Aftermarket Fuel Pump? Any luck?

[MattP1976]

I replaced the fuel pump on my 04 4.6 back in July along with the fuel filter due to p0171/174 along with confirmed low fuel pressure. Car ran great and I drove it to Destin and back to Houston no problems. I used an aftermarket fuel pump through Amazon which may or may not have been a mistake but I digress...

1000 miles later I've got a po174 with lowish fuel pressure 35-37 PSI when Ford manual states 50 psi is normal at idle. I hate to drop a bunch of cash on an assembly but I'd rather not drop the tank multiple times.

Any luck with a good aftermarket pump that I can install into my assembly?

 

[Hamfisted]

If it's just a single P0174 code I would smoke check the intake system and look for a vacuum leak. It should be running fine at 35 psi at idle. As long as you see it bump up when you rev the motor. But Delphi, AirTex, Spectra, are good aftermarket choices if you actually end up buying a new one.



These are great little smoke machines if you need one ....
https://www.amazon.com/AutoLine-Pro...Mechanics+smoke+machine&qid=1601565514&sr=8-2



Variety of fuel pumps at Rock Auto ....
https://www.rockauto.com/en/catalog...fuel+&+air,fuel+pump+&+housing+assembly,10147

 

[MattP1976]

If it's just a single P0174 code I would smoke check the intake system and look for a vacuum leak. It should be running fine at 35 psi at idle. As long as you see it bump up when you rev the motor. But Delphi, AirTex, Spectra, are good aftermarket choices if you actually end up buying a new one.



These are great little smoke machines if you need one ....
https://www.amazon.com/AutoLine-Pro...Mechanics+smoke+machine&qid=1601565514&sr=8-2



Variety of fuel pumps at Rock Auto ....
https://www.rockauto.com/en/catalog...fuel+&+air,fuel+pump+&+housing+assembly,10147

It actually goes down when I rev it. I just performed the fuel pressure test again. 40 psi at idle drops to 35 when I rev it. I'm going to leave the gauge hooked up and drive it on the highway. Freeze frame shows the lean condition detected under 80% load or higher at highway speeds.

 

[GAINMOB]

order from rockauto on the vendor page...best prices...i put in an aftermarket fuel pump in 2010 and after i changed it i got a bad fuel relay switch...then the pressure switch went...i also got the code again when i needed to changed the plugs and cops stopped the misfires and corrected the codes

 

[MattP1976]

Update: under load the pressure drops to 25-27 psi. I left the gauge hooked up and went driving down the highway. Hard acceleration made the pressure drop from 40 to 25-27.

 

[Hamfisted]

Update: under load the pressure drops to 25-27 psi. I left the gauge hooked up and went driving down the highway. Hard acceleration made the pressure drop from 40 to 25-27.

Well, that's crap. It should climb in pressure a bit. Do you remember what brand fuel pump you used ? Does your Expy bog down trying to accelerate?

 

[MattP1976]

Well, that's crap. It should climb in pressure a bit. Do you remember what brand fuel pump you used ? Does your Expy bog down trying to accelerate?

It doesn't really feel like it's bogging down but it's never really had much power being a 4.6. I used an Amazon special fuel pump that I installed into my assembly. My concern is that it's not a 171/174 code. It's only showing lean on one bank.

 

[Hamfisted]

Yeah, that's why I would recommend smoke testing the intake system, and find the vacuum leak. It'll save you a ton of headaches using smoke.

 

[MattP1976]

Yeah, that's why I would recommend smoke testing the intake system, and find the vacuum leak. It'll save you a ton of headaches using smoke.

Yessir. I had to borrow a smoke machine to get the evap system under control. I guess I'll be borrowing one again.

 

[MattP1976]

After driving it some more, I ended up with the 171/174 codes. I went ahead and replaced the Amazon special pump with a Delphi unit and a motorcraft fuel filter. Now it has 53 psi at idle. I'm betting I'll be good now. I'll be test driving shortly.