purple - Fuel gauge signal
C - Gray - Fuel Pump
D - Green/white - Fuel Pump
Jim

Black is Black,
Purple I call Red,
Gray I call White,
Green/white I call Green.

Originally Posted by QB93Z

Background: If number 1 fuel pump fails, the LT5 will start properly but then die after a short period of time. When the engine is cold, the period may be almost a minute. When the engine is at operating temperature the engine will die immediately after starting.

This happens because the ECM energizes BOTH fuel pumps on engine start. So the Secondary Fuel Pump supplies fuel to the injectors while the primary pump does nothing. Once the engine is operating properly, the ECM turns off the Secondary Fuel Pump and the car stalls.

Why does the ECM have to energize BOTH fuel pumps on starting?

Originally Posted by GOLDCYLON

Ok any others out there ?

Four Jumpers for Dynomite.......