Engine Start after Flat Towing with Key on

[CapnDean]

I tow my 2012 Edge Limited FWD 3.5 V6, behind my RV 4 wheels down (AKA Dinghy Towing). When the car was outfitted to be towed, I had a charging kit installed to keep the battery charged during towing. The car tows flawlessly.  Here's the issue:  After towing for 3 or 4 hours, I start the engine to run the car for 5 minutes as the owners manual dictates. When I turn the key...the car does not start immediately (like it usually does) the starter has to grind for a much longer time to get the engine fired off.  Even if you let off the key...the starter stays engaged until the engine fires.  I can also smell the strong smell of gasoline when I get out of the car.  Its as if the engine has been flooded while I am towing and it is having to clear the fuel in order to start.

 

If I stop the RV, go to the car and put it in park & turn off the key - and wait 5 minutes before starting....It starts right up and does not exhibit this behavior (Extended grind to start).

 

I am 100% sure that I am following the proper pre-tow set up - running the engine ahead of time, shifting through the gears properly before leaving it in neutral etc.   I am also 100% sure that the ignition key is left in position 2 (1 is OFF, 2 is ACC on, 3 is RUN, & 4 is starter engage.   The car does not count miles on the odometer when I tow it with the key in position 2.  

 

The starting concern is as if the fuel pump is running continuously while I tow, as a result it is flooding the engine.  I am not exactly sure if that is the issue, but that's what it seems like.   

To the experts who know more than me, I submit the questions.....  WHAT CAN I DO to prevent this other than disconnecting the battery altogether?   Does anyone know what fuse I can pull to kill the power to the car without killing my radio presets and all that jazz?  Can I just kill say the fuel pump and a few other circuits?   My battery isn't draining because the charge leg from the RV keeps that in check.    Anybody know the answers here?

[omar302]

Did this start to happen only recently? I don't recall reading of a similar issue, but some long cranking times and smell of fuel are usually signs of a bad EVAP purge valve, this would happen after refueling, it might be it. 

 

 

[WWWPerfA_ZN0W]

Do you notice any fuel level changes between startups?  Could it be the brake system is starting up the PCM?

 

Also could be a fault with the transmission range sensor, even stray voltage maybe, that causes the vehicle to think it is in a particular gear when in reality it is not.

 

From the 2014 towing guide:

(3) All-wheel-drive/Intelligent 4WD vehicles cannot be towed on a dolly.
(4) Maximum speed with automatic transmission is 65 mph.
(5) Start the engine and allow it to run for five (5) minutes at the beginning of each day and every six (6) hours
thereafter.

 

Emergency towing
In case of a roadside emergency with a disabled vehicle (without access
to wheel dollies, car hauling trailer, or flatbed transport vehicle) your
vehicle (regardless of transmission powertrain configuration) can be flat
towed (all wheels on the ground) under the following conditions:
• Vehicle is facing forward so that it is being towed in a forward
direction.
• Place the transmission in N (Neutral). Refer to Brake-shift interlock
in the Driving chapter for specific instructions if you cannot move the
gear shift lever into N (Neutral).
• Maximum speed is not to exceed 35 mph (56 km/h).
• Maximum distance is 50 miles (80 km).

Edited January 27, 2020 by WWWPerfA_ZN0W

[CapnDean]

This started happening when I started Towing my 2012 Edge.  So, yes it started recently, but the precedent event is flat towing the car.    I am almost 100% that the problem stems from leaving the key "on" (actually in the ACC mode).  As I described, there are actually four positions of the key switch.  Position 1 is off and the steering wheel is locked.  The car has to be in position 1 in order to remove the key from the ignition.

Position 2, I call it ACC for accessory.  Position 3 which is "run" this is the position that the key is in when you let off the starter, and of course position 4 is a momentary position designed to engage the starter.

 

In order to ensure that I am in position 2, I shift the car into neutral before  turning the engine off.  The gear shift will not permit me to turn the key into position 1 unless the car is in park.  

 

It is my belief that the fuel pump is running anytime the key is in position 2.  Of course my fuel gage is not showing loss of fuel because I am towing the car with the engine off.   I think it's just keeping the fuel pressure at the PSI the car needs to run.  As a result, when restarting the car....it takes a long grind to expel the excess fuel.   

 

Is there a fuel pump fuse that I can pull before I tow the car behind my RV to confirm this?   Anybody know where the fuel pump fuse is?

[dajo2012]

We towed a 2012 Flex for several years and miles.  To tow it I never used a battery charge line and never had battery charge issue except the one time I left it in acc position. To tow the Flex the procedure is the same as the Edge.  While towing turned the key counterclockwise just past the acc position as far as it would go. Since ignition was locked out by shifter position and would not turn any further. No problem ever with key moving while towing. I learned about doing this  from other owners on the internet. Now have an ST and will be towing it.

[WWWPerfA_ZN0W]

Fuse 65 in the Battery Junction Box / underhood fuse box.

[CapnDean]

On 1/30/2020 at 1:56 AM, WWWPerfA_ZN0W said:

Fuse 65 in the Battery Junction Box / underhood fuse box.

WWWPerf YOU SIR are a STEELY eyed missle man!  Thank you for your help!  You hit it right on the head and hard!  Pulled 65 and the problem has been resolved!