yes you could have your toggle switch....but the whole idea is to remove power to the fuel pump in the event that the worse happens.....vehicle is crashed, driver unconcious, fuel pipe ruptured........pump still going. While the chances are small it wouldnt be prudent to have some switch which could be easily closed by the driving falling across it or some other cabin deformation.
electric fuel pumps
Started by
_RTS Guy_
, Jun 01 2006 04:44 PM
60 replies to this topic
#52
Tiny
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Posted 09 June 2006 - 06:51 PM
Ive got a toggle for my pump, and the reason i asked about priming and the tach relay was that it takes a GOOD 5 sec for my pump to prime and push fuel and to refill the float bowls... ( car only gets driven rarely so the bowls dry out).
Personally i'll fit the tachio relay to trigger my fuel relay, and also keep the toggle as a backup ( incase i dont even want the pump somehow).
Anyway each to their own, but i think theyre a good idea!
Cheers.
Personally i'll fit the tachio relay to trigger my fuel relay, and also keep the toggle as a backup ( incase i dont even want the pump somehow).
Anyway each to their own, but i think theyre a good idea!
Cheers.
#53
_devilsadvocate_
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Posted 09 June 2006 - 08:14 PM
There are a number of ways to get around the problem of the fuel pump running on if motor stops with the ignition on. The alternator method suggested is one(though personally ive never hooked anything up to the D+ terminal as such) and actually linking the fuel system to the proper operation of the alternator is just increasing your chances of being stranded roadside. ie if your alternator starts losing its ability to charge(ie warning light comes on), you can drive the car for about half an hour before the battery wont power the ignition anymore, if you�ve got the fuel system powered of it, about 10seconds!,
Using an oil pressure switch is another.
Both have their obvious problems in starting the car and need some primer switch with its obvious safety compromise to overcome it.
Either a vac operated switch or the tach relay offering the small on time for priming are specific built for the task(Tiny I dont think youd find anything on the market with a long enough priming tank to refill those 5 gallon float bowls, turning the ign from off to on a few times would work though ) and relatively inexpensive, so why add complications or compromises to the car.
Using an oil pressure switch is another.
Both have their obvious problems in starting the car and need some primer switch with its obvious safety compromise to overcome it.
Either a vac operated switch or the tach relay offering the small on time for priming are specific built for the task(Tiny I dont think youd find anything on the market with a long enough priming tank to refill those 5 gallon float bowls, turning the ign from off to on a few times would work though ) and relatively inexpensive, so why add complications or compromises to the car.
Edited by devilsadvocate, 09 June 2006 - 08:16 PM.
#54
LX2DR
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Posted 10 June 2006 - 12:09 AM
He said a MOMENTARY toggle.you could always have a momentary on toggle switch to prime it. what ever floats your boat
yes you could have your toggle switch....but the whole idea is to remove power to the fuel pump in the event that the worse happens
These are spring return off.
Even a spring return push button. (Aftermarket air horn button)
Heaps of options.
You have to hold your finger on these to make it work.
No safety issue here that i can see & simple.
#55
_Oldn64_
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Posted 10 June 2006 - 03:19 AM
Is it me or a relay off teh starter would prime??? Qhilest this would require the motor to turn over this would also build up oil pressure so that the motor starts with reasonable oil pressure.
Cheers
Cheers
#56
TerrA LX
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Posted 10 June 2006 - 03:27 AM
maybe run the tach relay and a momentary switch over ride for priming.
benifits would be that you cannot forget and leave it on and you can still check float levels, pressure and leaks without the motor running with a momentary switch.
benifits would be that you cannot forget and leave it on and you can still check float levels, pressure and leaks without the motor running with a momentary switch.
#57
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Posted 10 June 2006 - 04:44 AM
well yes I did say toggle switch, but was referring to the momentary switch suggested.........isnt all that needed is constant pressure on the switch and it will activate the pump........surely one can picture the scenario Ive suggested as to why even the momentary switch is not good for safety?yes you could have your toggle switch....but the whole idea is to remove power to the fuel pump in the event that the worse happens.....vehicle is crashed, driver unconcious, fuel pipe ruptured........pump still going. While the chances are small it wouldnt be prudent to have some switch which could be easily closed by the driving falling across it or some other cabin deformation.
