FPDM Thermal Overload

[Coderedsaleen]

:shrug: Can I anyone help me out with this? I have FPDM that continues to go into thermal overload and shuts the pumps off and on. The car idles up and down like it is going to stall, then it finally does stall. I let it cool down and it runs fine. Then once again it gets hot and repeats the shut down process again. Any help would be much appreciated. :shrug:

 

[mystichrome_kb]

give us more information on your fuel system. what kind of pumps, bap, etc

 

[Coderedsaleen]

give us more information on your fuel system. what kind of pumps, bap, etc

Did a engine conversion from 2001 2V to a 2003 4V SC. All factory wiring from front to rear. 2001 FPDM, 2003 Cobra tank w/ pumps.

 

[Coderedsaleen]

Anybody have any ideas? :shrug:

 

[mystichrome_kb]

if iam not mistaken 2001 cobras had only one pump. the 03-04 had dual pumps. did you also replace the fpdm?

 

[03 Indy Cobra]

I would first start with getting an FPDM from an 03-04 Cobra. If the 01 only has one pump like mystichrome kb says it seems like the 03 pumps need more voltage. Voltage that the 01 FPDM can't supply. There for thermal overload. I am not sure if the 01 only has one pump but I am sure someone who knows will chime in. We have this problem when we swap our Cobra pumps with the Ford GT40 pumps and we don't run a modified FPDM or run a dual FPDM set-up.

 

[03 Indy Cobra]

One more thing if you need the 03-04 FPDM call Steve from Tousley Ford he will give you the best price.

 

[Black306]

'99-'04 Mustang FPDMs are the same for V6s, GTs, Bullets, Mach 1s, and Cobras.

Give us a complete change over and modification list even if you don't think it'll matter. There is no such thing as too much info.

Data log your fuel pump duty cycle and fuel pressure. If it is a thermal shutdown caused by excessive current to the pumps, then your duty cycle should be maxed and your fuel pressure is going through the roof. If that is the case, then you have another problem. If not and it's not getting hot because of excessive current, then you might have a bad FPDM.

 

[Coderedsaleen]

'99-'04 Mustang FPDMs are the same for V6s, GTs, Bullets, Mach 1s, and Cobras.

Give us a complete change over and modification list even if you don't think it'll matter. There is no such thing as too much info.

Data log your fuel pump duty cycle and fuel pressure. If it is a thermal shutdown caused by excessive current to the pumps, then your duty cycle should be maxed and your fuel pressure is going through the roof. If that is the case, then you have another problem. If not and it's not getting hot because of excessive current, then you might have a bad FPDM.

List of change over / modifications:

1. 03 Cobra engine.
2. Using all 01 factory wiring harnesses, PCM, and Cluster.
3. Changed polarity on the COP.
4. Changed fuel tank w/pumps to 03 Cobra.
5. Wired FPDM the same as it would be on a 03 Cobra (Dual DG/YW wires from the CCRM for the FPDM signal wire).
6. Wired dual wires to the fuel pumps just like a 03 Cobra. (Dual positive and negative to send more voltage/amps (Upgrade)).
7. I have wired a relay to provide constant battery power to the FPDM, switched by the CCRM to activate the relay. Same as in the dual FPDM set up but only with one FPDM.
8. I have tried two different FPDM, original 01 and the 03, with the same effects.
9. Data logging I get 100% duty cycle, pumps maxed out. The voltage is 12.9 or lower. This is at idle or driving it.
10. Line 9 is why I did line 7. I have 12.5 - 13.7 now coming from the battery to the FPDM depending on state of the alternator.
11. Alternator voltage is reading 13.7 down to 12.5 at the battery, Should the voltage be reading higher, say around 13.9 constant? I was going to get a new alternator but the auto parts store has the 110 amp, should I be looking at getting a 130 amp? Which one it the original amps, 110 or 130?

