Call Clay... he'll tell you what you should and shouldn't have to replace.

 

Without catching up to somebody and having at the very least a buzz test done, preferably followed up by a rotational velocity scan, i would not jump on the "needs new injectors" band wagon yet.

This could also be as simple as a sticking IPR. If anyone is near the OP with AE offer up ahand and lets get this man taken care of....

 

I agree... what's your location? I'm sure there's someone near you that could run some tests with AE...

 

What? I mean, sure - thats a possibility, but a distant second to GPR or GP's. Of course, some people like to throw $$ at problems... I usually like to KNOW whats wrong first!

Did he post his location yet?

 

I did not read if he .

1) made sure his Glow Plug Regulator worked
2) Ohm ed out the Glow Plugs to see if they all worked.
3) checked the wire harness going under the valve covers for looseness.

 

I did cross the gpr, no difference, did not ohm glow plugs. Thinking since I have very little smoke the culprit is injectors. At cold start, when it does, it can idle for a long period of time with no improvement till you excellerate, then it will run great, but up to that point it sounds like it is only running on 4 cylinders. that is why I am leaning towards injectors. Don't think wire connections could fix themselves at warm-up and not appear again till it cools off.

 

What is an IRP?

 

IPR = Injection Pressure Regulator

 

How do you test the IPR?

 

You need a scan tool to be able to watch it and make sure it's behaving correctly.

 

My truck was running real rough a few weeks ago. Turned out to be a loose uvch. Plugged everything in, secured it with the 50 cent mod and repaired the passenger side with safety wire. Working great now. Not an expensive parts needed was the best part

 

Does your truck have two relays like in the picture in post #6? If so, did you jump the one closest to the firewall? Just double checking. If you try to fire that truck off on a
80* morning around here and it doesn't start pretty quick, I don't think your having glow plug issues. Did you say you come my direction for work?

 

The highlighted statement above leads me more to belive it is the IPR. Until the PCM calls for more injection pressure by the IPR, If it is sticking the truck will Romp, sometimes with very little smoke. When the IPR is commanded by the PCM to supply more pressure the edge filter in the HPOP(high pressure oil pump)will close off and let less oil flow by thus increasing the pressure to the injectors. If when cold, the edge filter is stuck in a more closed position, and the PCM calls for less fuel for the injectors it can create the scenario as you describe above. The IPR is a plunger controlled by an electromagnet, which is contolled by the PCM.

Wiring connections CAN fix themselves after warm up just by the simple laws of heat expansion. The UVCH(under valve cover harness) has the same type of 9 pin connector that you see on the outside of the valve covers except is has a locking mechanism that is known to loosen over time, the common fix for this is called the 50 cent mod (it involves taking two quarters and fileing them down to act as shims between the the connectors)

We are trying to save you some bucks by asking you OHM out the Glow plugs, and to verify that the GPR is engaging. Iam sure you will agree that $200 or less and a little bit of your own labor is much better than spending $1600 to $2000 on injectors.

After reviewing the thread I see where you are located in central Texas, we have some very knowledgable members in Dallas, Austin, Houston, and also the Lake Charles area of LA, all of which I bet would be happy to help you, but it may take some coordination between parties. Now with that being said I would also recomend Diesel Innovations in Houston TX as a reputable shop . The owner, David Lott, is a member of alot of the diesel forums and his shops livelihood rests on the recomendations of the diesel community.

 

Brandon in post #73 has given you some very good advice.

Also,

We still do not know if the Glow Plug Regulator is working.
Go to Walmart and in that Auto section, buy a cigarette lighter plug-in Battery Volt checker for around 15.00. This will

1) When you turn the key on the 12.5 volt will drop to around 11.5 volts as the GPR is 'on' and working. If you do not see this volt drop then you have an issue with the GPR system.
2) Start the truck up and the voltage meter will come up to around 12.5 volts because the Altenator is on.
3) When the GPR shuts off the voltage should slowly climb to 14.5. this will show you that the Altenator is working the way it should.

Now ohm out the Glow Plugs and Pull the valve covers and check for loose wiring And retorque you Rocker Arms and Injectors, while you have the valve covers off.

Hopefull by this time someone is helping you with the IPR. I am not 100% sure if you can just take it apart and clean it, if it is sticking.

 

I really do thank you guys for the help. My 'mechanic" didn't mention any of these other possibilties,maybe I should tell him to spend some time here.