Electrical gremlins
Asked by Reaper25511 Aug 14, 2019 at 09:56 PM about the 2004 Pontiac Aztek GT
Question type: Maintenance & Repair
Have a 2004 Aztek rally edition. The main body buds went
bad replaced it along with the wiring harness plug. Installed
a new fuel pump, changed relays, changed fuses even
though they were good, starts about 8 or 9 times then
wont start, drop tank it will start again 8 or 9 times the quit.
Not getting fuel because starting fluid sprayed into throttle
body and it will start. BCM ECM bad fuel pump?
17 Answers
lincolnscott49 answered 5 years ago
Okey you should here the fuel pump come on when the key is turned on for a second and stop when the system is pressurized. Have someone turn on the key while you are close to the tank to listen and see if it turns on and goes off. Also do you have a fuel rail bleeder where you would connect a pressure gauge to? If so turn the key on and push the bleeder like you were trying to let air out of a tire to see if the system is pressurized and fuel comes out. If fuel pump comes on does it turn off soon after pressurized or stay on? If it stays on the problem is the ECM or at least was on one of my vehicles in the past where the two bottom pins that are the left and right bank grounds for the injectors were faulty. Also there is a fuel pressure regulator valve that could be bad. Let me know if you here the pump turn on go off or stay on and if the system is pressurized after it turns off. The problem could be ECM or regulator. also let me know if you here a click in the EFI relay when the key is turned on.
Reaper25511 answered 5 years ago
Yes fuel pump cycles as it should, checked that first. Checked for pressure it has 0. Changed relay to rule that out. The one idd thing I noticed, when I changed the fuel pump and replaced the wiring busses it would start with the tank down. When I bolted the tank up it still started, once I dropped it flat off the Jack's it would start 4 or 5 times and then never start again. Beginning to wonder if it's a faulty pump. It just doesn't make sense
lincolnscott49 answered 5 years ago
OK last resort. see if it has pressure at the fuel filter. Disconnect it and it should spew pressurized fuel. Leave disconnected and turn key on for a second to see if fuel comes out. I can think of nothing else either .
Reaper25511 answered 5 years ago
Respliced all wires 3 times. When not starting no pressure at filter either checked that as well
Reaper25511 answered 5 years ago
Pulled harness from pump traced back to the bus no visual breaks , pinches or defects
lincolnscott49 answered 5 years ago
If the pump is coming on and shutting off a few seconds after the key is turned on it should be pressurized before the fuel filter. Not after if the filter is clogged, if not something is wrong with this stupid fuel pump. I just cant figure this one out either. I hate to say it but the only way to be sure it isn't the pump is to replace it. Why in the hell did they put them in the friggen tank ?
lincolnscott49 answered 5 years ago
could you have spliced any wires wrong ? I just don't know. it sounds like a clogged line from the pump to the filter
lincolnscott49 answered 5 years ago
let me know if you find the problem and what it was. its like the pump is coming on but not pumping fuel
Reaper25511 answered 5 years ago
The pump is brand new. Matched wire for wire so nothing is cross wired. Ha e not changed the filter yet, but cant figure why it would be positional. But going to try that and already ordered another pump only thing I can come up with at this point