Need help with Fuel Pump ASAP!

VeNuM · 02-10-2003, 10:20 AM

My fuel pump or fuel pump relay died. My car is a couple miles away at my friends house so I have to get it towed to mine. Turn the key to the on position, fuel pump does not whine and prime the system. It's freezing cold out and snowing so working on dropping the tank and such at his house can't be done. Can someone tell me how to change the relay? I ran a search and came back with nothing. Or can I bypass the relay temporarily to get the car home? I'm just hoping it's the relay and not the pump. Right now I'm in school and am going to get a tow or try to get it running tonight. Please help! ~Brian

ChunkFunky · 02-10-2003, 10:26 AM

The only thing I'm going to ask, is if you tested the cutoff switch in the trunk, I've heard stories of it shutting off due to bumps, it can save alot of hassle if that IS the case... but I wouldnt get too excited yet..
-as

bigred90gt · 02-10-2003, 10:42 AM

The fuel pump relay should be under the drivers seat. I have never changed one out, but I would imagine it would involve buying a new one, unplugging the old one and plugging in the new one. Sounds relatively simple, but once again, I have never done it so I am not sure if anything else is involved. Have you pulled your codes? If it is the relay or the pump, I would think you would have codes.

Caymon

VeNuM · 02-10-2003, 11:05 AM

Please, call me stupid but there's a cutoff switch in the trunk? Where is this located and what does it exactly do? ~Brian

drudis · 02-10-2003, 11:14 AM

See the green-doohickie under the driver's seat on the floor, thats the relay for my 1989 Mustang.

There is also the "rear end collision switch" that is located near the back hatch latching mechanism. It looks about 1"x1" and has a plunger to reset it.

p.s. I have a stock fuel pump with like 25K miles on it. email me drudis@ford.com

VeNuM · 02-10-2003, 11:17 AM

Looks like I'll be taking the drivers seat out, any hints or tips on that? Thanks for that picture Drudis, helped a lot! ~Brian

ChunkFunky · 02-10-2003, 11:21 AM

like DRUDIS said, there's switch in the trunk, designed to stop the fuel pump in the event of an accident. it's never happened to me, but I've read about people's switch cuting off from hitting bumps. I "THINK" its on the drivers side behind the trunk molding.. but I have a vert, so it may be different.. should be labeled pretty well though. Though worst, case, it could also be bad.. so that's another thing to check if the realy is ok and you know the pump is ok too..

-as

VeNuM · 02-10-2003, 11:25 AM

Yeah, I'm going to check the switch, but I try to be prepared for the next step worst. I have heard from many people that the fuel pump relay likes to go out and I would imagine it's the original one on my car that has ~80k miles. I think it's too early for the fuel pump and the pump wasn't making funny noise, so I'm hoping it is that switch or at worst, the relay. ~Brian

ChunkFunky · 02-10-2003, 11:25 AM

The seat comes out EASY.. it's four bolts... or two bolts and two NUTS... though if you're lcuky you can get at it without taking the seat out... if you can reach under there... but like I said, worst case.. it's just 4 bolts, nothing a socket cant handle... you may need to pop off some plastic covers that cover the bolts... you can use a flat head screw driver to pop the little plastic RIVET things... whatever you call em.
-as

VeNuM · 02-10-2003, 11:32 AM

Can I just "plug-in" a new relay, or do I have to splice the wires together? ~Brian

bigred90gt · 02-10-2003, 12:22 PM

It should just plug in like any other relay, but dont quote me on that.

Caymon

Kamaro Killer · 02-10-2003, 01:51 PM

First, try to reset that switch in the trunk. If you open the trunk, look to the left of the hatch. There will be a hole about 1 1/2" wide that has a red button inside of it. Push the button down and try to fire up the car. I tried that and it didn't help, I had to replace my fuel pump. If/ when you replace the fuel pump, pay extra attention to the new seal that comes with the pump. I took my old pump out, and for some stupid reason thought I could re-use the old seal. I put the new pump in and there was fuel leaking out of the top of the tank for a day or two, before I had a chance to drop the tank and redo it again. The old seal completely ripped apart as I put the new pump in, so I had the pleasure of doing the job twice. Good luck, Keith

VeNuM · 02-10-2003, 07:21 PM

The switch didn't work and I was able to get access to the fuel pump relay without taking the seat out. Sent a friend to AutoZone to get me a new relay while I was in work, yeah, they sold him the wrong one after checking on 4 computers and 2 books, guess the part is just wrong. Heading up to Ford to get a replacement now. There anything wrong with putting in a 255 lph pump with a stock engine? I have plans of building a blown motor with lots of boost, but it won't be until next winter/year. Thanks to everyone whose been helping me out so quickly. ~Brian

VeNuM · 02-10-2003, 10:58 PM

Put my new relay in, still doesn't work. At this point I'm 99.999% sure it's the fuel pump, oh well, time to upgrade

Only thing is I don't have the money I need to buy everything, I guess my car is going to become a lawn ornament for a few days/weeks

~Brian

02-11-2003, 03:05 PM

Quote:

Originally posted by VeNuM
There anything wrong with putting in a 255 lph pump with a stock engine? I have plans of building a blown motor with lots of boost, but it won't be until next winter/year.

