1 87 k100 RT, intermittent fuel pump operation. SOLVED! Fri Apr 24, 2015 1:58 pm
fourwinds
active member
Fuel pump can be heard running with ignition key on, before pressing starter button.
Starts & runs for a few seconds, then engine dies. Fuel pump clearly RE-starts after engine dies.
This leads me to suspect that it is shutting off at some point & thereby causing engine to stop.
Following the excellent diagnostics & info shared here ;
Have tested the connector to the FI controller. Air flow meter tests OK via FI connector.
FI relay socket shows to be operating correctly. Tested FI relay on bench, "clicks" when you put power to it. 4-wire connector to tank tests OK.
Tested for power at #6 fuse socket: Zero volts left side, zero volts with starter button pressed.
12v at Right side, drops rapidly to zero when starter button is pressed.
As a test, I put her all back together, jump a wire from positive terminal of battery to the left side of the #6 fuse, and she'll run all day.
The puzzle is this: what is causing the fuel pump to stop running during the starter engagement cycle?
Starts & runs for a few seconds, then engine dies. Fuel pump clearly RE-starts after engine dies.
This leads me to suspect that it is shutting off at some point & thereby causing engine to stop.
Following the excellent diagnostics & info shared here ;
Have tested the connector to the FI controller. Air flow meter tests OK via FI connector.
FI relay socket shows to be operating correctly. Tested FI relay on bench, "clicks" when you put power to it. 4-wire connector to tank tests OK.
Tested for power at #6 fuse socket: Zero volts left side, zero volts with starter button pressed.
12v at Right side, drops rapidly to zero when starter button is pressed.
As a test, I put her all back together, jump a wire from positive terminal of battery to the left side of the #6 fuse, and she'll run all day.
The puzzle is this: what is causing the fuel pump to stop running during the starter engagement cycle?
Last edited by fourwinds on Sat Apr 25, 2015 1:29 am; edited 1 time in total (Reason for editing : solved problem)