I'm at a loss. Everything its cold (35-40 degrees or less) and the truck is not plugged in it won't start. Like nothing....

I'll plug it in and let the EBH work for a little and it will crank over and fall on its face. Leave it plugged in for a while longer and it will finally stay running. (not happily) It is ignorant, nasty and shakes like an earthquake when its could. Once its up to temp you would never know anything like this is going on.

In my mine it has to be one of two things. Tuning or Injectors but I'm opening up to other possibilities...

This all started last year when we pull the engine and did the injectors and a bunch of other things.
BigRed's Engine Pull

Here are a few pictures from Screen Shots from AE and a couple videos of it trying to start. I have a excel file of data logging but can't figure out how to get it up here, so if anyone could look at it and point me in a direction I would extremely grateful.

1100 RPM CCT


Idle CCT








Let me know what you think...........

 

Unplug your VC pigtails up top and ohm out your Glow Plugs.

If that checks out, hook them back up and short your GPR posts manually for 30 seconds and try to start the truck again.

 

All the glow plugs were replaced when the engine came out but I'll give it a try. The should ohm at 3.1 or something like that right?

 

The injectors are about 3 ohms, but the glow plugs are lower. I'm not saying you have bad GPs, but the tests I suggest ensure there are no electrical connection issues... a common bane of the 7.3L

 

For the Excel file you can make the data into a graph by using Excel as well. After u make the graph you can save it as a picture and post it like u did the others..... If u have problems just let me know.

 

Mike, did you run a buzz test? I watched the videos. Sounds like an injector issue. Are you starting on diesel or grease?

 

Starting on diesel. Way to cold to even try to start on grease. I don't go to grease until EOT is 120 and coolant is 140.

I did run a buzz test and sounded ok in the cab. I'll record on with the phone in the engine compartment.

Going out now to ohm out the glow plugs...

 

New glow plugs should ohm between 0.6 and 2.1 ohms, plus the resistance in the wiring harness of maybe half an ohm or so. The resistance changes as they age, but any that are very high or infinite are a problem. Could be wiring, or the glow plug itself.

 

Buzz Test Results, sounds fine to me.....

 

Its been a long time since I paid attention to a cold start but your DC seems a little high for idle. At least a warm idle. I never noticed what mine was like on a cold start. Any chance the tin nut has come off the back of the IPR?

 

Ohm'd the UVCH. Each glow plug read 1.2ohms with 1 reading 1.1ohms. Verified that there was 11.5 volts on battery side of GPR and 11.5 volts on switched side while on. KOEO

I'm going to go ahead and rule out a glow plug issue....

The wire harness looked good with no burn marks. Dark marks in the pictures are from my dirty gloves touching them.

Driver Side


Passenger Side

 

Did you try jumping the glow plug relay like Tugly mentioned?

 

Sorry Peter, I just noticed this. That 34 you see isn't duty cycle. That engine oil temp...

 

I haven't had the chance yet. This condition only really shows it's ugly head when the truck sits for a couple of days. Been driving it more now and haven't had the chance to do this.

I did however order a Stancor relay. I needed new dust seals and stub axle seals so I ordered a relay also. I'm currently using the AIH relay for me glow plugs. My original glow plug relay died last year and I took out the AIH a while ago.

Aside from the GPR being bad does is sound like it could be anything else?

 

I would check the glow ply system and starter first. According to Your description it seems to be glow plug related since your injectors were just done recently. So it only does it occasionally ?