Fuel Pump Module Quirk

PeeDeeSuave

New member
3
0
0
I am having trouble with a 2005 Vibe fuel system. I replaced the fuel pump module because the car has low power and 183000 miles. It was running only minutes before. When I tried to start it there was no power to the new pump. I checked all fuses and relays. I re installed the old pump and no electrical power as well. Finally I powered the pump via a 12V tip positive cigarette lighter plug with the black and red jumper wires off of a Craftsman electrical tester. The leads fit perfectly in the plug of the module and the lead point fits right in the 12V cig tip and easily reached the back seat. The pump built pressure by touching the jumper for a few seconds until the pump sound changed slightly and I then touched the wires only for a few seconds at a time. I started the engine and it smoothed out and idled fine. After a couple minutes I shut off the engine and reconnected the plug. It ran and is still running. What would tell the pump to pump when pressure is low and high? I'm told this is through the ecm but what tells the ecm?
Also, this all started because the engine lacks power. It seems to surge and has more power when you back out of the throttle on acceleration. Had the problem prior to the new plugs. I have seen other posts with similar problems but no solutions.
 

melsg5

Staff member
SUSTAINING MEMBER
21,828
233
63
Did you disconnect the battery before changing the pump? Did you do a fuel pressure test before changing the pump? Did you check the engine compartment fuse box and looked at the EFI fuses and relay noted on page 5-99 of the owners manual?
 

PeeDeeSuave

New member
3
0
0
No

No I didnt check the pressure. I wanted to change it because of the mileage anyway. I will though because it runs just like it did and not a bit better.
I did check the fuses and relay. I did not disconnect the battery. Meant to but forgot. If that was the problem I would be very disappointed in Haynes for not making a big warning note on that. The car runs. I have driven it all week for hundreds of miles but its just like it was. But my question is what would tell the pump to pump when pressure is low and high? Does the pump run all the time or is there something that tells it to turn off and on. If the ecm does that what tells the ecm that the pressure is too low and to turn off the pump and likewise what tells the ecm the pressure is enough to turn the pump off?
 
Last edited:
Top