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

[rv_safetyman]

{{{2/13/10  I am updating this thread - see page 3}}}

{{{2/17/10 results updated see page 5}}}

Well, the saga continues.

First I would like to thank all of the folks who have called to ask how the replacement engine installation is going.  I have tried not to clog this great bulletin board with all my trials and tribulations.  I have told several folks that this bus and I have a love/hate relationship.  For the past few months it has been the latter.  Every component I touch seems to delight in frustrating me and consuming huge amounts of my limited resources!!!!

If you are really bored, you can follow all of the gory details of this saga in the following threads:

http://www.busconversions.com/bbs/index.php?topic=13609.0
http://www.busconversions.com/bbs/index.php?topic=12915
http://www.busconversions.com/bbs/index.php?topic=12668
http://www.busconversions.com/bbs/index.php?topic=12599.0

OK, now I need some help in thinking my way through the my latest problem (low turbo boost).  I just took the first drive around our subdivision (fairly big hills) and about the highest boost I saw on the SilverLeaf was 4.5 pounds (it should have maxed out at around 20-25 pounds).  I think the RPM was high enough to get good boost and I was at full throttle.  

I have pulled the cold side and the turbo spun very well.  This was my “old” Series 60 turbo that had 54K on it.  The turbo that came with the replacement engine had the bypass turbo, but the mechanism did not feel like it was working.  If it makes any difference, I am using my “old” ECM.

The first thing that folks think about is fuel starvation and fuel filter issues.  I use the FuelPro 382, which tells you if there is an issue (via the clear glass bowl).  Along that line, I had to work to get the flow established to the filter when I first tried to fire up the engine, but it seems fine now.  I can look at fuel flow rate on the SilverLeaf.  Sitting in the shop, and stabbing the throttle shows a spike in the flow of about 5 GPM (no load).  That would be flow into the engine and would not include the fuel bypassed back to the tank.

I have looked at the several silicone flexible connectors that connect all of the metal tubing to and from the charge air cooler.  I did not see any obvious sources of pressure loss.  If all else fails, I will make a couple of caps for that plumbing and test for leaks with compressed air.  That will test the whole system including the charge air cooler.

So, what great ideas do you all have about the low boost?

In addition to the turbo boost problem, my AutoShift range shift solenoid is throwing a code.  Thus I have gears 1-5, but not the top side.  I don't think that is a huge issue.

However, all of these issues put the last nail in the coffin as far as taking the bus to the big Quartzsite bash.  We are thinking about driving the service truck and staying in one of the two motels in town.  Part of that decision will be based on some pretty major health issues going on our daughters families.  Pat is not sure she can leave with all of that turmoil going on.

[DaveG]

I'd check the charge air cooler and plumbing...I believe you can rotate the engine to get all the intake valves closed and then pressurized it as far back as you can (towards the air cleaner).

I've been wondering how you were doing with that project. Thanks for the update, as it is.

[luvrbus]

Jim bet its your ECM controlling the boost disconnet the turbo sensor and try that to see if the boost stays the same also the waste gate may be stuck open.  


good luck

[rv_safetyman]

Dave, because of my crank hub adapter, it is not possible for me to bar the engine over very easily.  I think putting a cap at the turbo connection and another at the intake manifold will test everything in the system that would leak.

Clifford, I was not clear about the turbo.  It is a non-bypass turbo.

Jim

[Ednj]

jim,
Under load it may be sucking the pipe from the air filter to the turbo closed or the filter itself.

[rv_safetyman]

Ed, good thought. 

My plumbing is pretty robust in that area.  Several short pieces of steel tubing connected by short rubber connectors designed for that application.  The air cleaner is a truck type that would be hard to collapse.  I might take a drive in the next day or two (may be a small snow storm tomorrow) without the air cleaner.  My tattle tale typically shows some yellow bars, but it did not do that this time.  That suggest to me that the engine is not calling for much air, but not sure why.