Yeah, a 255lph would be fine on a stock motor. The fuel pressure regulator regulates the psi., so it will work fine.

bigred90gt · 02-11-2003, 04:05 PM

lets say he does put in a 255 lph pump. With the stock fuel pressure and stock injectors, assuming he has the stock injectors, wouldn't that put a lot of un-needed pressure on his fuel lines? The residual pressure from the extra flow of the pump with the injectors unable to keep up would be a bit much, at least in theory. Just a thought.

Caymon

VeNuM · 02-11-2003, 07:39 PM

Caymon, you state a valid point, but shouldn't the adjustable pressure regulator fix that problem? ~Brian

bigred90gt · 02-11-2003, 07:55 PM

Quote:

Originally posted by VeNuM
Caymon, you state a valid point, but shouldn't the adjustable pressure regulator fix that problem? ~Brian

Dont get me wrong, I'm all for the extras and I dont even know if my theory is true. Its just a theory. With that said....

The FPR is the last thing the fuel sees before it hits the fuel rails. I wouldn't think the stress would be on the fuel rails anyways, considering most people run ~38psi pressure. The back pressure I was referring to is what you are going to have in the fuel lines between the tank and the FPR. You could always up the pressure at the fpr to compensate for the added pressure of the pump, but then you will run incredibly rich and thats not good. Its obvious that the 19 lb/hr injectors dont flow as much as the 24# and up. If you went with the larger injectors, again you would have to reduce the pressure at the fpr so as not to flood the cylinder with too much gas, which will result in even more backpressure in the fuel lines. Remember, this is all theoretically speaking. I may be way off in my thoughts. I'd say until you add the blower replace it with a stock unit, I cant imagine they are too expensive. But that is just what I'd do. If any of this "theory" is wrong, someone correct me please.

Caymon

VeNuM · 02-11-2003, 10:38 PM

Caymon, you have really made me think and I know it's a theory but it seems very practical. I'll talk to some people about a stock fuel pump and see if anybody else has anything to say about more pressure on the lines. ~Brian

Stang_Crazy · 02-12-2003, 01:20 AM

If you're really worrying about a stock replacement vs. the 255lph, just go with a stock replacement. You can probably find one for really cheap. If, sometime down the road, you decide to go the supercharger route you can always pick up a 255lph then. Mine only cost me $120.

02-10-2003, 10:20 AM	#1
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Need help with Fuel Pump ASAP! My fuel pump or fuel pump relay died. My car is a couple miles away at my friends house so I have to get it towed to mine. Turn the key to the on position, fuel pump does not whine and prime the system. It's freezing cold out and snowing so working on dropping the tank and such at his house can't be done. Can someone tell me how to change the relay? I ran a search and came back with nothing. Or can I bypass the relay temporarily to get the car home? I'm just hoping it's the relay and not the pump. Right now I'm in school and am going to get a tow or try to get it running tonight. Please help! ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 10:26 AM	#2
ChunkFunky Registered Member Join Date: Apr 2002 Location: Tustin, CA Posts: 465	The only thing I'm going to ask, is if you tested the cutoff switch in the trunk, I've heard stories of it shutting off due to bumps, it can save alot of hassle if that IS the case... but I wouldnt get too excited yet.. -as __________________ '89 GT Convertible: TFS TW Heads, TFS Street Intake, TFS Stage 1 Cam, FMS 1.6 RRs, 24# Injectors, Pro-M 75mm MAF, No Name CAI, 3.73s, O/R H-Pipe, FlowMasters, AOD w/ Trans-Go Shift Kit

02-10-2003, 10:42 AM	#3
bigred90gt 2 Stangs in the Stable Join Date: Apr 2002 Location: Baytown, TX Posts: 1,209	The fuel pump relay should be under the drivers seat. I have never changed one out, but I would imagine it would involve buying a new one, unplugging the old one and plugging in the new one. Sounds relatively simple, but once again, I have never done it so I am not sure if anything else is involved. Have you pulled your codes? If it is the relay or the pump, I would think you would have codes. Caymon __________________ '90 GT Under construction Best E.T. = Fast @ High Speeds - OK So I Lie. So What!!! 04 F-150 STX 4.2L 5 spd Rice Haters Club Member #128

02-10-2003, 11:05 AM	#4
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Please, call me stupid but there's a cutoff switch in the trunk? Where is this located and what does it exactly do? ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 11:14 AM	#5
drudis Moderator Join Date: Dec 1999 Location: Livonia, MI, USA Posts: 1,194	See the green-doohickie under the driver's seat on the floor, thats the relay for my 1989 Mustang. There is also the "rear end collision switch" that is located near the back hatch latching mechanism. It looks about 1"x1" and has a plunger to reset it. p.s. I have a stock fuel pump with like 25K miles on it. email me drudis@ford.com __________________ Darius Rudis, Moderator Corner Carvers Delight 1989 Mustang LX - Open Track Car http://www.dariusrudis.com

