fuel pump problem
fuel pump problem I put ls1 in 94 chev p.up. I changed the low pressure intake pump to the correct pump and used the stock wiring and relay from the 94. It worked fine for a couple of weeks...now the pump seems to have quit. My question is could it have burned out due to the wire being too small to handle the extra current from the higher pressure pump? Does anyone know the wire size for a stock ls1 hot wire? Thanks in advance. Chuck
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
I would like to place my bet on the hose between the pump and sender.
You didn`t say if you could hear the pump running and it just didn`t have pressure or if it wasn`t running at all. But if you can hear the pump run and just don`t have pressure then its time to drop the tank. I am guessing that you probably re-used the little piece of rubber hose that was between the old pump and sender, because the new pump didn`t come with it. That hose has a tendency to blow out with the increased pressure and the pump will run but you won`t have pressure. Guess how I figured this one out.......if thats the case you are not the first person to have this happen and won`t be the last.
I don`t think that you burned out the wiring/relay for several reasons
1. You didn`t mention that you put an larger fuse in. So you couldn`t have burnt the wiring up because the fuse would have gone first as long as it was the same amperage as the factory installed.
2. The relays are almost all the same 30A bosch style units
3. The fuel pump should draw less than 20A, I used a 14 gauge wire for mine, and I don`t think I have ever seen a GM car that used a wire smaller than 14 gauge for the fuel pump, didn`t matter if it was a TBI,TPI, LT1, or LS1 car.
You didn`t say if you could hear the pump running and it just didn`t have pressure or if it wasn`t running at all. But if you can hear the pump run and just don`t have pressure then its time to drop the tank. I am guessing that you probably re-used the little piece of rubber hose that was between the old pump and sender, because the new pump didn`t come with it. That hose has a tendency to blow out with the increased pressure and the pump will run but you won`t have pressure. Guess how I figured this one out.......if thats the case you are not the first person to have this happen and won`t be the last.
I don`t think that you burned out the wiring/relay for several reasons
1. You didn`t mention that you put an larger fuse in. So you couldn`t have burnt the wiring up because the fuse would have gone first as long as it was the same amperage as the factory installed.
2. The relays are almost all the same 30A bosch style units
3. The fuel pump should draw less than 20A, I used a 14 gauge wire for mine, and I don`t think I have ever seen a GM car that used a wire smaller than 14 gauge for the fuel pump, didn`t matter if it was a TBI,TPI, LT1, or LS1 car.
I do not think it was running but I will check closer cause the hose could be it. Thanks for the help...also (for anyone changing fuel pump in pickup) lifting the box off the frame is a very easy way to get access to fuel pump if you have a pickup. Thank you for the info and suggestions.
As usual it turned out to be something weird. The connector that connects the inside wires to the underside of the tank surface was faulty...the little tabs were flattened out and not making good contact.
