P-0191 Code and Random frequent Stall/no start

[2006LIMITED]

So, 2006 Expedition Limited, 5.4L Truck has progressively gotten worse at starting, I know this is a very common issues with these trucks, just need further guidance.

Here's what I have changed to date, (going back the past 6 months)

Fuel Rail Pressure Sensor
Fuel Pump Driver Module (also checked voltage going into the module) Power coming in is approx. 4 V should be 12V.
Fuel Pump has been changed out 3 diff times (after ford garage diagnosed a bad fuel pump twice) Installing Motorcraft pump on Monday, the last two were aftermarket.
Fuel Filter.
Throttle Body Motor and TPS (After ford diagnosed TB being cause of stalling)

After much research and frustration, I see a lot of owners advising to change out the R-303 relay (which as you know is located in the Fuse Box and is not easy as just changing the relay) I am thinking this relay is on its way out or possibly the inertia switch is bad. I haven't had a chance to check voltage to the inertia switch yet as the rear c pillar panel has to come completely out to gain access to the actual harness.

With the scan tool hooked up I am getting good fuel rail pressure 38 psi with the key on and if the truck does start on occasion when the truck stalls that fuel pressure reading drops to zero or hovers around 2- 5psi. The engine dies and it usually takes about 4 attempts to get the engine to fire and stay running. I have had the truck to the dealer 3 times to get them to put there computer on it and they have done nothing more than tell me what i am already aware of. They have not troubleshot the issue, or have chased any wiring problems that may exist.

To this point Im leaning on a possible Bad or going bad relay, My question is why is the FPDM only getting 4 volts? and why is the stalling occurring randomly? Usually the first start of the day it cranks right up, but if you drive it 10-15 min park it somewhere and come back out to start the truck it will not Start, and takes multiple times to get it to run .

Starting to get un-nerving and tired of the consistent stalling problems. I need this fixed now and with winter coming here in ohio I want to get this fixed soon.

Any assistance or experiences any of you may have had would be welcomed.

Thanks,


Todd

 

[metaldrgn]

Sounds like a relay. Could be wiring too. If you get 2-5 PSI and can't get more than that, you can try and eliminate the relay by pulling out the relay and connecting pins 87 and 30 I believe (can get specifics tomorrow). If that works you could swap the relay with another similar relay like for the horn and see if that fixes it. If it doesn't maybe your PCM is bad or the wiring from the PCM through the relay to ground is faulty. You should have a 3 sec prime with the key in the on position so you could check for voltage there and check your ground on the other end.

Is the fuel pump returnless?

 

[metaldrgn]

sorry forgot about this post. It is 87 and 30. DON'T do this if it's returnless because the PCM regulates the voltage. When you pull the relay you will see those numbers. just use a paperclip, safety wire, or something like that. Here's a diagram of how those relays work. If the coil is shorting or open it will not switch the leverl arm from 87a to 87. Sometimes it can be intermittent too and just chatter.

Make sure the key is in the off position. If you have a ohmmeter, check pin 87 to the negative terminal on your battery and report your values (doesn't matter what kind of pump you have for this check). Check pin 30 to the terminal too. That should be the one that goes to your PCM and should be a high reading. Post that value as well.

 

[2006LIMITED]

Finally got it figured out, The relay to the Fuel Pump, FPDM, and Fuel Rail Pressure sensor is R303 and is internal to the Fuse Panel. (relay is not replaceable on its own) When I removed the Fuse panel to inspect the relay, we found it on its way out, Relay had burn marks on one side causing the intermittent start/stalling issues. So I ordered a new fuse Panel from Tasca Ford. It arrived on Thursday of last week. Ford completely changed the layout of the new fuse panels (maybe they are aware of the frequent failing) After installing the new Fuse box the truck has had ZERO issues with starting or stalling. A shame it took me six months of my own research to get this resolved and ford had the truck three different times and couldnt figure it out. The misdiagnosed it each time. For those with the same issues, save your self time and money and check the fuse box first for the internally wired Relay, this is what went bad on ours. Good thing now is that the entire fuel system on our truck has new parts so we should be good for years to come.

Thanks for the replies. Just wanted to share with what worked and fixed the problem in my case.


Todd

 

[ExpeditionAndy]

manofmanyfords had a similar problem and came up with the same solution. Here is his post with a link that clearly shows how to make the repair.

http://www.expeditionforum.com/f41/...but-doesnt-start-21903/index3.html#post175765

 

[bedrck46]

This is a good post for the Ford service guy that always says take it to the dealer. From your post the dealer had it 3 times and couldn't find the problem. Makes you wonder why so many on this site asks for the help of others. You should go back to the dealer and let them know what was wrong and what it took to fix it and if there were any charges from them that you should get a refund for them not finding the problem and replacing parts that may have not been needed to be replaced

 

[metaldrgn]

Exactly! That's why I do all my own work.

 

[2006LIMITED]

This is a good post for the Ford service guy that always says take it to the dealer. From your post the dealer had it 3 times and couldn't find the problem. Makes you wonder why so many on this site asks for the help of others. You should go back to the dealer and let them know what was wrong and what it took to fix it and if there were any charges from them that you should get a refund for them not finding the problem and replacing parts that may have not been needed to be replaced

Exactly what I plan on doing tomorrow!!! Inexperienced Mechanics telling average people what needs to be fixed. If they had, had their way I would have had 1400 dollars in them changing the fuel pump. Which by the way I did 3 diff. times I can do it in my sleep now in under an hour. I am an aircraft mechanic by trade, and nothing i did was that difficult the average mechanic couldn't have done. It is forums like this and people such as you that offer the guidance and know how to help eliminate ford techs from stealing from people who have the willingness to try and fix it themselves. Thanks a Million, Hopefully this post will help someone in the future. When i get the chance I will post pictures of the failing relay,


Thanks again,


Todd

 

[Trckmagik]

Thanks for the info

 

[bedrck46]

Todd Kindly update us as to how you make out at the dealership