fuel pump relays
Discussion
after a brief flirt with a 911 im back in the fold with my third tvr. this time a splendid starmist blue griff 500.
collected it friday, had sp12s fitted saturday, wont start on sunday ! this is the life... i missed this.
ok .. heres the thing.
key fob unlocks door, key in ingnition, lights on dash, 12v on meter, press the button and....no pump whirr.
i switched the relays over and it worked once, then never since. i bought one relay (they only had one), admittedly not a bosch one, and nothing. i can hear them clicking and occasionally they whirr when i remove the key from the ignition but otherwise....dead.
if i try to start the car it will crank ok but wont fire.
im guessing fuel pump or relays. any thoughts, do i need the bosch ones?, why do they click and whirr if they aint working and how do they stop working ?.. is it poor contact or dry joints or what ?
finally.. i still have a beautiful silver 911 for sale, it always starts and never answers back.. am i nuts ?
collected it friday, had sp12s fitted saturday, wont start on sunday ! this is the life... i missed this.
ok .. heres the thing.
key fob unlocks door, key in ingnition, lights on dash, 12v on meter, press the button and....no pump whirr.
i switched the relays over and it worked once, then never since. i bought one relay (they only had one), admittedly not a bosch one, and nothing. i can hear them clicking and occasionally they whirr when i remove the key from the ignition but otherwise....dead.
if i try to start the car it will crank ok but wont fire.
im guessing fuel pump or relays. any thoughts, do i need the bosch ones?, why do they click and whirr if they aint working and how do they stop working ?.. is it poor contact or dry joints or what ?
finally.. i still have a beautiful silver 911 for sale, it always starts and never answers back.. am i nuts ?
Not much help but the whirring when the key removed might be the stepper retracting and not the relays themselves,interesting the fact that swapping the relays worked the once,checked the relay bases to see if the crimps have been pushed out of their sockets and now not making contact ? other option to test the pump and see if there is voltage there when the ignition is turned on and it should get a feed from the ecu to prime the system,if there is then the pump is suspect,if not then need to trace at the relays to see whats happening.
ETA sorry but this is funny and glad you can see it too
ETA sorry but this is funny and glad you can see it too
bananaface said:
collected it friday, had sp12s fitted saturday, wont start on sunday ! this is the life... i missed this.
Edited by rigga on Sunday 12th June 15:28
I had a relay pack up, then replaced both (non bosch) .... to be on the safe side, then, hit a largish pot hole and stopped, car wouldn't start. AA recovery into my own garage then loads of testing & tinkering but nothing. Was about to get car taken to auto electrician when one final chech with ignition on meant I had to move the wiring loom in drivers footwell and ..... fuel pump burst into life. I spent some time tracing the offending contact, pushed the relay home hard and no further trouble.
... 
The standard Bosch relays used with the red stripe (part No 0732014112) have an ECU protection diode in series with the coil.
Relays with diode protection are widely available, but they normally have the diode in parallel with the coil (across from 86 to 85) and I’m afraid I don’t know if this type of relay provides adequate protection for the ECU.
So be careful what you buy and check any claims that they are an alternative replacement part, the relays often have the circuit diagram on the case. I have bought these in the past from so called specialists and they have not been correct.
Cheers,
Simon.
Relays with diode protection are widely available, but they normally have the diode in parallel with the coil (across from 86 to 85) and I’m afraid I don’t know if this type of relay provides adequate protection for the ECU.
So be careful what you buy and check any claims that they are an alternative replacement part, the relays often have the circuit diagram on the case. I have bought these in the past from so called specialists and they have not been correct.
