i am using my stock fuel pump with a 1975 350 with a q-jet carb. i have the regulator and all that. my question is when i wire the fuel pump can i hook it staight to a switch and from the switch to a hot when the ignition is on? should i use a relay? i dont have any factory wiring hooked up so there is no reay hooked to the fuel pump. but i have the old relays, so how would i hook it up if thats what i need to do? thanks alot RICH
The simplest, and possibly the safest thing would be to reinstall the fuel pump relay circuit. Charles
i would if i knew how to wire it. can anyone tell me how to wire the relay? thanks for any help RICH
This isn't a personal attack, so don't take it as one. When swaping engines, never hack out a wiring harness, then realize you just screwed the dog.
People do this all the time and it drives me insane. I don't have the wiring diagram for an 87 Camaro. I don't know what color the wires are for the fuel pump, I don't even remember which relay terminals do what.
The simplest solution is to get a compleate fuel pump wiring loop from a salvage yard. And next time don't hack out wires. If all those wires, emmissions controls, and "computer" stuff baffles you, ask someone.
People constantly ask me this stuff day in and day out, and get offended when I don't remember the eiring diagrams for every car. Charles
when swaping out the 2.8 v-6 mpfi motor for a 1975 350 chevy with a carb, theres no reason not to hack it all out. if you dont theres just a million unused wires laying under the hood.
Actually what I do is to use a V8 engine harness when doing conversions like that. I don't hack the V6 harness, I remove it, and sell it. I only hack harnesses out of cars heading to the crusher, for the copper. Charles
what i did was remove all the harness going to the computer. and i sold the harness and computer. but the relay went to the computer so thats why i removed it. also i did not plan on using the stock fuel pump, i was going to use a mechanical fuel pump but i do not look forward to droping the gas tank.
You are going to have to locate the fuel pump power and ground wires. Coming from the tank. Then you will need to run a ground wire for the relay, and a power wire from the fuse block (reuse the fuel pump fuse), so that it turns on and off with the key switch.
You will probably need to find a wiring diagram to find which wire is the hot and which is the ground. Aftermarket wire in relays should come marked where to hook the hot & ground wires. Charles
Why not? When you're driving it's on, when you're not driving it's off and the regulator regulates. They use a switch for racing, and I use one myself on my '89. Just one thing... remember to shut off the switch, or you'll be coming back to a dead battery. ;) Not that I know...... Good luck.
thats how i have it hooked now. only that mine i hooked it to a hot when the ignition is on, so if i forget to shut it off my battery is not dead and the motor is not flooded. i was told that this was not a good idea with out a relay? i have not figured out why? besides if i roll it it will keep pumping fuel and feed a fire, but why the relay?
If you do that, you must make sure your wires, fuse and switch can handle the current involved.
If you want to go the relay route, the coil side of the relay is switched and the contacts are, well, like a mechanical switch.
One side of the contacts go to the battery with the other going to the fuel pump. Ground still goes to the negative side. One side of the coil goes thru a switch to +12 and the other side goes to gnd.
NOI
Some cars are setup so that if they experience a shock above a certain g-level, they trip a safety that cuts off the fuel pump. Ferd, for instance, does this as part of their fuel pump relay assy. Get rear ended or roll? Pump is off.
From where I sit, if you have a switch that can handle the current draw, I don't see much of an issue from a personal standpoint.
/me will think it over today.
NOI
Original poster: Get a wiring diagram. $25 from Alldata.com
NOI: Correct on Ford. It is called a "fuel pump inertia switch". I've stopped at many a fender bender involving a Ford and got the "bumpee" going again by resetting the switch. LOL.
Charles & others: You can buy aftermarket add in inertia switches at many parts stores. They are a universal type replacement item.
Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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