Down On PAH

[rleng1]

After 3 laps of Race 4 at Hallett, my car was down on power. Oil pressure fine, water temp ~ 220F. volts ~ 13v. Going down the straight after the Bitch, I usually run the car in 3rd gear to about 5600 rpm. After the 3rd lap, the car will only go to 4000 rpm. Same with the other straightaways.
I pulled into the pits, and I heard the fuel pump making a much louder than usual whining noise. After I turn the car off, and turn the power switch back on, I hear the fuel pump, but it is making a normal level of whine.
I went back out during the race, and it was doing the same thing, down on power, and when I returned to the pits, the louder whining noise was back.
The car starts fine and seems to run smooth, but down on PAH.
Any thoughts on what the issue may be, and how to go about finding the issue?
Thanks,

[ShadowBolt]

After 3 laps of Race 4 at Hallett, my car was down on power. Oil pressure fine, water temp ~ 220F. volts ~ 13v. Going down the straight after the Bitch, I usually run the car in 3rd gear to about 5600 rpm. After the 3rd lap, the car will only go to 4000 rpm. Same with the other straightaways.
I pulled into the pits, and I heard the fuel pump making a much louder than usual whining noise. After I turn the car off, and turn the power switch back on, I hear the fuel pump, but it is making a normal level of whine.
I went back out during the race, and it was doing the same thing, down on power, and when I returned to the pits, the louder whining noise was back.
The car starts fine and seems to run smooth, but down on PAH.
Any thoughts on what the issue may be, and how to go about finding the issue?
Thanks,


Damn Randy, Jay had the same issue after about 30 minutes of R4. The car would not turn even 5000 RPM's in third or higher and reved very slowly. No miss or anything. We did not hear the F/P but I did add 1 gallon of fuel and he went back out. Even with the extra fuel the car had the same issue. Looking for what could be the same issue.

JJ

[K Shaw]

The fuel pump is crapping out on you. I gets hot and output drops and it cant keep up with the demands of the engine.

Well thats my idea any way. Get a fuel pressure gauge on it and see if the pressure drops off while beating on it.

kyle

[y5e06]

well, based on what you mentioned first thing to check would be your fuel pressure. bust out your gauge and check it with both the vacuum line connected and disconnected (if it has that. i'm oblivious on LS1 stuffs)

[Casey_SS]

Randy - this sounds like a text book case of 4th gen fuel pump failure. Those are all the classic symptoms and it's not an uncommon problem. Some guys go through one pump a year, others get 2-3 years out of them but they all die eventually and this is how it usually happens.

[Rob Liebbe]

I don't know about the GM stuff, but Marshall did a "scientific" test a while back on the Fords and found the O'Reily pumps to be more durable than the Autozone pumps. This was confirmed by installation and no further fuel pump problems using the O'Reily parts. The Autozone pumps were dying at an alarming pace.

[ShadowBolt]

When I got the car from Tony he had just installed a SVT Focus pump. If failed after a year (where we never had a fuel issue until the pump died) and I installed a new stock Mustang GT pump. Several times this year if Jay ran a session or race and I did not need the weight I would try to go out with the tank being down 3.5 to 5 gallons. I had fuel starvation a few times after a few laps so we started just filling the tank for each session. If it was just fuel pick-up problems adding the gallon to Jay after 30 minutes of the race should have made it go back to okay for a least a few laps.


JJ

[Crumpacker]

Jerry, my old fox had those same symptoms and it turned out to be fuel pump. Very sluggish and wouldn't rev past 4500. Had pressure and ran fine at idle.

The LeMons neon had similiar issues and it was a clogged pickup screen and filter.


If it's fuel starve, it'll start coughing as your exiting extended right handers and get worse lap after lap... it'll run fine in lefts and straits.

[BryanL]

Ol English-it does sound like the fuel pump is going so putting a gauge on it would be good. You can run the gauge and tape it to your windshield if you need to test it under a load while hot of course similating the conditions isn't the easiest. You run the car full of fuel after every session? On the street idiots always burn up their fuel pumps running around with barely any fuel in the tank which ends up running hot fuel all the time and kills the pump. Or just pull out the restrictor!

