desoto1939 Posted June 3, 2010 Report Posted June 3, 2010 Over the weekend I was replacing an old single wire 6v Electric fule pump with the newer style Airtex 6v two wire electric pump. Points to remember if someone else uses this pump. My 39 Desoto and most of our cars and trucks have a 6v positive ground system. This is the most important part to remember because I will come back to this point. The pump has two wires attached to the one end of the pump. One wire is labeled as the + and the other is labeled as the -. In the instruction sheet it states to attach the + wire to your power source or switch and the - tot he ground. But when you do this the unit will not work. Remeber that if your car or truck is a positive ground then you have to change how the wires are hooked up. The unit has an internal selinoid for pumping. Since the frame is the positive then you need to attached the wire that is marked as + on the unit to the frame or your grounding connection and then take the wire that has the - and then hook this to your power source or switch. Then unit will work. I originally had it hooked up the other way as per the instructions then when changing to the wires then the unit worked. Also note that on this pump it will not stop pumping when the bowl has been filled like some of the other style pumps. This is a good pump to get the engine primed to get gas from the tank to the carb so you do not have to grind the engine and also wear down the battery. The pump is very quiet when operating. So you will only need it to run for a short time maybe 15-20 seconds to get the gas up to the carb. If you you need any more information or specifics please feel free to contact me at Desoto1939@aol.com. The use of the electric pump also helps if you ever get a vapor lock and need to push gas up to the carb and also is a back up in case you mechanical pump fails. Knowing the grounding of your car is the key to the installation on this style pump. If you have Postive grounf then the positive wire on the pump goes to the ground if you have negative ground then the negative wire goes to ground. Hope this helps. Rich Hartung Desoto1939@aol.com Quote
JBNeal Posted June 3, 2010 Report Posted June 3, 2010 didja mount to the motor or to the frame? just curious I reckon... Quote
desoto1939 Posted June 3, 2010 Author Report Posted June 3, 2010 When mounting these electric fuel pumps they should be mounted as close as possible to the fuel tank. These type of pumps are a pusher pump and not a puller pump. They work best when pushing hte fuel and not pulling the fuel. i mounter mine along the frame of the car just in fron of the rearend. I used a location inwhich the fuel line runs up along the left side of the car. This provide a flat serfurace to mount the pump and also provides me witht he opportunity to have a visual check on the pump but is hidden under the car. You have to get down and look under the car to see the pump from the passenger side of the car. i do know that some owners are usin ghte electric pumps in the vacuum tanks in the older cars that did not have the mechanical fuel pumps that we have in the cars now. Rich Hartung Desoto1939@aol.com Quote
Powerhouse Posted June 4, 2010 Report Posted June 4, 2010 hey there, I installed one of those pumps and need to leave it on all the time. Is that because I don't have a manual pump as well? Quote
oldmopar Posted June 5, 2010 Report Posted June 5, 2010 I installed one last year in the suburban it is the only pump I use but being lazy I hooked it up on the right inner fender and it pumps fine. Quote
Jerry Roberts Posted June 5, 2010 Report Posted June 5, 2010 hey there, I installed one of those pumps and need to leave it on all the time. Is that because I don't have a manual pump as well? Yes . Quote
BeBop138 Posted June 5, 2010 Report Posted June 5, 2010 I am using a similar pump and is on all the time also. I think you should use a fuel regulator and pressure gauge with these pumps also, they can put out more pressure than needed on some carbs, my two cents:D......Lee Quote
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