Hard to start when cold, starts fine when warmed up

Hi,

The first thing I would suggest (if the check engine light stays on with the engine running) is to check for diagnostic trouble code. Here is a quick video showing how it's done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner. However, most parts stores will scan it at no charge or lend you a scanner.

Next is the engine coolant temperature sensor. If it is sending a wrong signal to the computer, the fuel mixture may be too lean or too rich to start it. Again, to check that requires a live data scanner. If you have one, check what temp signal the ECT is sending to the computer and make sure it is withing reasons in comparison to ambient temps.

If that checks good, reconfirm fuel pump pressure. It could still be low. I doubt that is the issue, but it can be.

Do these things and let me know what you find. If you have no access to a scanner, let me know that as well.

Take care,
Joe

The scanner I have is an INNOVA (about 3 years old probably equivalent to the 5610 scanner) There are no codes displaying. Working day shift(12hr shifts) will not be able to check with scanner until Monday. One thing it does is give a little smoke, but not like oil smoke. But that is only if I crank it over a good bit. Will do some checks and let you know.

Does the smoke come from the exhaust? What color does it appear to be? And no problem with when you get to it. I'll be here.


Let me know.
Joe

The smoke is light white. By that I mean it is not a heavy white smoke from oil. It disappears in about 2 seconds. The engine runs smooth after about 5 to 10 seconds after it is started but will occasionally increase in rpm about 100 to maybe 150 rpm above idle. When driving I have no hesitation when accelerating and the engine does not shut off when I come to a stop. Only hard starting when it is cold. The plugs have about 8,000 miles on them and I did not have the problem until cold weather hit back in late October to early November. Ran fine up till that point and then all of a sudden hard start. Does not make much sense to me but I am not that smart.

Okay. Chances are it is steam from the exhaust and nothing more. However, the hard cold start can be the temp sensor or low fuel pressure among other things. Since it started when it got colder, I have a feeling it is related to the sensor.

Regardless, let me know.

Joe

Follow up on hard starting when cold. Used code scanner on Live Data prior to starting and after starting. All data in range of normal readings. Temp., voltage, etc. Got me puzzled. Any suggestions. Engine runs smooth once started and restarts easy once it runs a minute or so.

Okay, then we need to confirm fuel pressure and see if it is dropping off and causing the hard start. Here is a link that shows how it is done.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the directions specific to this vehicle. I have a feeling the fuel pressure is low at first when starting and then okay after you get it going. The attached pics correlate with the directions.

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2010 Ford Truck F 150 4WD V8-5.4L Flex Fuel
Fuel System Pressure Test
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Testing and Inspection Component Tests and General Diagnostics Fuel System Pressure Test
FUEL SYSTEM PRESSURE TEST
310-00 Fuel System — General Information 2010 F-150
GENERAL PROCEDURES
Fuel System Pressure Test

Special Tool(s)

pic 1 Fuel Pressure Test Kit

310-D009 (D95L-7211-A) or equivalent

pic 2 Fuel Pressure T-Adapter 3/8"


310-D252 or equivalent
image WARNING: Do not smoke, carry lighted tobacco or have an open flame of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

image WARNING: Before working on or disconnecting any of the fuel tubes or fuel system components, relieve the fuel system pressure to prevent accidental spraying of fuel. Fuel in the fuel system remains under high pressure, even when the engine is not running. Failure to follow this instruction may result in serious personal injury.

image WARNING: Do not carry personal electronic devices such as cell phones, pagers or audio equipment of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

image WARNING: Always disconnect the battery ground cable at the battery when working on an evaporative emission (EVAP) system or fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

image WARNING: When handling fuel, always observe fuel handling precautions and be prepared in the event of fuel spillage. Spilled fuel may be ignited by hot vehicle components or other ignition sources. Failure to follow these instructions may result in serious personal injury.

pic 3

If servicing a 4.6L (3V) engine, remove the Evaporative Emission (EVAP) purge valve bracket bolt and position the bracket aside.

pic 4

If servicing a 5.4L (3V) engine, remove the air intake resonator assembly bolt and loosen the clamp. Rotate the resonator upward until it stops.

pic 5

NOTE: 4.6L (2V) shown, 4.6L (3V) and 5.4L (3V) similar.

Remove the fuel pressure relief valve cap.

pic 6

NOTE: 4.6L (2V) shown, 4.6L (3V) and 5.4L (3V) similar.

