i was driving my olds today going to get a stupid computer worked on, pulling in thwe parking lot and she shut off so i turned the key off and back on and noticed the fuel pump was not running. went in got my work done and came back out planning to walk home to get tools and spare pump, i got in just to see if it was doing the same thing and the pump was running so i drove home quickly before it shut off again. its a holley red pump wired to a 30 amp relay(purchased from radio shack). every time i think i have this car fixed it does somthing random like this wtf. any help is appreciated.
Could be many things. A bad relay is one of them, but it could also be a bad ground (very likely) or loose/poor wiring connections.With intermittent problems like this you need to start at the power souce and work your way back to the pump, or vise-versa. If it happens again, run a jumper to a good ground then to the pump body, provided that is how it gets it's ground. Then do the same with the pump positive input and a good positve source.
Holley electrics are intolerant of debris and often have several mini failures before the final ****. Despite having been around forever the engineering and durability is unchanged, I gave up on them for street cars about ten years ago. When it happens again, turn the key on and literally thump the pump. good luck
Do you have good voltage at the pump? If the battery reads 12.2 volts with engine shut off, the pump should read the same or not less than 12.1 volts. Holley's are affected by heat, whether sefl-induced from low voltage as well as where they're located. If you have the pump close to exhaust components, move the pump or shield it. A flow of air to the pump helps as well. If all that's ok, pull the pump internal regulator and see if it's sticking. If so, polish the bore with some 320 wet/dry, re***emble and give it a try. When I've had problems with Holley pumps it's been heat or low voltage related. 11 volts is low voltage. What's working well for me now, electricity wise is: 14 gage control wire to the relay. 10 gage power supply wire to relay. 14 gage wire from relay to pump - put the relay fairly close to the pump. This will give you the same voltage at the pump as the battery reads. I'd be su****ious of the Radio Shack relay. Go to a real parts house and get a good one. Make sure it's for 'constant duty.' The ones I buy are all steel contruction and no plastic. Shifty has an excellent point about dirt etc. Run a good flowing filter between tank and pump. As Bob37 notes, a bad ground has been the cause of many an electrical woe....
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