Truck shuts off but starts back up

[Greengiant]

Here is a good one I have been fighting,

truck shuts off like you turned the key off while driving but wait a few seconds and it starts right back up, but if you try to just start it back upwithout waiting it will just crank. No codes, doesn't crank like it ran out of fuel just starts back up. Could it be a ground? New vp44, App, alternator. Yesterday day on a 300 mile trip it did it more often like something had to cool down. I'm thinking maybe computer? 

[Me78569]

so I am assuming you are using the key to start the truck back up?  how many seconds?  

 

How are are you scanning for codes?  Sounds to me like a bad crank or cam sensor, but typically you see a code.

[Greengiant]

Yes using the key to start it back up. check engine light is not on and my scanner doesn't pick up any codes. One to 10 seconds and starts back up no problem

Edited August 10, 2016 by Greengiant

[TFaoro]

ECM starting to die???? Just a guess though.

[Greengiant]

Hasn't done it in a year, thought the new alternator fixed it but yesterday on a 300 mile trip it did it about 170 miles in then again about 30 minutes later and again about same time. 

[dripley]

Do you every have delayed start from a cold start?

[KATOOM]

9 hours ago, Me78569 said:

so I am assuming you are using the key to start the truck back up?

 

I was going to ask the same question.....or assume the truck is haunted.

 

If I understand the situation, it sounds like the truck simply doesn't like to re-start not long after shutting off when the engine is at full operating temperature.  Correct?  If so, we call that a "hard hot start".

 

If this is the problem then a few questions:

Has the VP been replaced?

What fuel pump are you using?

Whats the running fuel pressures?

And just to make sure.....this ONLY happens when the engine is at full operating temperature?

[Greengiant]

Starts right back up, no problems. Not hard to start in the cold. Vp was replaced twice thinking that was the problem. Even replaced the fuel pump with rapter about 19 psi idle. Leaning towards ecm problem. you never really know when it's going to do it, drove 600 miles yesterday and never missed a beat and there were some long big hills. Just like someone reached in and shut truck off. Wait 5 seconds and starts back up?

[JAG1]

Does the 24 valve have the fuel shut off solenoid like a 12 valve does?

[KATOOM]

So you have to sit there and let it "automatically" start back up on its own?????

[JAG1]

25 minutes ago, KATOOM said:

So you have to sit there and let it "automatically" start back up on its own?????

I think he said it shuts down on its own without warning, then like something has to cool off, wait a few seconds or minutes to fire it back up with the key again.

[Greengiant]

Yes, I have to slow down and stop put it in park shut it off turn the key back on and it starts right back up. Doesn't crank like it ran out of fuel has like a 1 second crank and starts right up. I have worked with allot of diesel's and this one has me baffled. No check engine light or codes. ECM is spendy but so was the industrial injection vp pumps so I hope that fixes it, we will see when I get the money to change it. I am going to do some more test first before shotgunning it with an ECM. Just wondered if anyone had a similar problem.

[JAG1]

I would look into the items connected with what makes en engine shut down when the key is turn to the off position. I don't know if the second gens had a fuel shut of solenoid or what is responsible for shutting them down with the key. Something is shutting it down like you were using the key, I think that's what is causing the problem.

[dripley]

ASD relay on its way out maybe? It would be easy to swap out and see. just guessing.

[JAG1]

thank you' Chicken man' I knew I could count on you for that. Could be associated with an electrical current interruption to the ASD relay too.

[Hawkez]

I would have your alternator test for AC voltage.  Also, go over and check all of your battery cables.  What scanner are you using to check for codes?

[02snimmuc]

Hey Greengiant, did you get this issue figured out? If you did i would love to know what it was. Im having the exact same problem. The first time was about 2-3 months ago, I left are cabin for home, its long rough lane and half way out just shut down like if I would have turn the switch off. Sat there for a minute puzzled scratchin my head, hit the switch, started right up like nothing happened, drove 250 miles to home with out a problem and nothing since until last night. I was coming home from town pulled up my driveway halfway and shut down! Pushed in the brake so it wouldn't drift, put it in park, hit the switch, started right up without hitch. Drove fifty feet to the top of driveway, got out looked under the hood, everthing seemed fine. This morning went out started it to warm up. Went to town, came home without a problem. Go figure??? Seems like a problem in the switch or ground issue maybe, i dont know, im not an electrical guy. Anybody with ideas or suggestions, PLEASE chime in!

[klcammie]

What year truck? My 01 would shut the fuel pump off due to a loose connection.  Is lift pump still running off ecm? Maybe needs a relay.

[Hawkez]

@02snimmuc did it ever throw a check engine light? or have you checked to see if there are any codes?

[02snimmuc]

KLcammie, the trucks an 02 and I have an Airdog installed. Hawkez, no check engine light and no codes. Seems to me like it's an electrical issue. It's only second time it's happened but I don't like it. You never when it going to shut off, could be kinda dangerous.