Hello all,

I just purchased a 84 model, and was very happy with it for the first few days, then suddenly the fuel pump stopped running seemingly overnight.

So deciding this was probably a good time to upgrade to a 85 pump, I went ahead and pulled the pump, replaced it, and went to replace the relay (it was an original). When I went to replace the relay I found the connector cabling had pulled back, and all the wiring was green and overlapping. Got a new relay connector, and wired it back up. Pump would still not come on when turning the key.

Got out the multimeter and test light. The rear pump connection has 3 wires, a black ground I'm assuming (maybe thats part of my problem), a pink wire that seems to always be supplying around 10 volts until the key is turned off. (I'm guessing this is the fuel level sensor), and a blueish wire that when turning the key becomes hot for around 2 seconds and then dies. (This I assume is the correct hot wire for the pump) The issue I seem to be seeing though, is that this blue wire is only outputting around 6-7 volts vs the 10-12 range I would expect.

Now I've tested the pump by just directly hooking battery leads the connector, and it turns on and runs fine. What makes no sense to me though is if I wire up the pump and then probe the voltage with the key on, I get zero voltage, almost like it is short circuiting inside the pump.

This makes no sense to me though since direct battery connections work, and the pump spits out fuel.

Any assistance would be most appreciated.

Thanks

 

I can't help you but this link below might get you started
Good luck
Jim

http://forums.corvetteforum.com/show...fuel+1984+pump

 

So it seems like this was a wiring issue, running a new wire from the relay back to the pump has everything working. Car seems to also run a lot better with the 85 pump, but I have noticed that instead of idleing at around 600 rpm, I am now idleing at 900 in drive and around 1100 in park. Anyone know the cause of this?

Thanks

 

I don't like giving advice on different M.Y. Vettes as some things are not the same and bad advice will cause more problems down the road. Check link out below.
Jim

http://forums.corvetteforum.com/show...high+1984+idle