Turbo HELP needed please

[homermandy]

1991 Eagle, 6V92TA DDEC2. Just took the bus on a 60 mile trip. Usually can build boost to 21lbs. The trip up was fine, but the trip back today was very strange. I noticed boost wasn't building as good as it usually does and I felt a little vibration when the boost wold build. I could only get about 15 lbs which for my engine is not normal. Power was much lower. I just got back and it is pouring rain so I was wanting to get a heads up help. All other guages were normal. I was thinking of checking all hoses around turbo and air filter. The strange thing is that it ran so great the 1st part of the trip, stayed overnight, then this happened. Thanks in advance for the help. Joe

[homermandy]

One other note. When idling in neutral and revving the engine (as well as 0-5mph), I notice a huge lack of power. Which makes me wonder if my fuel filters may be the problem(I'll change tomorrow) or another fuel issue. Any other items in the fuel system to check? Thanks

[belfert]

Curious, do the Eagles have boost gauges?  I read folks talking about boost, but I don't have a boost gauge in my Dina naad have no idea what my boost is doing.

Brian

[Nick Badame Refrig/ACC]

Hello homermandy,

If you find that the problem was the filters, I would go a step further and assume your tank is loaded with scum or algea.

I hope I'm wrong cause thats not fun to remove.

Good Luck
Nick-

[NJT 5573]

If the filters don't fix it check the plug ins on the DDEC box. It may have dropped a cylinder or two. No fuel, no boost. A truck engine is a little safer to work on and were it a truck engine I would cold start it and touch my hand to each exhaust port as it warmed up looking for a cold one or two. If its a DDEC issue for some reason it usually happens in pairs. On a bus with belt and safety issues you may need to run it in 30 or 45 second intervals and feel for a cold cylinder with the engine stopped. This is also a good use for your infared temp gun. The turbo won't often cause a vibration unless it grenades. I have lost injectors in both series 60 electronic and Cummins mechanical engines in the last 2 months and it may just be an additional cost of running ULSD. If you find one cylinder cold and not two, I see that as a strong indication of a physical problem with an injector.

[lloyd]

Are you noticing black smoke with low power? You might want to remove the intake side and the exhaust side of the turbo just to make sure there is no damage or excessive play or either wheel touching the snail housings.

[Jerry32]

I lost turbo boost on acummins once and the exhaust manifold had popped a bolt. Jerry

[Sammy]

Joe, checking all hoses,pipes and clamps to and from the turbo is the right place to begin your troubleshooting. You can also shut off your batterys, remove the hose to the turbo on the inlet side - the one that connects to your air filter- and check the small wheel inside the housing. Make sure it spins freely and does not bind or rub against the turbo housing.You mention that it's a DDEC controlled engine.
Did the check or stop engine lights come on? -  code for low boost?
I would definitely change the fuel filters next, as you already mentioned.
If your engine cannot make power properly-bad injector, dirty fuel filters, bad fuel pump- then it will not make boost.
Belfert, I ran 6 Eagle Model 15's in the fleet I worked with and they alll had boost guages on the dash. Hope this may help you.

Best of luck with your  troubleshooting.
Sammy 

[homermandy]

Thanks for all the suggestions. I am picking up fuel filters in a few hours and will let you know. No check engine lights went on at all. I would imagine if an injector failed, etc it would report a code? Thanks and I'll post this afternoon.

[homermandy]

Will, I think I found the problem. I changed fuel filters, started the engine, and felt all 6 exhaust ports. They were all hot EXCEPT the one on the right rear towards the front of the bus if you are facing the rear engine. Does this sound like an injector gone bad?  If so, is it a hard job and how do I test whether it is or not. I just had in in-frame rebuild last spring with new injectors, rebuilt heads, cylinde kits, jake bridges, etc. Only have about 2K miles on the engine. Thanks for the help.

[NJT 5573]

Homer, 2000 miles is not very many, its possible that an adjustment nut has backed off or tightened up on that cylinder. (Shop booboo). Especially since its in the back where its least accessable to adjust and lock down. Diesel engines also break rocker arms and bend push tubes. If it were a mechanical engine and nothing was bent or broken I would replace the injector. I also have DDEC2 and that is the wild card. If the "electronic" injector is not getting a signal from the ECM, its not going to fire. (Pinched wire, loose wire, broken wire, loose connection). Our new fuel is described as "very dry". That translates to low or no lubericity. Fortunately for us and our injectors there is a man in Riverside California who many years ago was faced with keeping his truck fleet running in extreme heat/desert conditions and he formulated products to stop gears from burning up, seals from drying out, as well as pistons and injectors from seizing. Forrest Lucas sells these products under the name Lucas oil today and the fuel conditioner is around $20 per gallon. If your DDEC2 seized an injector its too late for that one, but for everyone else, its not a good time to leave home without it. A gallon treats about 400 gallons of fuel if I remember right, cheap insurance.

[homermandy]

Well, I popped off the valve cover and took a look. It looks pretty complicated in there. I have jacobs parts in there as well. Is there a simple way to check voltage to injectors from the DDEC computer? I am probably going to have to take it to a DD service shop to fix the injector. I'd rather not unless someone else has agood idea for me:) Thanks

[NJT 5573]

You may be able to check some continuity. I think if nothing looks loose its probably still something loose. Is it safe to move the wires around with it running? You should know right away if it picks up that cylinder. When you hang an injector in a diesel, it can sound like a rod knocking. I think maybe yours just isn't working.

[homermandy]

Ok, here's the latest. I checked the 4 wires from the DDEC to the injectors. I wasn't sure what I was finding as there is a sort of tandem series of wires as the 1st one enters the rocker area. I checked continuity from each pin of the connector, and it beeped on each terminal in the rocker cover area.  It also beeped from each pin on the connector to all other pins on the connector. Anyways, I got the same coninuity behavior on all 3 injector points. So now I am lost. I'd really like to not bend over and pay probably $500 or so to fix the problem:)

[lloyd]

I would try checking continuity across the two connections on the injector (with the wires off the injector) that is not working, you should have a reading. If there is no reading the soleniod has failed, which means the injector must be replaced. How long of a warrenty did you get when they replaced the injectors?