Install the Fuel Pressure Test Kit onto the fuel pressure relief valve.

pic 7

NOTE: It may take more than one key cycle to pressurize the fuel system.

Cycle the ignition key to the on position and wait 3 seconds to pressurize the fuel system. Check for leaks before starting the engine.
Test the fuel system pressure to make sure it is within the specified range. For additional information, refer to Specifications in this section.
NOTE: 4.6L (2V) shown, 4.6L (3V) and 5.4L (3V) similar.

NOTE: Open the drain valve slowly to relieve the fuel system pressure. This may drain fuel from the system. Place the fuel in a suitable container.

Upon completion of the fuel system pressure test, open the drain valve on the Fuel Pressure Test Kit and relieve the fuel system pressure.

pic 8

NOTE: 4.6L (2V) shown, 4.6L (3V) and 5.4L (3V) similar.

Install the pressure relief valve cap.
Tighten to 6 Nm (53 lb-in).

pic 9

If servicing a 4.6L (3V) engine, position the EVAP purge valve into place and install the bracket bolt.
Tighten to 10 Nm (89 lb-in).

pic 10

If servicing a 5.4L (3V) engine, rotate the air intake resonator assembly into position and install the bolt.
Tighten to 10 Nm (89 lb-in).

pic 11

6.2L (2V) engine

Release the fuel system pressure. For additional information, refer to Fuel System Pressure Release in this section.
Disconnect the fuel tube quick connect coupling. For additional information, refer to Quick Connect Coupling in this section.
Install the Fuel Pressure T-Adapter 3/8" and Fuel Pressure Test Kit in line between the fuel supply line and fuel rail.

pic 12

NOTE: The Fuel Pump Control Module (FPCM) electrical connector was disconnected during the fuel system pressure release and must be reconnected to complete the Fuel System Pressure Test.

Connect the Fuel Pump Control Module (FPCM) electrical connector.
Connect the battery ground cable. For additional information, refer to Section 414-01 .
NOTE: It may take more than one key cycle to pressurize the fuel system.

Cycle the ignition key and wait 3 seconds to pressurize the fuel system. Check for leaks before starting the engine.
Test the fuel system pressure to make sure it is within the specified range. For additional information, refer to Specifications in this section.
NOTE: Open the drain valve slowly to relieve the fuel system pressure. This may drain fuel from the system. Place the fuel in a suitable container.

Upon completion of the fuel system pressure test, open the drain valve on the Fuel Pressure Test Kit and relieve the fuel system pressure.
All engines

NOTE: It may take more than one key cycle to pressurize the fuel system.

Cycle the ignition key to the ON position and wait 3 seconds to pressurize the fuel system. Check for leaks before starting the engine.

_________________________________

Pay attention to fuel pressure drop off. That is when you turn the key off. I would recommend doing this when the engine is cold and will have the conditions indicated.

Let me know if this helps or if you have other questions.

Joe

Checked the fuel pressure. When ignition switch first turned on it is at about 15 psi. Cycle 3 times it is 50+/- a couple. Start truck fuel pressure is 50 PSI +/- a couple. It idles good and runs good. Gas mileage has not been affected. After engine is turned off with the pressure gauge hooked up it will very slowly drop from about 50 psi to about 45psi. Let it set for a couple of hours and it still starts right up. Overnight is a different story. I would pull my hair out but I am bald so I cannot do that. Any suggestions.I have not changed the temp switch on the cylinder head yet or the Mass Air Flow Sensor. Any other suggestions.

The 15 psi on the first turn is low. Do me a favor. Cycle the key from off to on (run position engine off) three times. On the fourth time, see if it starts easily. Pressure with the engine running should be between 55 and 60 psi.

See if cycling the switch helps it cold start.

Let me know.
Joe

Performed test as recommended. Hesitated a little but started. Why would I have low pressure at first. New fuel pump, new throttle body and fuel pump pressure switch. Could I have an injector leaking off? That might account for the low pressure at first and the light white smoke I had mentioned before. Do not think it is water vapor. Once started it runs fine and starts fine until the next day or if it sits for 8 or more hours. Still has me somewhat puzzled.

Hi,

Something is allowing pressure to bleed off. It could be a leak or an injector. Now I'm basing that on the fact that you just replaced the pump and so on. I do have a concern regarding what you said about the white smoke that doesn't appear to be water vapor. White smoke is usually associated with coolant entering the combustion chamber as a result of a head gasket issue or other internal issue. Can you record upload when you see the smoke so I can see what is happening?