Could I have one bad fuel pump? I know that when I turn the key on I hear the CCRM click but not the pumps, and fuel pressure is not showing on the electrical gauge I have installed. I turn the key on and off a couple of times and then try to start it, the car will start up and run. I have about 20-25 PSI fuel pressure while it is running. After it has been running for about 5 min the FPDM with heat up and start to go into thermal overload. This shuts the pumps off and on, I can see the pressure drop and rise when it does this.

So the only problems now are why does the FPDM go into thermal overload, weak fuel pressure and do I have a bad pump or pumps?

:shrug:

 

[Black306]

>> 4. Changed fuel tank w/pumps to 03 Cobra.

Is it a stock Cobra setup? Meaning, stock hat, stock pumps, PPRV in place? Or have you done any modifications to it?


>> 5. Wired FPDM the same as it would be on a 03 Cobra (Dual DG/YW wires from the CCRM for the FPDM signal wire).

Couple things here. First, a Cobra does not have dual DG/YE wires running to the FPDM stock. Did you add the 2nd wire?

Next, the DG/YE wire is the power wire, not signal wire, to the FPDM on an '03 Cobra. The WH/RD wire is the signal wire telling the FPDM to either increase or decrease fuel. An '01 Cobra should have a PK/BK wire for the power wire instead of a DG/YE wire. All other wires should be the same color between '01s and '03s.


>> 6. Wired dual wires to the fuel pumps just like a 03 Cobra. (Dual positive and negative to send more voltage/amps (Upgrade)).

I'm assuming you mean you added another pair of wires from the FPDM to the top of the hat. Is that correct?


>> 7. I have wired a relay to provide constant battery power to the FPDM, switched by the CCRM to activate the relay. Same as in the dual FPDM set up but only with one FPDM.

Just to make sure, which wire are you sending power from the battery to? Is it the DG/YE wire?


>> 9. Data logging I get 100% duty cycle, pumps maxed out. The voltage is 12.9 or lower. This is at idle or driving it.

Now, we are getting somewhere. Fuel pump duty cycle should never be at 100%, even at WOT. For whatever reason, your pumps are being commanded to run at 100%. This could be for a number of reasons, incorrectly setup tune, fuel system unable to maintain proper pressure which is normally a delta pressure of 39psi (ie leak or 1 or more bad pumps), etc. I still have a couple questions about how the pumps are mounted in the hat and how things are wired, but I don't think your problem is directly related to the FPDM. Something is making the FPDM work harder than it should.

And 12.9V is not normal when idling or cruising. It should be closer to 13.5-13.8.


>> 10. Line 9 is why I did line 7. I have 12.5 - 13.7 now coming from the battery to the FPDM depending on state of the alternator.

You mentioned previously that voltage was 12.9 when idling and cruising. Under what condition does the voltage change to 12.5-13.7?


>> 11. Alternator voltage is reading 13.7 down to 12.5 at the battery, Should the voltage be reading higher, say around 13.9 constant? I was going to get a new alternator but the auto parts store has the 110 amp, should I be looking at getting a 130 amp? Which one it the original amps, 110 or 130?

So a reading straight from the alternator is 13.7v, while a test at the battery itself is 12.5? Or is it 13.7 when the car is running and 12.5 when it's not?

No, don't get an auto parts store alternator. They have the wrong listing. You do not want a 110A alternator. IMO, pick either a stock Ford unit from a dealer or a Start-n-charge alternator.


>> Could I have one bad fuel pump? I know that when I turn the key on I hear the CCRM click but not the pumps, and fuel pressure is not showing on the electrical gauge I have installed. I turn the key on and off a couple of times and then try to start it, the car will start up and run. I have about 20-25 PSI fuel pressure while it is running. After it has been running for about 5 min the FPDM with heat up and start to go into thermal overload. This shuts the pumps off and on, I can see the pressure drop and rise when it does this.

You should be able to hear the pumps prime the lines and bring up fuel pressure when you first turn the key.

