QuestionQUESTION: it has exterior fuel pump is this going to hum before cranking the engine? it has no voltage with key just turned forward but when cranking gets about 10 volts, normal? disconnected fuel line does pump fuel up when cranking. but only once did the fuel pump hum and sent fuel in accessory. mode. what is the fuel pump suppose to do? can only find one fuse box at pass. kick panel doesn't say anything about fuel pump or other engine stuff is there another fuse box?
ANSWER: Chris
At the start , the fuel pump should spin up and presurize the system , you can usually hear it. The fuel pump should continue to run when car is started , it needs a presurized system. There is a fuel pump relay , you need to check that ,should be in the fuse box area, larger black looking ( or silver) box
I think the 78 also had a safety circuit in the engine bay , passengers side , mid intake that will shut off the fuel pump in the event the car turns over. Looks like a plug with a two prong connection. Disonnect that and see if the pump runs and car starts, may be a bad sensor
Good Luck
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QUESTION: what about it only getting voltage while cranking the engine. when the key is turned forward nothing but when cranking gets 10 volts. normal? should it get volts when just turned forward. checked for relay/fuses only fuses i could find was in the kick panel on pass. side where else can i look if you think fuse or relay. kind of weird that it gets volts and pumps up fuel when cranking. but nothing when key just turned forward.
ANSWER: yes it should, it shuld pressurize the system when the key is in ACC position. Relay if not in fuse box ( silver box ) then behind glove box under control panel/ Are you getting fuel to the fuel rails?
Sounds to me like a bad fuel pump, was this a sudden onset or gradual onset of problems
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QUESTION: i am only getting fuel to the rails when cranking the engine. don't get fuel when in the ACC position but don't get voltage to the fuel pump either. this was a sudden problem. i can only think from what you say if i am not getting voltage or fuel to the rails when in the ACC position it would have to be a fuse or relay. where is the (silver) box can still only find the one in the kick panel behind the trim on the passenger side.
AnswerIt should be above and to the right of the fusebox. The easiest way to identify it is to find the large red/white/black wire that runs from it to the fuel pump.
on some it is behind the glove box, but most of the time you have to take the whole kick panel off . Some models it is the one in the top left hand corner . BTW putting a jumper between 1 and 3 poles should turn on the fuel pump
Can also be behind glove box
and since it is a generic relay , it could be black and not silver
