Hard to start

Tiny
05RAM
  • MEMBER
  • 2005 DODGE RAM

Quite often and not all the time, my ram will crank over for maybe 5 or 6 seconds before starting. I thought it may have been a dirty/sticky throttle body but I have removed and cleaned throttle body which was quite dirty and it still did'nt fix the problem. Can anyone help me with this issue?
Sunday, July 25th, 2010 AT 6:46 PM

85 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,563 POSTS
Actually, the problem sounds like you are losing the fuel pressure prim when the engine is shut. Here is a how to for checking fuel pressure, regulator, and drop off. When you shut the key, the pressure should hold steady. If it drops quickly to 0PSI, we need to check for a leak, fuel filter anti flow back valve, bad fuel pump, or regulator. Check it and let me know what you find.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

NOTE: You will need a fuel pressure gauge. Most parts stores will lend or rent them to you.

Let me know what you find.
Joe
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Monday, July 26th, 2010 AT 12:43 AM
Tiny
STEVE REID
  • MEMBER
  • 1 POST
  • 2003 DODGE RAM
  • V8
  • 4WD
  • AUTOMATIC
  • 220,000 MILES
Truck will start some of the time but only after a lot of cranking and hitting the gas several times
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
CARADIODOC
  • MECHANIC
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Possible coolant temp sensor? If the engine computer thinks it's warmer than it really is, it will not command a sufficient priming squirt from the injectors. Look for the two-wire sensor. The single-wire temp sensor is for the gauge on the dash. Chrysler doesn't have much trouble with temperature sensors; Ford has a lot.

Also possible low fuel pressure or the pump isn't starting right away. GM trucks won't run at all if the fuel pressure is just a few pounds low. Dodge trucks will run, but may develop problems such as yours.

If fuel pressure is bleeding off while the trucks sits for a while, suspect a leaking injector. You can prove this by cycling the ignition switch on for a few seconds without cranking the engine. Turn it back of, wait five seconds, turn it on again, and maybe do this a third time. Every time you turn it on, the fuel pump will run for two seconds, then stop until the engine computer sees engine rotation, (cranking or running). These two or three bursts from the pump will insure pressure is up and ready for starting. If it starts right away now, an injector is leaking, or the pressure regulator or pump check valve is leaking. I think by 2003, your regulator is in the tank, not on the fuel rail on the engine. I would just live with those because of the cost of a new fuel pump assembly, but if it's a leaking injector, raw fuel will be dumped into the intake manifold after you shut the engine off. The fuel could run down past the piston rings into the oil, reducing its lubricating properties. This isn't quite as critical if you do a lot of long trip driving, like 15 - 20 or more miles. Long trips with the engine fully warmed up will tend to vaporize the fuel in the oil. It will get drawn out through the PCV valve and burned.

Caradiodoc
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
C.KARKHOFF
  • MEMBER
  • 2 POSTS
  • 2002 DODGE RAM
  • V8
  • 4WD
  • AUTOMATIC
  • 109,000 MILES
Engine struggles to start after sitting for a period of 4-6 hours or more. The problem is very intermittent. It may happen today and then not happen again for a month. Not sure, but wet conditions seem to trigger the problem. (Rainy, damp weather) I have replaced the distributor cap and rotor already. Problem still exists. Fuel pump seems to be operating just fine. I have tried turning the key 6-8 times before starting and doesn't help. After it starts, it runs perfect and continues to start fine all day.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,563 POSTS
Have you tried replacing the ignition wires?
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
C.KARKHOFF
  • MEMBER
  • 2 POSTS
Thanks for the feedback. I have not done that yet. Could moisture in any way effect the ignition wires?

Nonetheless, I will give it a try.

Thank you.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JACOBANDNICKOLAS
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Yes it can. As far as the wires, they could have too much resistance in them which can cause a weak spark. Add water to the mixture, and they can arc and short.

