UPDATE 2/17: Shepherd Engine Saga Continues - third drive - about the same

[niles500]

Well without the unit throwing a code - the usual suspects are

1) Air Intake

2) Wrong ECM power program

3) Charge air cooler leak

4) Fuel restriction/leak (remember what happened to Sean Welsh when they RR his mill)

http://www.busconversions.com/bbs/index.php?topic=5153.0

[blue_goose]

Jim
I have a DD4 on my engine and it will go to full boost when cold.  You are not going to smoke, because the ecm won't let you have more fuel than you need for the boost you have.  I have an extra boost sensor if you would like to try I will mail to you.  The plug on my spare is a 3 wire plug.
Jack

[luvrbus]

Jim, I spent several hrs going through manuals on different engines and what I can read is all the major engine manufactures Cummins, Cat,DD, and Volvo the electronics control the HP rating till operating temperature is reached Volvo is a 190 degrees the highest.

I am go to ALB NM this week and will pick your waste gate turbo up on the way and ship it from there.
Fwiw I don't think I would want 30.2# of boost on a cold engine that's where your waste gate turbo is set at now according to the serial number you gave me



good luck

[rv_safetyman]

Niles, of the items you mentioned, the most logical is some sort of fuel starvation.  I pressure checked the charge air system.  I did not use soap, but did cure some obvious leaks. 

For the fuel, I will look the SilverLeaf again, but I think it had some fairly high flow rates on the first test suggesting that restriction is not a problem.

My tattle tale does not indicate an inlet restriction.

Jack, thanks for the offer.  I have a DDEC III sensor, but would have to adapt the wiring.  Hold off mailing until I make another test.

Clifford, thanks for all of the work you have done on this "adventure" of mine.  As far as the turbo, I will be in Albuquerque in mid-March for the FMCA event.  If Jim (or one of the other Albuquerque group) does not mind, maybe you can leave it with them and I can pick it up.

Jim

[luvrbus]

Jim, I'll leave it at Jim's Smith shop he is just 2 blocks off of I 40   



good luck

[Just Dallas]

Removed

[luvrbus]

Dallas, that is a good place to check Jim has a 3 pc manifold and replaced 1 section with a new one and Cole thinks he has a leak also.



good luck

[rv_safetyman]

Clifford and Dallas, interesting thought.  I did use new gaskets and torqued the bolts according to specs. 

As you know, the three piece manifold relies on "interference" to seal the joint (slip joint rather than a bolted joint).  I did clean up the joints as best as I could.

Trying to determine a leak will be a challenge.  As I have noted, I have exhaust blankets on the manifold and  turbo.  they are not easy to get off and I would suspect that you can only detect the leak by having access to the exhaust area when the bus is under load.

My guess is that the DD design relies on "corrosion" to seal the joints.  I know it was not fun to break the joints loose to put the new part in.

Jim

[blue_goose]

When you start the engine there is always a puff of smoke,  If you are looking at the engine when it is started you should be able to see some smoke as it is started if you have a leak.
Jack

[JohnEd]

If you hook a long metal hose to the end of a stethoscope you can insert it between the blanket and manifold and listen for hissing or putting.  I have done this many times and you can get a real good idea of where the leak is just by pointing the, I used copper tubing, end in the direction of the leak. Main point is that if you can work the hose all the way around the manifold and not hear any leak you have none and can look elsewhere.  The beauty of the copper is that it can be bent/formed to allow the open end to point directly at the underside to max the volume of any hiss.

Intake manifold is harder to hear and you need to be right on top of it BUT it can be heard with the steth.  First take a can of carb cleaner and spray around the gasket.  Spray around all the intake hose as well.  My logic is that they dump propane into the intake to boost power so a little flamable vapor would have an affect but wouldn't harm anything.  Nice to get a nod from Clifford on that, to be sure.

HTH,

John

[rv_safetyman]

Jack, I will station Pat in the bedroom with the engine hatch open when I start it for the next test.

JohnEd, good idea. After the next test drive, I will try that if getting the engine up to temperature does not resolve the issue.

I am not sure when the next drive will be.  It snowed again today and the rest of the week looks pretty grim in terms of both temperature and snow again later in the week. 

I am really tired of this winter weather.  Last week I tried to solder a couple of connections in the transmission bay and I had a heck of a time getting the wire up hot enough to flow the solder.

Jim

[rusty]

Jim, I will be going through Albuquerque this week if you want me to pick up the tubro I will. Give me a call.

Wayne

[rv_safetyman]

Wayne, that would be great.  However, I am not sure when Clifford will be there.  If it works out, that would be great.

Jim

[ArtGill]

Jim,
     this is a SWAG and may have been already covered, but make sure all your injectors are plugged in and working.  On my 6V92TA, I had one side come unplugged and the bus still ran, but performed poorly as expected.  The DD shop in Fla chased it around for several days.  Just a WAG.

Art

[luvrbus]

Wayne and Jim we will be in Albuquerque on Tuesday through Friday or maybe longer depends on how long it takes Jim to spray the battery compartment and stairs give me a call on the cell


good luck