Engine/Transmission (1994 - 1998) 97 Starting Question - Long Cranking Before Starting

[Bob95065]

My 1997 2500 in my signature started weird while on a 4x4 trip last week. One of the guys I go offroad with has a 1996 that he bought brand new. It is bone stock. My mods are in my signature.



My truck always cranked longer than his to start. If I gently rest my foot an the gas pedal it will start faster than normal. Last week we were out in the desert (100° F) and the truck wouldn't start UNLESS I rested my foot on the gas gently. If I didn't do that the engine wouldn't start at all. The next day it started normally. I noticed as the day wore on it cranked longer before starting.



I know I don't have an air leak because the truck started normally in the morning. If I had a leak it would be hard to start after sitting all night.



I am scared my IP is starting to go. What could cause this? BTW the truck has 240k on the odometer. Could a failing lift pump do this? IP pump? Let me know what I should check.



TIA,



Bob

 

[ata]

If your idle speed is set lower then 850 rpm that is part of your problem. Having to step on the go pedal is telling you that.

 

[gcorron]

Idle speed is the first culprit, and something you can do for free.

My 97 had the same issue, idle speed helped, but did not completely correct the problem. Put in a new overflow valve, the problem was solved!

Good luck,

George

 

[Bob95065]

The idle speed is correct. I didn't have a problem before last week. I had the truck for 5 years.

How do I check for a defective overflow valve?

 

[Bob95065]

If this is an overflow valve problem why does it only happen when the engine is hot?

 

[ata]

If this is an overflow valve problem why does it only happen when the engine is hot?

The spring in the over flow valve wears out as all springs do and will not hold the fuel pressure need. When the engine is cold or it's cold out side your fuel is heavier (thick) = higher fuel pressue. When you run your truck the fuel is returning to the tank which heats it up and the outside air temp also heats it up so the fuel is thinner = lower fuel pressue. So when the spring is weak and the fuel and engine are hot the fuel pressure is to low to start until the engine turns over a few times to build up pressure and start the engine.

 

[MLee]

Check when hot, the fuel Solenoid is lifting properly. Try lifting it manualy when hot, see if this makes a difference. Maybe it needs to be cleaned, a little TLC might be requird.

 

[BigPapa]

Bob, I wouldn't sweat it. I've had to give mine a little pedal to start for the last 400K miles.



Every 2nd Gen 12V I've ever been in was basically the same way. Some would start up pretty quick but, from habit, I always gave them a little pedal. My techs, most who specialized in Fords (since Dodges rarely give problems), would crank and crank on them and they'd start right up for me. Kept them aggravated which was always fun.



There are a couple of adjustments on the pump that will help but it will never start like a VE, VP, or CR truck.

 

[gcorron]

As an also to this thread, because it may come up in future searches.

I have never had to feather the throttle to start my truck, until the idle, and overflow valve needed attention, EXCEPT, a couple years ago it required feathering, and about a month later, I finally noticed diesel fuel under the fuel door.

I discovered the lines had rotted between the tank and the frame. The fuel tank module lines had also rotted! Replaced, end of that problem. It does not sound like your problem, but will cause long starts.

George

 

[gcorron]

As an also to this thread, because it may come up in future searches.



I have never had to feather the throttle to start my truck, until the idle, and overflow valve needed attention, EXCEPT, a couple years ago it required feathering, and about a month later, I finally noticed diesel fuel under the fuel door.



I discovered the lines had rotted between the tank and the frame. The fuel tank module lines had also rotted! Replaced, end of that problem. It does not sound like your problem, but will cause long starts.



George

 

[Bob95065]

As an also to this thread, because it may come up in future searches.



I have never had to feather the throttle to start my truck, until the idle, and overflow valve needed attention, EXCEPT, a couple years ago it required feathering, and about a month later, I finally noticed diesel fuel under the fuel door.



I discovered the lines had rotted between the tank and the frame. The fuel tank module lines had also rotted! Replaced, end of that problem. It does not sound like your problem, but will cause long starts.



George

No, this isn't my problem. I replaced all the rubber lines when I bought the truck 5 years ago. I live is California so snow and road salt aren't a contributing factor to my problem.



I think I am going to get the truck nice and warm and use a clamp to pinch off the return line. If it starts normally I narrowed the problem down to the overflow valve. I am also considering changing the lift pump and carrying the old one as a spare. I am at 245k on the odometer and I don't know how long the lift pump has been on the truck.