[Solved] 2007 Dodge Ram 1500 - Long Cranking Period

Affiliate Disclosure: As an Amazon Associate, we may earn commissions from qualifying purchases from Amazon.com.

Here is a list of tools I use every day at the shop. Let me know if you use them too in the comments!

---

If you just want to know what the fix is for this vehicle, click here!

---

Customer Complaint:

This 2007 Dodge Ram 1500 with a 5.7 liter engine came to the shop with a complaint of a long cranking period. When the truck has been sitting for a long length of time it would take a while for it to start.

First Thoughts:

Many issues can cause a long cranking period, but a common problem is a fuel pump that has an issue. Fuel pumps can become “weak” over time or not hold pressure after the key is turned on.

---

Sometimes bad fuel injectors can cause a vehicle to not start. Check out this case study on a GMC Sierra that had bad fuel injectors! Click here.

---

Diagnostics:

When trying to start this 2007 Ram 1500, it did exhibit a long cranking period. It took about 10 seconds of cranking to actually get it to start. It drove very well and did not have a check engine light.

I have worked on many vehicles with this same issue and in most cases, they have the same problem.

Lack of fuel pressure. When cranking, it sounded like it was trying to start but didn’t have any fuel.

One of your most important tools is your ears. On some vehicles, the sounds that they make are similar to each other and can provide excellent diagnostic information. For example, in most applications, vehicles that are running out of fuel sound similar.

Before I hooked up a fuel pressure gauge to confirm my thoughts, I wanted to try something.

Instead of trying to start the truck on the first key cycle, I wanted to cycle the key several times to see if I could build up the fuel pressure.

On this fuel system, and many other fuel systems, the fuel pump primes the system to the correct fuel pressure when the key is turned on.

In some cases, I’ve seen fuel pumps “lose” their prime and the key would have to be cycled over and over again to build the fuel pressure up.

First Test:

After cycling the key four times, the truck started right up.

This test gave me a clue that the fuel pump may be losing its prime or may be too weak.

I wanted to confirm this by attaching a fuel pressure gauge.

Second Test:

Fuel pressure gauge connected to fuel rail

When attaching a fuel pressure gauge, you want to be extremely careful because you are working with flammable fuel. Take all necessary precautions beforehand.

The fuel pressure that this system normally has is around 58 psi.

When cycling the key two times, it shows a crazy result. Check out the pictures below.

First key cycle. Around 10 psi.

Second key cycle. Around 53 psi.

3 seconds after the second key cycle. Around 10 psi.

After checking and finding no massive fuel leaks, it’s obvious that

This fuel pump is losing its prime and not holding pressure.

The first key cycle barely reaches 10 psi of fuel pressure, the second key cycle reaches normal fuel pressure, and seconds after, it drops back down to 10 psi.

This truck needs a fuel pump.

After replacing the fuel pump, this truck started like normal. Fixed!

---

Disclaimer and Disclosure:

Due to factors beyond the control of DiagnosticMechanic.com, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. DiagnosticMechanic.com assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. DiagnosticMechanic.com recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this website.  Due to factors beyond the control of DiagnosticMechanic.com, no information contained in this website shall create any express or implied warranty or guarantee of any particular result.  Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this website is the sole responsibility of the user and not DiagnosticMechanic.com.

DiagnosticMechanic.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. In many of our case studies, articles, and tool reviews, we may earn a small commission when readers purchase products through our links.