JJ-I thought you had to have some super special variable volume fuel pump that was specific to that motor or remember something like that on Jeremy's?

[GlennCMC70]

OEM intank pumps only.

[Adam Ginsberg]

JJ-I thought you had to have some super special variable volume fuel pump that was specific to that motor or remember something like that on Jeremy's?

Close - starting in 1999, Ford changed the previous generation's return fuel system with a returnless system. The ECU manages voltage to the pump to control fuel pressure based on engine demand. They eliminated the return line, fuel pressure regulator, etc.

And I'll agree that it sounds like your fuel pump is giving up the ghost.

[rleng1]

Thanks for all the feedback, and I always run the tank full before every session.
Any special techniques anyone has for installing the trap door?
You guys are cool. I may need some help with this rash I'm developing.

[RichardP]

OEM intank pumps only.


Unless you have a really expensive fuel cell that sucks for fuel pickup and has to be replaced way too often...


BTW, the fancy variable fuel pump stuff is factory on late model returnless systems.


Richard P.

[GlennCMC70]

Unless you have a really expensive fuel cell that sucks for fuel pickup and has to be replaced way too often...


BTW, the fancy variable fuel pump stuff is factory on late model returnless systems.



Richard P.
Sorry for assuming folks w/ think I was refering to the OEM tank.

[ShadowBolt]

Sorry for assuming folks w/ think I was refering to the OEM tank.

I thought you were saying the SVT Focus pump was not okay. have a stock GT pump now anyway.


JJ

[GlennCMC70]

If the SVT Focus pump is not the same part number as a XX year Mustang GT pump, then its not.

[Alien]

Actually, as long as it fits in place of the GT pump, it is.

7.22 Fuel System
7.22.1 A maximum of one fuel pump and one pickup are allowed with the following restrictions:
1. Cars retaining the stock fuel tank may use any fuel pump that fits in the factory location.

[GlennCMC70]

I stand corrected.
Thanks.

[mitchntx]

Actually, as long as it fits in place of the GT pump, it is.

I didn't look it up, but I knew that to be the case.

I have a 3G pump in my car because it costs $30 and is available at any parts store and not a $250 dealer only item.

[marshall_mosty]

I don't know about the GM stuff, but Marshall did a "scientific" test a while back on the Fords and found the O'Reily pumps to be more durable than the Autozone pumps. This was confirmed by installation and no further fuel pump problems using the O'Reily parts. The Autozone pumps were dying at an alarming pace.I sure did... 2006 was my "season from HELL" on killing pumps. Went through six in one season and two in one weekend. I ended up solving the problem by switching from AutoZone pumps to O'Reilley's. Just for the hell of it, I ran an AutoZone pump on the garage floor attached to a battery charger and ran it dry until it died.... 30 minutes. Did the same test on a new O'Reilley's pump and it lasted something like 2 hours. Don't remember the exact time, but was enough to convince me to go the O'Reilley's route...

Now that I carry a spare and have an O'Reilley's pump, I haven't had any issues....

[Alien]

Any thoughts on what the issue may be, and how to go about finding the issue?
Thanks,
Sorry I'm late in offering help Randy, but did you check the fuses?

:D

[rleng1]

Yes Gary, the fuses are fine. Thanks again for working on my car and getting it running. Still loking for a test dummy ( driver). Al didn't work out as well as planned.

[ShadowBolt]

Yes Gary, the fuses are fine. Thanks again for working on my car and getting it running. Still loking for a test dummy ( driver). Al didn't work out as well as planned.

I think Al is a fine test dummy. Don't let him talk about you like that Al.

Jig-a-clean forever!

JJ

[Rob Liebbe]

Yes Gary, the fuses are fine. Thanks again for working on my car and getting it running. Still loking for a test dummy ( driver). Al didn't work out as well as planned.

I know a guy.