Without some questions answered, I'm leaning towards a leak from the hoses in the tank. A leak could cause your fuel system to not develop proper fuel pressure. That in turn would make your ECU command more fuel in an attempt to bring up fuel pressure. When at 100%, the pumps can't give anymore. Run at 100% long enough, and the FPDM overheats.


>> So the only problems now are why does the FPDM go into thermal overload, weak fuel pressure and do I have a bad pump or pumps?

The problem is not why your FPDM is going into thermal shutdown. Your FPDM is going into thermal shutdown because it is being commanded to run maxed out. Under normal conditions, duty cycle is about 30% at idle. Your problem is why are you running 100% duty cycle and only 20-25psi of fuel pressure.

It's possible you have 1 or more bad pumps, but as I mentioned earlier, it could also be an internal leak in the tank. Are the pumps new? Used? If used, any idea how old they are? Were they subject to a high HP application before you got them? Was a BAP used on the, for a long time?

 

[03 Indy Cobra]

Op, With all the info you gave in post #9 I am going to say Black 306 has your fuel problem covered. I also learned that 99-04 mustangs all have the same FPDM. This site rocks

 

[Coderedsaleen]

Here are answers to your questions:

>> 4. Changed fuel tank w/pumps to 03 Cobra.

Q. Is it a stock Cobra setup? Meaning, stock hat, stock pumps, PPRV in place? Or have you done any modifications to it?

A. The tank and pumps came with the engine. It has the stock hat, but not sure about the internals. Did not look at it before I installed it. :bash:


>> 5. Wired FPDM the same as it would be on a 03 Cobra (Dual DG/YW wires from the CCRM for the FPDM signal wire).

Q. Couple things here. First, a Cobra does not have dual DG/YE wires running to the FPDM stock. Did you add the 2nd wire?

Next, the DG/YE wire is the power wire, not signal wire, to the FPDM on an '03 Cobra. The WH/RD wire is the signal wire telling the FPDM to either increase or decrease fuel. An '01 Cobra should have a PK/BK wire for the power wire instead of a DG/YE wire. All other wires should be the same color between '01s and '03s.

A. Yes, the Cobra wiring harness does have dual DG/YW wires running to the FPDM. I stripped it from the 03 harness and installed it. You are right about the DG/YW wire as being the power wire, I miss quoted it. :bash: I have the FPDM wired the way a 03 Cobra is by the Ford wiring diagram.


>> 6. Wired dual wires to the fuel pumps just like a 03 Cobra. (Dual positive and negative to send more voltage/amps (Upgrade)).

Q. I'm assuming you mean you added another pair of wires from the FPDM to the top of the hat. Is that correct?

A. No, the 03 Cobra also has dual wires that go to the fuel hat also. On this and the DG/YW wires they all start with a single wire from the connector for about 2 - 3 inches then a second wire is spliced into it. You can only see it if you cut in the harness, which I did.


>> 7. I have wired a relay to provide constant battery power to the FPDM, switched by the CCRM to activate the relay. Same as in the dual FPDM set up but only with one FPDM.

Q. Just to make sure, which wire are you sending power from the battery to? Is it the DG/YE wire?

A. Yes, the battery wire feeds into the DG/YW wire that goes into the FPDM.


>> 9. Data logging I get 100% duty cycle, pumps maxed out. The voltage is 12.9 or lower. This is at idle or driving it.

Q. Now, we are getting somewhere. Fuel pump duty cycle should never be at 100%, even at WOT. For whatever reason, your pumps are being commanded to run at 100%. This could be for a number of reasons, incorrectly setup tune, fuel system unable to maintain proper pressure which is normally a delta pressure of 39psi (ie leak or 1 or more bad pumps), etc. I still have a couple questions about how the pumps are mounted in the hat and how things are wired, but I don't think your problem is directly related to the FPDM. Something is making the FPDM work harder than it should.

And 12.9V is not normal when idling or cruising. It should be closer to 13.5-13.8.