02-10-2003, 11:17 AM	#6
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Looks like I'll be taking the drivers seat out, any hints or tips on that? Thanks for that picture Drudis, helped a lot! ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 11:21 AM	#7
ChunkFunky Registered Member Join Date: Apr 2002 Location: Tustin, CA Posts: 465	like DRUDIS said, there's switch in the trunk, designed to stop the fuel pump in the event of an accident. it's never happened to me, but I've read about people's switch cuting off from hitting bumps. I "THINK" its on the drivers side behind the trunk molding.. but I have a vert, so it may be different.. should be labeled pretty well though. Though worst, case, it could also be bad.. so that's another thing to check if the realy is ok and you know the pump is ok too.. -as __________________ '89 GT Convertible: TFS TW Heads, TFS Street Intake, TFS Stage 1 Cam, FMS 1.6 RRs, 24# Injectors, Pro-M 75mm MAF, No Name CAI, 3.73s, O/R H-Pipe, FlowMasters, AOD w/ Trans-Go Shift Kit

02-10-2003, 11:25 AM	#8
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Yeah, I'm going to check the switch, but I try to be prepared for the next step worst. I have heard from many people that the fuel pump relay likes to go out and I would imagine it's the original one on my car that has ~80k miles. I think it's too early for the fuel pump and the pump wasn't making funny noise, so I'm hoping it is that switch or at worst, the relay. ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 11:32 AM	#10
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Can I just "plug-in" a new relay, or do I have to splice the wires together? ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 12:22 PM	#11
bigred90gt 2 Stangs in the Stable Join Date: Apr 2002 Location: Baytown, TX Posts: 1,209	It should just plug in like any other relay, but dont quote me on that. Caymon __________________ '90 GT Under construction Best E.T. = Fast @ High Speeds - OK So I Lie. So What!!! 04 F-150 STX 4.2L 5 spd Rice Haters Club Member #128

02-10-2003, 01:51 PM	#12
Kamaro Killer Mustang Enthusiast Join Date: Mar 2002 Posts: 528	I just replaced my fuel pump last week First, try to reset that switch in the trunk. If you open the trunk, look to the left of the hatch. There will be a hole about 1 1/2" wide that has a red button inside of it. Push the button down and try to fire up the car. I tried that and it didn't help, I had to replace my fuel pump. If/ when you replace the fuel pump, pay extra attention to the new seal that comes with the pump. I took my old pump out, and for some stupid reason thought I could re-use the old seal. I put the new pump in and there was fuel leaking out of the top of the tank for a day or two, before I had a chance to drop the tank and redo it again. The old seal completely ripped apart as I put the new pump in, so I had the pleasure of doing the job twice. Good luck, Keith __________________ 1993 GT 5.0-My Stang Rice Hater's Club Member 22

02-10-2003, 07:21 PM	#13
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	The switch didn't work and I was able to get access to the fuel pump relay without taking the seat out. Sent a friend to AutoZone to get me a new relay while I was in work, yeah, they sold him the wrong one after checking on 4 computers and 2 books, guess the part is just wrong. Heading up to Ford to get a replacement now. There anything wrong with putting in a 255 lph pump with a stock engine? I have plans of building a blown motor with lots of boost, but it won't be until next winter/year. Thanks to everyone whose been helping me out so quickly. ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-10-2003, 10:58 PM	#14
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Put my new relay in, still doesn't work. At this point I'm 99.999% sure it's the fuel pump, oh well, time to upgrade Only thing is I don't have the money I need to buy everything, I guess my car is going to become a lawn ornament for a few days/weeks ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-11-2003, 04:05 PM	#16
bigred90gt 2 Stangs in the Stable Join Date: Apr 2002 Location: Baytown, TX Posts: 1,209	lets say he does put in a 255 lph pump. With the stock fuel pressure and stock injectors, assuming he has the stock injectors, wouldn't that put a lot of un-needed pressure on his fuel lines? The residual pressure from the extra flow of the pump with the injectors unable to keep up would be a bit much, at least in theory. Just a thought. Caymon __________________ '90 GT Under construction Best E.T. = Fast @ High Speeds - OK So I Lie. So What!!! 04 F-150 STX 4.2L 5 spd Rice Haters Club Member #128

02-11-2003, 07:39 PM	#17
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Caymon, you state a valid point, but shouldn't the adjustable pressure regulator fix that problem? ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-11-2003, 10:38 PM	#19
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	Caymon, you have really made me think and I know it's a theory but it seems very practical. I'll talk to some people about a stock fuel pump and see if anybody else has anything to say about more pressure on the lines. ~Brian __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

02-12-2003, 01:20 AM	#20
Stang_Crazy It's never clean enough! Join Date: Jan 1999 Location: Shaler, PA Posts: 1,542	If you're really worrying about a stock replacement vs. the 255lph, just go with a stock replacement. You can probably find one for really cheap. If, sometime down the road, you decide to go the supercharger route you can always pick up a 255lph then. Mine only cost me $120. __________________ ~Dan 2001 SVT Lightning 89' GT : Taking up garage space and waiting for a buyer... Rice Hater's Club - Member #11

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