Cheers,
Simon.
ok .. the current state of play.
my relay, the one i bought, flattened the battery overnight, no switched live i guess.
word to the wise, only get the bosch one.
the car is now sitting on those sp12 wheels looking gorgeous, outside the house with a flat battery and a two new bosch relays, and i think a duff fuel pump... many thanks to kerridges for trying last night with a booster pack but to no avail, the new relays click and the pump does nought...we crank and we dont fire.
i should just about have this running in time for the rain forecast this weekend when i can go out in my new torquey car with its new unscrubbed tyres and loose it on the nicely greasy roads...
sigh...
my relay, the one i bought, flattened the battery overnight, no switched live i guess.
word to the wise, only get the bosch one.
the car is now sitting on those sp12 wheels looking gorgeous, outside the house with a flat battery and a two new bosch relays, and i think a duff fuel pump... many thanks to kerridges for trying last night with a booster pack but to no avail, the new relays click and the pump does nought...we crank and we dont fire.
i should just about have this running in time for the rain forecast this weekend when i can go out in my new torquey car with its new unscrubbed tyres and loose it on the nicely greasy roads...
sigh...
There is an equivalent from Euro car parts that is better made(yes with the diode in the correct place too)I have fitted 2 pairs with no problems whatsoever in fact I have retained my 2 for my Megasquirt install and these are over 3 years old 
earlier BMW's share this type of relay too 
the only benefit of the Bosch is you can open up the case and knock the carbon of the contacts as a temp repair 
earlier BMW's share this type of relay too the only benefit of the Bosch is you can open up the case and knock the carbon of the contacts as a temp repair ok well turns out it was the immobiliser, new one being fitted tuesday. apparantly the car can crank still when the immobiliser isnt working.
however.. i still have the other issue, stalling.
the old pull to a junction or lights and hic splutter stall...
idle has been reset, new leads and plugs, no missing or other tells, just the occasional idle stall.
any ideas ?
however.. i still have the other issue, stalling.
the old pull to a junction or lights and hic splutter stall...
idle has been reset, new leads and plugs, no missing or other tells, just the occasional idle stall.
any ideas ?
over that din are you sure? 
ok she is back and sounding all good n beasty. this has given me the opportunity to feel out the stall.
on idle, and under electrical load i think is the cause, problem happens most when in stop start traffic and the fans cut in and out lots the as the surge hits the alternator (im guessing) and the revs dip so the car can start to struggle and hunt erratically. tbh it sounds awesome in an eleanor 60 seconds kinda way with the sleeved zorsts, but nonetheless it can be a pain in the ass heel toeing and such to keep her awake.
any ideas ?
on idle, and under electrical load i think is the cause, problem happens most when in stop start traffic and the fans cut in and out lots the as the surge hits the alternator (im guessing) and the revs dip so the car can start to struggle and hunt erratically. tbh it sounds awesome in an eleanor 60 seconds kinda way with the sleeved zorsts, but nonetheless it can be a pain in the ass heel toeing and such to keep her awake.
any ideas ?
I fitted a fan override switch, so on hot days when stopped in traffic I just switch the fans on constantly helps keep thing cool and it stops the surging.
Many ways to do this, but the Simple way is to wire a short on the otter switch at the bottom of the swirl tank, run this to a hidden switch below the dash somewhere. Don’t forget to fuse it, just in case.
Cheers,
Simon.
Many ways to do this, but the Simple way is to wire a short on the otter switch at the bottom of the swirl tank, run this to a hidden switch below the dash somewhere. Don’t forget to fuse it, just in case.
Cheers,
Simon.
diodes are plced across coil to supress the induction effect caused when the coil is switched off and thus protects the switch contacts
Simon.b said:
The standard Bosch relays used with the red stripe (part No 0732014112) have an ECU protection diode in series with the coil.
Relays with diode protection are widely available, but they normally have the diode in parallel with the coil (across from 86 to 85) and I’m afraid I don’t know if this type of relay provides adequate protection for the ECU.
So be careful what you buy and check any claims that they are an alternative replacement part, the relays often have the circuit diagram on the case. I have bought these in the past from so called specialists and they have not been correct.
Cheers,
Simon.
Relays with diode protection are widely available, but they normally have the diode in parallel with the coil (across from 86 to 85) and I’m afraid I don’t know if this type of relay provides adequate protection for the ECU.
So be careful what you buy and check any claims that they are an alternative replacement part, the relays often have the circuit diagram on the case. I have bought these in the past from so called specialists and they have not been correct.
Cheers,
Simon.
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