A. I took it the dyno and they are the ones who did the data logging. He showed me on the laptop that the pumps were maxed out. Pressure was reading about 29psi. I'm unsure how the pumps are mounted though since I didn't look at them before I installed the tank.
The voltage issue I kind of figured that it should be higher. When the car is first started and running the volts are 13.7 or 8. Then as it runs the voltage slowly drop to around 12.9 or so.


>> 10. Line 9 is why I did line 7. I have 12.5 - 13.7 now coming from the battery to the FPDM depending on state of the alternator.

Q. You mentioned previously that voltage was 12.9 when idling and cruising. Under what condition does the voltage change to 12.5-13.7?

A. When the car is first started and running the volts are 13.7 or 8. Then as it runs the voltage slowly drop to around 12.9 or so. It pretty much hangs around at the voltage.


>> 11. Alternator voltage is reading 13.7 down to 12.5 at the battery, Should the voltage be reading higher, say around 13.9 constant? I was going to get a new alternator but the auto parts store has the 110 amp, should I be looking at getting a 130 amp? Which one it the original amps, 110 or 130?

Q. So a reading straight from the alternator is 13.7v, while a test at the battery itself is 12.5? Or is it 13.7 when the car is running and 12.5 when it's not?
No, don't get an auto parts store alternator. They have the wrong listing. You do not want a 110A alternator. IMO, pick either a stock Ford unit from a dealer or a Start-n-charge alternator.

A. When the car is first started and running the volts are 13.7 or 8. Then as it runs the voltage slowly drop to around 12.9 or so. This is tested from the alternator leads while the car is running. I understand that if the car was running and the volts read 13.7 the alternator is charging, but it reads 12.5 when not running it means that is battery voltage.

If I need to get an alternator I will pick one up from the dealer, hopefully I won't need one.

Q. It's possible you have 1 or more bad pumps, but as I mentioned earlier, it could also be an internal leak in the tank. Are the pumps new? Used? If used, any idea how old they are? Were they subject to a high HP application before you got them? Was a BAP used on the, for a long time?

A. I have no idea on the status of the pumps, I guess I will have to drop the tank and see what I have going on in there. The engine I bought was suppose to be making 500hp. It has the smallest pulley on it, a maf extender, stegmier ported blower and I think that is about it. :shrug:

 

[Coderedsaleen]

Black306 are you still with me? Any response to my last post? Thanks in advance.

 

[Black306]

Nothing new to add. I think you just need to start working on the car to try and find the problem. Personally, I'd start with dropping the tank and inspect the hoses and pumps.

 

[horspla2000]

I could possible be FRP sensor reading incorrectly. It could be reading low, therefore commanding more FP and maxing out the pumps hwen it doesn't need to be. Just a thought. I agree I'd take a look at the pumps and hoses in the tank first. He ruled out the FPDM since 2 units do the exact same thing.

 

[AMB]

Coderedsaleen

What wiring harness are you using in the engine compartment?? AND what wiring harness are you using from the engine compartment to the FPDM??? The 2001 3v FPDM gets its 12v through the Inertia Fuel Switch output (PK/BK) wire, and its (DG/YE) input wire. The 03 Cobra gets its 12v dirrectly from the (DG/YE) wire that DOESN'T get its 12v from the same place. You have to add/change some wires. :read:

 

[Coderedsaleen]

Nothing new to add. I think you just need to start working on the car to try and find the problem. Personally, I'd start with dropping the tank and inspect the hoses and pumps.

Thanks for the help Black306, I will drop the tank and see what is going on in there since I have already experienced the same types of symptoms with both of the FPDM. I have tried another FRPS and that didn't change anything either. My last ditch effort will be in the tank. Thanks for everyones help on this issue of mine. :beer: and :rockon:

 

[03 Indy Cobra]

Dropping the tank is a good start. Good luck I hope you get everything worked out.

 

[Black306]

Curious. Any update?

 

[Coderedsaleen]

Curious. Any update?

Sorry no updates yet... I have not been able to get out in the garage and drop the tank yet. I hope to do it soon. I will keep the thread informed and thanks for asking.