Now, since it did start with cycling the switch, we really need to confirm that at a cold start, pressure is low. I recommend following the directions for testing fuel pressure I listed first. You may just have a weak pump.

Also, here is a link that explains how to check for a bad head gasket. I don't think this is the issue, but in one way it could be. When the engine is cold (after sitting) steel contracts. That can cause lower compression or allow a gasket to leak. After it warms up, the steel will expand, possible sealing off any issues. Truthfully, that is really a long shot. I only mention it because you said about the white smoke.

https://www.2carpros.com/articles/head-gasket-blown-test

Check to make sure the coolant level isn't down and let me know what you find.

Take care,
Joe

Have checked the coolant level. It is fine. Have not had to add much more than a quart since I have owned the truck. Almost 10 years. The light white smoke I am attributing to unburned fuel when I let it just crank and crank before it finally starts. When I performed the test by doing the on/off/on/off/on/off and then starting there was no smoke. Hope that makes sense. The test was performed when it was about 25 degrees so it was plenty cold enough. Low fuel pressure on initial start up without cycling the ignition is making more sense. More of a pain in the wazoo than anything. Truck runs fine. Does have an idle problem once in a while where it seems like the rpm goes from about 700rpm to about 1500rpm but right back down. Will do that a couple of times then settle out. Any other ideas. I am all ears.

The idle could be a result of pressure as well. However, there is what is called and idle air control valve (IAC) that can cause that to happen. The IAC is located on the throttle body and maintains the engine idle speed. Basically, it allows air to enter the engine when the throttle plate is fully closed.

Just for the heck of it, try cycling the key for a couple days to see if it consistently allows the vehicle to start easier. If it does, then perform the pressure test. The truck has a returnless system, so there could even be an issue with the fuel line pressure sensor on the rail.

Like you said, a pain in the wazoo. LOL And the worse news is, they just keep getting more and more complex. Ugh!

Take care and let me know what you find.

Joe

Did as suggested. The fuel pressure sensor has already been changed. Cycling the key helped some. Even after cycling 4 times it did not start real easy. When we checked the fuel pressure when it was turned on it went to 15 psi and picked up some each time. When it starts in less than 5 seconds it smooths out and if I turn it off it restarts very easily. So I figure I do have a fuel pressure problem. New pump, pressure switch and throttle body. We have had some warm days recently and it makes no difference on the ambient temp. Problem is I retire in 19 days and my income drops a lot so I have to get it fixed soon.

Retirement? Congrats!!!

Okay, I need you to check a specific fuse in the battery junction box. It is fuse 27. Do me a favor, pull it and inspect the fuse as well as the socket it goes to. I remembered reading about an issue with them overheating and causing hard start or no start conditions. See pics 1 and 2.


Let me know.

Joe

Already checked that. Fuse is fine and no problem with the socket.

If you have 12v at the socket, then either the pump is bad or something is causing a restriction.

At this point, I would check to see if pressure is good right at the module. If it isn't, the pump has a problem. If it is, then there is a restriction at some point.

Joe

New pump and from what I can find all voltages are good. As far as restriction when out on the road when I put the hammer down hold on to your wig. If there were a restriction it would probably do a nose dive. Not the case. Runs too good. Problem is only when first started after not running for about 12 hours more or less. If there were a restriction it would probably happen every time I started the engine and not just when it was cold and most certainly when I tried to pass someone. I would pull my hair out but since I do not have any I will just scratch my ____ and go from there.

Take a look through this info and let me know your thoughts. In most cases, the injector pump either works or it doesn't. I guess it's possible that we have a new type of issue. However, you are checking fuel pressure before this component. Once the engine starts, the fuel injection pump increases pressure. That is why I don't feel it is related.

_______________________________

2010 Ford Truck F 150 4WD V8-5.4L Flex Fuel
High Pressure Fuel System
Vehicle Powertrain Management Computers and Control Systems Testing and Inspection Diagnostic Trouble Code Tests and Associated Procedures Powertrain Control/Emissions Diagnosis (PC/ED) Section 1: Description and Operation High Pressure Fuel System
HIGH PRESSURE FUEL SYSTEM
2010 PCED Gasoline Engines
SECTION 1: Description and Operation
High Pressure Fuel System
Overview
The high pressure fuel system receives low pressure fuel from the fuel pump module and delivers fuel at high pressure to the direct injection fuel injectors.

