Where to start with a no start problem?

[kedlin88]

Wednesday i drove my truck around all day with no problems. I pulled up to Dollar General about 2 miles from my house, got my stuff and came back out to go home and the truck wouldn't start. It just turned over. Tried multiple times but no start, just keeps turning over. So i called a buddy to come tow me home. I'd say about 10 minutes later as i was waiting on him, i tried to start it again and it fired right up with no problem. So i drove it home and shut it off, started it again with no problems sitting in my drive way. 

 

Friday morning it started up with no problems, drove it about 10 miles and came back home. Truck sat for about an hour, I go out to start it up and again, no start. Just keeps turning over. Let it sit about 10 minutes, and it fired right up. 

 

I checked codes, and none show up. When i turn the key on, the wait to start light comes on every time and the fuel pump primes. 

 

I also noticed, when it doesn't start, the fuel pump doesnt run the 25 seconds like it should after a no start. And i have no fuel pressure while it is cranking over.

 

After it does start, fuel pressure is 17psi at idle and 15.5/16 psi at wot.

 

With no codes, I really don't know where to start.

 

Thanks,

 

[Yankneck696]

Loosen the fuel filler cap & see if that helps.

Ed

[kedlin88]

Thanks, next time it acts up with a no start ill try that and see what happens. 

[mopartechnician]

Yep sounds like vacuum in the tank. Mine would only do it after driving for awhile

[kedlin88]

I will be driving the truck tomorrow around town, so hopefully it acts up on me so i can see if it is vacuum in the tank. Just a question, how does the vacuum in the tank cause the no fuel pressure while cranking?

 

Also, what is the fix for vacuum? Is it just a new gas tank cap or something deeper?

 

Thanks,

Edited December 28, 2014 by kedlin88

[Dieselfuture]

To me it doesn't sound like vacuum, I had something similar happen few years back, and like you said fuel pump doesn't prime after you get done cranking, I jumped my relay plug for fuel pump and then pump stays on all the time and truck fired right up. But I don't think I ever found out what was wrong with mine, later in day pulled jumper out plugged it back to relay and never happened again. Maybe ECM maybe fuel pump maybe even vacuum, let us know what worked.

[gassernomore]

i have had this type of problem when the key fob auto lock button gets pressed before the key is put in the ignition. Engine cranks but will not start. Pull the key out of the ignition press the unlock button and insert the key back in and success!

[mopartechnician]

If you have vacuum in the tank your pump cant supply fuel to injection pump. For whatever reason having the pump wired to a constant power (wiper fuse) seems to help. Why it builds vacuum, thats a good question. I just left my cap loose and I sold my pickup before I got to look into it farther. I would look at the roll over valves being plugged

[Mopar1973Man]

Diesel require 2 things to run.

 

1. Compression

2. Fuel

 

So working on the fuel side. Does the Wait To Start come on instantly? Do you have fuel pressure from the lift pump? Do you have a fuel pressure gauge? How about any error codes?

[Yankneck696]

What about that silly air stuff?

 

Ed

[kedlin88]

Drove it around town and it never acted up on me. Shut it off and restarted it about 10 times through out the day. 

 

Yes, wait to start light comes on instantly

No, there are no codes at all.

Yes, when it is running i have 17 psi at idle and 15.5/16 at WOT.

No, there is no fuel pressure while cranking when it wont start. When it does start, there is fuel pressure while cranking.