Oldn64: you could run a relay from the purple starter wire to prime the pump, but there would be no doubt many here who would winge that they need four secs or so to get enough fuel pressure to start and wouldnt want to waste their starter etc.
Yes I know its really a good idea to get oil pressure b4 the motor starts but if the battery is going weak, youd probably be hoping to get it going with the 1st crank.
But here again, this system would require at least 2 relays (and a diode to stop your starter being activated by the second relay which keeps the pump going while the motor is running) is more complicated(more possible points of failure) than necessary.
alx76: the tach relay will give activate the pump while cranking the motor, if excessive priming is req, then turning the ign from on to off to on can be done as many times as necessary to get full priming(the tach relay will prime for ~2 secs each time ign is switched on)......surely this is not too much trouble rather than installing a death button
#58
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Posted 10 June 2006 - 05:32 AM
Would not require the diode as I already relay the starters in hodlens. gaurentees my car to start... if you are nto sure why thenyou obviously have never had the starter issues common to holdens. therefore would not need anything else as the ciruits are isolated anyway by design..well yes I did say toggle switch, but was referring to the momentary switch suggested.........isnt all that needed is constant pressure on the switch and it will activate the pump........surely one can picture the scenario Ive suggested as to why even the momentary switch is not good for safety?yes you could have your toggle switch....but the whole idea is to remove power to the fuel pump in the event that the worse happens.....vehicle is crashed, driver unconcious, fuel pipe ruptured........pump still going. While the chances are small it wouldnt be prudent to have some switch which could be easily closed by the driving falling across it or some other cabin deformation.
Oldn64: you could run a relay from the purple starter wire to prime the pump, but there would be no doubt many here who would winge that they need four secs or so to get enough fuel pressure to start and wouldnt want to waste their starter etc.
Yes I know its really a good idea to get oil pressure b4 the motor starts but if the battery is going weak, youd probably be hoping to get it going with the 1st crank.
But here again, this system would require at least 2 relays (and a diode to stop your starter being activated by the second relay which keeps the pump going while the motor is running) is more complicated(more possible points of failure) than necessary.
alx76: the tach relay will give activate the pump while cranking the motor, if excessive priming is req, then turning the ign from on to off to on can be done as many times as necessary to get full priming(the tach relay will prime for ~2 secs each time ign is switched on)......surely this is not too much trouble rather than installing a death button
Cheers
#59
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Posted 10 June 2006 - 07:19 AM
Yes, my apologies, correct ^, the diode wouldnt be necessary..........brain fade.
Edited by devilsadvocate, 10 June 2006 - 07:23 AM.
#60
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Posted 10 June 2006 - 03:15 PM
All I do when I havent started my car in a long time is turn ign on then off again & by the next time you turn the ign on again the lines will be primed besides you can hear it when it is primed.It's the same thing we do on new cars that have been sitting around out in hot weather for a month or two.
#61
Tiny
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Posted 10 June 2006 - 08:52 PM
I agree with what devils has said, and gtrboyy has said. To overcome the problem of a short "prime time", just turn the ignition on and off a couple of times. That's what i'll be doing!
Oldn: I also prefer to start the engine with oil pressure so i guage how good my battery is, and crank it BEFORE i prime the system to raise oil pressure.. THEN i activate my fuel pump.. let it fill er up, and then kick it in the guts.
Either way the safety of the tachiometric relay or oil pressure actvated switch is a really good safety device and i think its well worthwhile even if its an additional point of failure ( incorporated into an existing system like mine).
Cheers!
Oldn: I also prefer to start the engine with oil pressure so i guage how good my battery is, and crank it BEFORE i prime the system to raise oil pressure.. THEN i activate my fuel pump.. let it fill er up, and then kick it in the guts.
Either way the safety of the tachiometric relay or oil pressure actvated switch is a really good safety device and i think its well worthwhile even if its an additional point of failure ( incorporated into an existing system like mine).
Cheers!
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