The high pressure fuel system consists of the fuel injection pump, the fuel volume regulator, the fuel rail pressure (FRP) sensor, the fuel supply line, the fuel rail, and the fuel injectors. For additional information on the fuel system components, refer to Engine Control Components in this section. Operation of the system is as follows:

1) The fuel injection pump receives fuel from the fuel pump module, increases the fuel pressure from approximately 448 kPa (65 psi) to a PCM determined pressure up to as high as 15 MPa (2175 psi), and delivers it to the fuel rails.

2) The fuel volume regulator controls the volume of low pressure fuel that enters the inlet check valve and the pump piston inside the fuel injection pump. The PCM regulates fuel pressure by controlling the timing of the fuel volume regulator solenoid.

3) High pressure fuel exits the fuel injection pump and is delivered to the fuel rails through the fuel supply line.

4) The fuel rails distribute and channel high pressure fuel to the fuel injectors.

5) The FRP sensor provides a feedback signal to indicate the fuel rail pressure so the PCM can command the correct injector timing and pulse width for proper fuel delivery at all speed and load conditions.

6) The fuel injectors meter fuel flow to the engine. A given cylinder fuel injector can deliver single or multiple injections for each cylinder event. The amount of fuel is controlled by the length of time the fuel injectors are held open.

pic 1

High Pressure Fuel System

___________________________________

The other thing is the fuel pump control module. It may not be working properly, but then you wouldn't have 12v right away to the pump.

Sorry for taking so long in replying. The truck is starting easier since the weather is warmer. It just might be a temperature problem like you mentioned. Where is the temperature relay located?

Hi,

Glad to heat it's starting easier. As far s the temperature sensor, it is under the intake manifold. Take a look at the attached picture. It shows the location.

Please let me know if I can help. I hope you are well in these crazy times.

Take care,

Joe

Sorry, been quite a while since I contacted you. Lot has happened. Did finally get around to replacing the "coolant temperature" sensor. Seems to have corrected the problem. Will not know for sure until winter gets closer. Going to need quite a bit of body work.

Hi,

Glad to hear from you. Hopefully that will take care of the issue. Please feel free to come back anytime in the future if you need help or have questions.

As far as body work, I hope you weren't in an accident.

Take care and if the problem returns in the winter, let me know.

Joe

Well I am back. Cold weather is upon us and the hard start problem is coming back. So far I have replaced the following: Fuel pump, fuel pressure switch, complete throttle body and engine coolant temp sensor. No starting problems in the warmer weather. First cold weather then the problem came back. Truck listed above is a XLT Lariat.

Hi,

You have replaced nearly everything. Does it start normally when the engine is already warm? If so, we may have to check compression to see if it is low which can cause a hard start cold.

https://www.2carpros.com/articles/how-to-test-engine-compression

Let me know.
Joe

The problem only occurs in cold weather. Once started the engine will restart easily. I have less than 132,000 miles on the truck. I pull my car hauler and camper with no problem. So I have plenty of power. If I had a loss of compression I would be able to tell. One thing it does do is when at idle the engine will go from 750 RPM's to about 1,500 RPM's then back down. Does it multiple times, even when the engine is warmed up.

As far as the idle, that is usually the result of a faulty idle air control valve. That is what allows metered air to enter the engine when the throttle plate is closed. However, your description could also indicate an issue with the mass air flow sensor.

Let's do this: Remove the MAF and see if it appears dirty. Try cleaning it with MAF cleaner that you can get at a parts store.

Here is a link that shows how it's done:

https://www.2carpros.com/articles/mass-air-flow-service

The attached pic shows the location.

Let me know.

Joe

Since there is 3 hours time difference I will do this tomorrow. Will clean, reinstall and let you know tomorrow.

Hi,

It sounds like a plan. I'm in PA, so I'm not sure where you are located. LOL

Regardless, take care and let me know.