Check it out and let me know what you find.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
TERRYL50
  • MEMBER
  • 1 POST
  • 2002 DODGE RAM
  • V8
  • 2WD
  • AUTOMATIC
  • 158,000 MILES
The truck takes approximately 3 cranks before starting. Once it starts it's fine. This occurs everytime I get in the vehicle. The engine light is on as well. What is the problem? I have tried several things and nothing works including changing the spark plugs. Please advise! Thanks!
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Check fuel pressure
also need to check for codes
an OBDII reader should help
most local part stores can help in getting the codes
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JDG25
  • MEMBER
  • 1 POST
  • 2002 DODGE RAM
  • V8
  • 2WD
  • AUTOMATIC
  • 85,000 MILES
I have a 2002 Dodge Ram 1500, 5.9L. After the truck sits for a period of time it is hard to start. If I turn the key on and off a few times and let the fuel pump cycle before starting it will fire right up. Do I need a new fuel pump?
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
What is a period of time?
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Check the fuel pressure if its within specs-seems to me its losing fuel pressure due to a leaky injector/s, fuel pressure regulator and fuel pump check valve
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JUROME
  • MEMBER
  • 1 POST
  • 2001 DODGE RAM
  • 5.2L
  • V8
  • 4WD
  • AUTOMATIC
  • 120,000 MILES
My trucks motor will turn over but its takes awhile for it to fire and when it does it runs real rough for about 20 seconds. I've replaced the crankshaft sensor twice. When you get it started you can let it run for a minute and turn it off and it'll start right back up but if you let it sit awhile it'll mess up again. When you get it started its also not idling right. The RPMs just go to zero unless I hold down the accelerator.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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The first thing I recommend checking is the fuel pump pressure. See if it is within the manufacturer's specs. Also, see if it is dropping off quickly when you turn the key off and if it is building pressure quickly when you first turn the key on.

As far as the idle issue, it could be a vacuum leaks, the idle air control valve. Wait to see what the fuel pressure turns out to be and then we can move on.

Let me know what you find.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
NORTHSHORE1
  • MEMBER
  • 6 POSTS
  • 2001 DODGE RAM
  • V8
  • 4WD
  • AUTOMATIC
  • 74,000 MILES
My 2001 Dodge Ram 1500 with a 5.9 engine never starts on the first crank and always starts on the second crank. If I restart in 10 minutes or so, it starts right up. Any longer, then it's back to 2 cranks. The fuel pressure jumps right up to 45PSI when the key is turned to the on position. But it drops right down to 0 after the key is turned off. Is this normal? Shouldn't the fuel rail always have some kind of pressure reading?
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
NORTHSHORE1
  • MEMBER
  • 6 POSTS
Should have included this info.
No codes.I checked
Truck runs fine except for the hard start condition. The plugs are fairly new. Bosch Platinum.
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,563 POSTS
The fuel pressure running should be between 44 and 54 PSI. When you shut it, the pressure shouldn't drop below 30 PSI for 5 minutes. If it does drop, you have a leak. Try this:

Start the engine and allow it to warm up. Next, clamp off rubber hose portion of fuel line pressure test adapter between fuel rail and test port T on fuel line pressure tester adapter. Note shut engine when you clamp the rubber hose. If the pressure does not fall below 30 PSI within 5 minutes, the fuel rail or an injector is leaking. Next, do the same, but place the clamp between the rubber hose of the fuel line pressure tester adapter and the fuel line and test port T on fuel line pressure tester adapter. If it doesn't fall, the injectors and fuel rail is good. That leaves a fuel pump check valve, fuel pressure regulator check valve or a leak in the fuel line.

Note: A slow pressure leak usually indicates a bad check valve in the fuel pump. A quick drop usually indicates a bad check valve in the fuel filter or regulator.

Let me know if this helps and what you find.

Joe
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
NORTHSHORE1
  • MEMBER
  • 6 POSTS
If the fuel rail was leaking, I would have definitely seen this so I think I can rule that out. I think I understand what you what me to do. You want me to isolate the injectors from the fuel rail back to the pump module to see which is causing the sudden pressure drop. Just so we're on the same page. When the truck is running, the pressure is 51PSI so I think we're good there. When I shut the truck off, the pressure drops to 0 PSI immediately. So either an injector is staying open or the fuel pressure regulator / filter/ check valve is faulty. So with the engine running and the pressure gauge screwed in to the test port, clamp the rubber part of the fuel line just before the fuel rail then shut the engine off. If the pressure drops, then it's an injector. If not, then it's the pressure regulator on the fuel pump module, correct? I think that the way it dropped off immediately with my first test, it's going to be the pressure regulator. But I'll try the test you recommended tomorrow morning and let you know the results. Thanks!
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Saturday, August 31st, 2019 AT 10:29 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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You have been around cars for awhile to have understood what I said. Yes, I'm trying to determine which part of the system is leaking. I feel very confident the quick pressure bleed off is causing the hard start. I doubled checked it in the manual (Mitchell online) and all of the pressures I gave you are accurate. And the bleed of times are correct too.

Let me know what you find, and yes again, you nailed it.

Joe
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Saturday, August 31st, 2019 AT 10:30 AM (Merged)
Tiny
JLINDEMAN
  • MEMBER
  • 2 POSTS
I have the same problem on my 2001 Dodge Ram.
I had bosch platinum plugs with only about 10,000 miles on them when my truck would just up and stall, sometimes while driving at 60 mph, then start right back up. The local dodge mechanic said that magnum engines don't like platinum plugs. I changed plugs and no problems since.
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Saturday, August 31st, 2019 AT 10:30 AM (Merged)

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