88 Intermittant FP Relay Circuit Prob
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
88 Intermittant FP Relay Circuit Prob
greetings all,
unusual problem here and i am w/o my helms until wednesday, ugh! went to start car yesterday and it would not start. vats bypassed, new relay for fp, no bad fuses. i actually cranked the battery low. i had noticed that the fp relay was not engaging because when i put my finger on it and turned the key, i felt/heard nothing. i had spark but, no fuel delivery.
ok, so i drag out my 200 amp starter/charger and apply the clips/cables. then i turned the key, could feel and hear the relay "click in", and the car had fuel and started. this happened to me in the recent past and thusly, i replaced the fp relay.
this situation has happened to me before only after the car would sit for 3-5 days w/o being driven (that's why i changed the relay). what i believe is that there is a bad connection in this circuit somewhere and the the extra current supplied by the starter/charger is "making the connection" when the key is turned.
the pins going into the relay are clean and shiny and plug appears to have no burned/frayed/or broken wires. i an thinking that could there be a crappy connection at the fuse panel where the fuse slides in?...if not, where should i look until i can retrieve my helms?.......thanks again...
unusual problem here and i am w/o my helms until wednesday, ugh! went to start car yesterday and it would not start. vats bypassed, new relay for fp, no bad fuses. i actually cranked the battery low. i had noticed that the fp relay was not engaging because when i put my finger on it and turned the key, i felt/heard nothing. i had spark but, no fuel delivery.
ok, so i drag out my 200 amp starter/charger and apply the clips/cables. then i turned the key, could feel and hear the relay "click in", and the car had fuel and started. this happened to me in the recent past and thusly, i replaced the fp relay.
this situation has happened to me before only after the car would sit for 3-5 days w/o being driven (that's why i changed the relay). what i believe is that there is a bad connection in this circuit somewhere and the the extra current supplied by the starter/charger is "making the connection" when the key is turned.
the pins going into the relay are clean and shiny and plug appears to have no burned/frayed/or broken wires. i an thinking that could there be a crappy connection at the fuse panel where the fuse slides in?...if not, where should i look until i can retrieve my helms?.......thanks again...
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Try looking at the fusible links behind the battery. The FP relay and oil pressure switch power branches from there. If the relay were bad the oil pressure switch should start the car (if no other variables like short/grounded fuel pump circuit) after the oil pressure reaches 4 psi.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by RRT vette
Try looking at the fusible links behind the battery. The FP relay and oil pressure switch power branches from there. If the relay were bad the oil pressure switch should start the car (if no other variables like short/grounded fuel pump circuit) after the oil pressure reaches 4 psi.
i forgot about the oil pressure switch being in the same circuit to the fp relay however, that would not explain the intermittent no power to the fp relay as i had +4lbs pressure. if there was no oil pressure (4lbs) the car would not start or would die if the engine was running as a safety precaution, correct?
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Here is a link to an explanation by CFI-EFI about the interaction
of components on the fuel pump circuit for an '89. As mentioned
earlier in this thread, the '89 hardware differs from the '88 in that
discrete devices are used for OP gauge pressure sensing/fuel pump
switching in '88.
Combined Oil Pressure Sensor/Switch for '89 ?
.
of components on the fuel pump circuit for an '89. As mentioned
earlier in this thread, the '89 hardware differs from the '88 in that
discrete devices are used for OP gauge pressure sensing/fuel pump
switching in '88.
Combined Oil Pressure Sensor/Switch for '89 ?
.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by Slalom4me
Here is a link to an explanation by CFI-EFI about the interaction
of components on the fuel pump circuit for an '89. As mentioned
earlier in this thread, the '89 hardware differs from the '88 in that
discrete devices are used for OP gauge pressure sensing/fuel pump
switching in '88.
Combined Oil Pressure Sensor/Switch for '89 ?
.
of components on the fuel pump circuit for an '89. As mentioned
earlier in this thread, the '89 hardware differs from the '88 in that
discrete devices are used for OP gauge pressure sensing/fuel pump
switching in '88.
Combined Oil Pressure Sensor/Switch for '89 ?
.