Joe

Clarification, when I looked at the time stamp it shows 3 hours difference. I am in southern Ohio so our time is the same. I replaced the MAF's module. Seems to be idling fine but was still hard to start. Might be because I tried to start it right after instillation. Cannot remember where I read it but one article said if replacing the MAF's that the computer would have to readjust (recalibrate) itself and I did not give it time to do so. Supposed to be cooler overnight so will test it again on Friday morning. After warming up it had restarted with no problems and the idling seemed smother but the jury is still out on that also. Time will tell. Could I possibly have a "Crankshaft Position Sensor" that is breaking down in cold weather? As I mentioned it starts fine when the engine is warm and in warmer weather.

Hi,

Our main office is in CA. LOL I'm in Pittsburgh. My brother went to school in a town called Ada (near Lima I believe). I know the school is called Ohio Northern, but I swear I remember driving south once off the Ohio turnpike. LOL Is that near you?

Anyway, I'm not saying it couldn't be a crank sensor, but most times a crankshaft position sensor is affected by heat when they fail. Take a look through this link. It explains the most common symptoms of a bad sensor.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

Let me know if that helps. Also, let me know if it starts normally tomorrow.

Take care,
Joe

Live not far from Portsmouth. As far as the crank sensor I was grasping at straws. I replaced the MAF sensor yesterday. Outside temperature at 9:30 am today 11/13/2020 shows 40 degrees. Truck cranked between 8-10 seconds before it started. When the weather is colder it cranks longer. About ready to take it to the Ford garage. Know it will be expensive but not sure what else to do.

I wish I was there to experience it. I know you replaced the temp sensor. Are you able to confirm that it is sending the correct signal when cold?

Let me know.
Joe

Well it turns out the MAF sensor did not change things a bit. Still hard to start when cold.. The engine RPM still surges while at idle. Not sure what else to do. As far as the temperature sensor (coolant temperature sensor) it was replaced but the weather started warming up and the truck had no issues. Now that it has started cooling down. Same old problems. To say I am frustrated would be putting it mildly.

Are you still getting 15psi at the first startup? I remember that the pressure was slow to increase.

Joe

Fuel pressure is a good bit higher than 15PSI. Still having the fluctuation of the engine rpm at idle. Beginning to think it is a computer problem. I have tried so many different things. I have scratched my head, my backside and several spots I will not mention trying to figure out what is wrong with the truck . Next step is the Ford garage.

LOL Good one. I know the fuel pressure needs to be within the manufacturer's spec as soon as you start it. If that isn't happening, that is an issue.

Joe

Well, it has been a long time and a lot of money spent but finally got the darn thing fixed. As a reminder: hard to start in cold weather. When warm weather came around no problem. Changed fuel pump, pressure switch for fuel pump, throttle body and coolant head temperature sensor. Even put a new MAF sensor on it. All to no avail. Took the truck to a specialty shop. $1,127.00 later it is fixed. In the years I had the truck I put a cold air induction system on it. (went from about a 4" to about a 6" air intake. Also put a little "black box" that was supposed to retune the computer. Well the first mechanic had replaced the fuel pump and removed the black box. Still had the initial problem of hard starting. Turns out that since I had taken the factory air intake system off and put the other on the MAF sensor was not seeing the complete air flow. When the guy took off the black box(giving funky reading on scanner) the truck computer thought I was using E-85 all the time. Cold weather it caused it to flood out. When the specialty shop run the diagnostics on it showed a setting for flex fuel due to the intake that I had put on. He put a stock air system back on it and updated and reset the computer. Problem solved. All because I was getting fancy with some newer stuff. Have learned to leave well enough alone. With all the garage bills it cost almost $2,400.00. Good thing is that it runs great now. One other thing I learned. On some F-150 in the 2010 year range Ford had a problem with the flex fuel system. They also had a small problem with what turned out to be a vacuum leak. Back of block and the only way to find it was to spray carburetor cleaner which cause the RPMs to change. Bear to fix but still simple. Hope my bad experience helps out someone else.

Hi,

First, thank you for the update. I know it will help others. I honestly didn't know we weren't dealing with factory parts (cold air intake). Regardless, I'm glad to hear it is running good again. Please feel free to come back anytime in the future if you have questions.

Take care,

Joe

My fault for not putting that into the notes that I had sent. The truck had run great for years. I think the problem got compounded when the original mechanic changed the fuel pump and took off the black box. It may have cured the original problem but allowed another problem to develop that showed the same symptoms. The black box corrected the original air flow setting. May have had a fuel pump going bad. When fuel pump changed and the black box removed the computer saw it as E-85. Warm weather no problem but in cold weather, that was a different story. Just glad it is fixed.