2010 Edge cranks but wont start (but always starts)

[ldogg0123]

I've lurked around this forum for a while looking for various topics and have had some pretty good luck. So I'm here today to seek out this forums infinite wisdom on an issue I can't for the life of me figure out.

 

My wife's 2010 Edge (155,000) mi intermittently cranks but will not start up on the first attempt. This issue has not occurred in the mornings on a cold start, but randomly occurs throughout the day at least once. After not starting on the first attempt, if I turn the key off and try to start again it fires right up every time. Should note here that turning the key to the on position and waiting for the fuel system to prime has no affect on this issue. I can hear the fuel pump prime every time I turn the key to the on position. I've replaced the evap purge valve, crank position sensor, spark plugs, ran fuel system cleaner, checked and swapped relays and fuses around, and now I'm at a loss. If I start and stop the vehicle a few times I can usually get this issue every 4th or 5th time. 

 

Also side question: The vehicle doesn't have remote start but occasionally if you randomly hit the buttons on her key (in some order that I can't figure out), the car starts. I've walked out the store to find the car running with no keys in it. You can even put it in reverse and drive off without putting the key in. Anyone else ever come across ghost starts like this? 

[enigma-2]

Almost sounds like a defective ignition switch. 

[WWWPerfA_ZN0W]

could be an issue with the battery, starter, or fuel pump.

 

check battery voltage and CCAs with a digital tester.

if you only hear click-click-click of the starter, or if the starter keeps going after engine fires up, look at how many amps it is drawing and if there is excessive resistance in the wiring.

check fuel pressure.

 

i am ruling out the PATS system for now, but fobs/transponders could have some involvement if the battery or the electronics are failing.

[ldogg0123]

Starter seems to be working fine, once the engine starts it doesn't keep going. Everything sounds normal when you try to start it. It just keeps cranking hard like its trying to start until the key is turned off. Then it starts right up when you turn the key again. I haven't checked fuel pressure yet, that's likely next on my to do list. After it starts up everything runs normal. No loss of power going up hill or when hammering down on the gas, doesn't idle rough etc. It just randomly doesn't like to start on the first try, then it cranks right up and runs great. 

[WWWPerfA_ZN0W]

the start sequence does not require you to hold the key in the start position, just needs you initiate it. once you release the key, the starter should keep trying to crank for 10 seconds automatically, then stop, under NORMAL conditions.

 

i would also check the crank sensor for a good signal. i know you replaced it and other parts, but did you use OEM or aftermarket? not to put too fine a point on it, but in many things electronic, especially in the powertrain, aftermarket has been iffy.

 

=============

Starting System

The starting system consists of the following:

• Starter motor
• Starter motor relay
• Transmission Range (TR) sensor
• Battery
• Ignition switch
• PCM
• Start diode

When the starter solenoid is energized, a magnetic field is created in the starter solenoid windings. The iron plunger core is drawn into the starter solenoid coil, and a drive lever and pin connected to the starter drive engages the drive pinion gear to the flexplate ring gear. When the plunger is pulled all the way in, its contact disc closes the circuit between the battery and the motor feed terminals. This sends current to the motor, and the drive pinion gear cranks the flexplate to start the engine. When current flows to the starter motor, the starter solenoid pull-in coil is bypassed, and the hold-in coil keeps the drive pinion gear engaged with the flexplate.

 

An overrunning clutch in the starter drive protects the starter motor from excessive speeds during the brief period before the driver releases the ignition switch from the START position as the engine starts.

 

The starting system uses a TR sensor located in the transmission. The TR sensor prevents operation of the starter motor unless NEUTRAL or PARK is selected. The vehicle has One-Touch Integrated Start (OTIS), a computer-assisted cranking system. This feature assists in starting the engine. If the ignition key is turned to the START position and released when the engine begins cranking, the engine may continue cranking for up to 10 seconds or until the vehicle starts.

 

One-Touch Integrated Start (OTIS)

Once the ignition is turned to the START position and the vehicle is in NEUTRAL or PARK, the PCM reads starter motor request from the ignition switch and gains control of the starter engagement. The customer is no longer in the loop after the initial crank request, the customer may release the key to the RUN/START position. The PCM will disengage the starter motor based on the following events:

• The engine is started (rpm threshold)
• A set time has been exceeded (calibrated)
• The ignition key has been turned to the OFF position

[ldogg0123]

5 hours ago, WWWPerfA_ZN0W said:

the start sequence does not require you to hold the key in the start position, just needs you initiate it. 

 

 

That's correct. I should note I don't hold the key in start position, I can typically tell when it wont start, so I don't typically let it go the full ten seconds. I'll typically turn the key off after about 7. My wife will let it go until it stops cranking on its own. The crankshaft position sensor I replaced was OEM. As big as a pain as that was to change, due to its location, my limited workspace, and the lost socket that I had to fish out with a borescope, I'm going to trust its working correctly strictly for the sake of not having to repeat that process again. 

[ldogg0123]

I forgot to mention in my previous posts that the vehicle has never thrown any codes when this occurs or otherwise. 

[Dome91]

On 3/30/2021 at 6:24 AM, ldogg0123 said:

I forgot to mention in my previous posts that the vehicle has never thrown any codes when this occurs or otherwise. 

 

Hi, did you solve the problem?