Everything running smooth as usual this morning, I crossed a railroad crossing(not very rough either) and truck just went dead, all gauges reading fine. The truck will turn over but won't start
Any help would be greatly appreciated

Thanks

 

I'm assuming you've got good fuel pressure.

Check the wire tap for the Comp, make sure you've got a good connection. I've heard that a bad connection here can shut down the truck. Check the major electrical connections under the hood, especially around the computers.

 

Start with the basics...fuel, filter, batteries, lift pump, loose wire, fuse...?

 

Check for codes before you bother pulling anything apart......there will most likely be some.

 

....and, oh yea, be sure to check of codes.....

 

a bad ckp will also cause this situation but most of the time truck will stumble and or shut down...tack will drop to zero with engine running before it shuts down.

 

Checked codes using Mac Tools MasterCraft Scanner, pulled PO236, PO237.
P1688, Looking like the injector pump from what i've read so far, Anybody else have any ideas other than that?

 

P1688 is the big one there!
It's... "Fuel Injection Pump Internal Controller Failure"!
Sorry Does not sound good...but have not actually seen that one before. May or may not be a dead Inj Pump...but your symptoms (fine one minute...dead the next) sure sounds like it? Probably need to ck with a dealer....for info only, not for replacing the pump!!!

RJ

 

P0236
MAP Sensor Too High Too Long

P0237
MAP Sensor Voltage Too Low

Sounds like your MAP sensor is punched and as RJ mentioned, the 1688 means that there is an electroinc failure within the VP44 ECU which is mounted on top of the pump. Unfortunately, this module is a repair by replacement type of part and is not independently servicable from the VP44 itself so it is probable that the VP44 will have to be replaced, I'm sorry to say.

 

I would replace the MAP (boost) sensor first, erase the codes and then take it for a drive and see what happens. Maybe I'm too optomistic.

 

would my comp box be causing the map sensor codes ?
Do you think a map sensor would let me start the truck (won't start) no fuel to the injectors.
Would the map sensor cause that?

 

Yes, the comp messes with the MAP signal, so it could cause the faulty readings.
No, you can disconnect the MAP completely and the engine will start and run, just a bit more smoke than normal.

I'd have to say VP44 has died, or is intermittently dying.


phox