I saw some black smoke when I first took off, but that was only for a short distance.  Tried to watch for that the rest of way, but I don't think there was much, if any.

Jim

[DaveG]

I understand. The nice thing about doing it with the valves closed it that it checks valves and intake also.

[Zeroclearance]

Check and recheck all your charge air connections.   You can install a test plugs and pressurize your charge air system to check for leaks.

Since you had problems with your other engine, I would remove the turbocharger and pull the turbine housing off to inspect the turbine wheel.   If you have damage to the turbine wheel your boost will be down.   

[luvrbus]

Guys I am not that great on a DDEC but Jim says he is not blowing black smoke so with what little I know about  it the DDEC is calling for the right amount of air for the fuel ratio to the engine right or wrong.
If he had low turbo boost would not he have the 34 or 64 code flashing may be the wrong codes but one is for the circut and the other is for turbo speed lol forgot which is which.




good luck

[Just Dallas]

Removed

[Busted Knuckle]

DDEC won't allow you to have more boost than you actually need anyway. Unless you can put a load on the bus by climbing a hill or pulling a load, you may never see full boost.. that is if the engine is running right.

Right but Jim mentions in the beginning that their "swanky" subdivision has HILLS , that should put a decent load on it!
  BK 

[blue_goose]

Jim you should be able to get boost with the brakes on in gear. Don't use enough power to damage the drive shaft or transmission.  Do you have another turbo boost sensor that you could try?
Jack

[c-coop]

Jim, I had the same problem it was a bad connection on the boost sensor that is mounted on the side of the intake manifold

[rv_safetyman]

Well, lets see if I can catch up. 

With the hills in the subdivision, I can get quite a bit of boost normally.  I don't think I can get full boost, but at least well into the teens.

There has been some discussion about the DDEC ECM controlling boost. From everything I can tell, the boost is not controlled by the ECM.  The turbo boost sensor is an input to the control algorithm.  Since it is a standard turbo (no waste gate), I don't see how it can be controlled.  If the ECM does somehow control the turbo, I would love to have someone point out a reference so that I can relegate that information to my tired ole brain.

Now, let me talk about what I did today.  I made two end caps (see photos) and put them into the system (please ignore the somewhat crude welding - I am still trying to perfect my TIG skills).  They were located so that they would test everything between the turbo outlet and the intake manifold.  I hooked up a pressure regulator set at 20 PSI.  I found two areas where the silicone connecting sleeves were not sealing.  One may have been leaking with the old engine and was not a major leak.  However, I did find one that was emitting a "screaming" or whistling sound.  It was a fairly substantial leak.  It was a connection that I had to disconnect to remove/install the engine.  I thought I had tightened it, but I must not have cinched it up all the way.

I did not get a chance to drive it today.  I will do that tomorrow.  My transmission problem will not allow the transmission to do the range shift, so I am limited to the bottom five gears.  I think I will still be able to work the engine hard enough to see if I have more reasonable boost.

I don't know how much leakage it would take to knock the boost off.  I guess I will find out tomorrow.

Jim

 

[Sean]

Jim,

We had this problem after our first rebuild.

Nothwithstanding the fact that we also have a Fuel Pro which might disclose flow problems, it turned out to be a fuel restriction -- the main supply line had collapsed internally.  Replacing the line cured the problem.  I discussed this in several posts in this archive:
http://ourodyssey.blogspot.com/2005_05_01_archive.html

You might hang a 5 gallon can of fuel with a #10 hose off the back and try it -- low cost way to check.  Just remember the engine will blow through 5 gallons in a heartbeat if you don't also plumb the return to the same can.

Also, FWIW, our fuel flow tops out at around 20 GPH (not GPM).  I'm guessing you meant to write 5 GPH,  which sounds low to me, and might be more evidence for a fuel restriction.  That said, I am not really familiar with the S60's rates.

-Sean
http://OurOdyssey.BlogSpot.com