Are these things normal?

[westyss]

My 2007 FG manual states to use the exhaust brake when you want to increase braking and not to have it on all the time because it might inadvertently be engaged while driving which has happened a few times to me on the highways, not so good for fuel economy I guess? so I leave it off as the manual states and start the deceleration process then flick it on for the rest of the time.

 

[ajamesr]

So it got worse.... The smoking that is. It used to just be when it started up until warm, but because of that, I wasn't all that worried, it wasn't too bad. So I set out on a road trip, and got about 400 miles in, when it changed. Now any time I accelerate over 2300 RPM it just starts dumping smoke out the tail pipe.

The smoke is gray/white and smells like diesel. My coolant and oil levels have not gone down, so I know they aren't the cause of smoke. This looks and smells just like the smoke my shop heater puts out, right before it ignites. So I'm pretty sure it's from unburned diesel.

What would cause this to happen only when the RPM's are high? It's not that it gradually gets more and more, it goes from no smoke at all to tons of smoke almost instantly once you hit the RPM line. Is this a compression issue, or an injector, or something else?

Also how safe am I to drive it? I'm over 100 mile from the nearest city with any repair shops, do I need to have it towed or can I drive it slowly there? It still seems to run great, no lack of power, no problems starting up. If it wasn't for the smoke, I would have no idea anything was wrong.

Thank you all again.
(and please don't remind me how stupid I am for taking a trip before getting it fixed, I already know)

 

[SkiFreak]

I am no diesel mechanic, but this sounds very much like a fuel issue.
Check your fuel filter, to ensure it is not blocked.
When it starts to smoke, does the engine noise increase as well? It could be dirty/faulty injectors.

 

[ajamesr]

I am no diesel mechanic, but this sounds very much like a fuel issue.
Check your fuel filter, to ensure it is not blocked.
When it starts to smoke, does the engine noise increase as well? It could be dirty/faulty injectors.

The smoke starts around 2300 RPM, the noise doesn't start until 2800, but after paying attention, I'm not sure there is a "noise" I think it may just be the normal engine sound, just at the RPM is when it's loud enough, that the sound really starts coming into the cab.

 

[SkiFreak]

Any decent diesel mechanic could probably do an assessment for you, it would not have to go to a dealership.
As I said... it sounds like a fuel issue.

 

[kerry]

I suspect the wastegate on your turbo is blowing off at 2300 rpm’s decreasing air flow and increasing smoke. I’d try wiring your wastegate closed and seeing if it solves the problem.

 

[ajamesr]

I suspect the wastegate on your turbo is blowing off at 2300 rpm’s decreasing air flow and increasing smoke. I’d try wiring your wastegate closed and seeing if it solves the problem.

Unfortunately my truck doesn't have a turbo, the 4d33 is naturally aspirated. That would be a good idea though.

 

[ajamesr]

Im not sure if I should start a new thread or kee going with this one, but...

Has anyone ever timed a injection pump?

After countless hours of reading and researching, I finally found a method to do it on this engine:
1:Remove the valve from the #1 fuel line
2:Rotate engine to about 30° TDC compression stroke
3: pump fuel manually while slowly rotating engine.
4:When the fuel stops coming out of the #1 fuel line, check marks and that's where you're timing is.
(I couldn't find an exact number of where it should be, but other similar engines were between 7-10)

So I did all that, but here is my problem: the fuel never stopped coming out. I slowly rotated it 720° (two full rotations incase I wasn't on compression stroke) and it never stopped flowing.

Does this mean I'm doing it wrong, or does it mean whatever kind of plunger is supposed to stop it at a certain time isn't doing it's job? If that's the case, it would sure explain the unburned fuel if it's always pumping.

I'm so lost here, please help.

 

[SkiFreak]

It can be good figuring out stuff yourself, but there are times when outsourcing is advised.
As I said before... contact a diesel mechanic and discuss your issues.

 

[yabanja]

Im not sure if I should start a new thread or kee going with this one, but...

Has anyone ever timed a injection pump?

After countless hours of reading and researching, I finally found a method to do it on this engine:
1:Remove the valve from the #1 fuel line
2:Rotate engine to about 30° TDC compression stroke
3: pump fuel manually while slowly rotating engine.
4:When the fuel stops coming out of the #1 fuel line, check marks and that's where you're timing is.
(I couldn't find an exact number of where it should be, but other similar engines were between 7-10)

So I did all that, but here is my problem: the fuel never stopped coming out. I slowly rotated it 720° (two full rotations incase I wasn't on compression stroke) and it never stopped flowing.

Does this mean I'm doing it wrong, or does it mean whatever kind of plunger is supposed to stop it at a certain time isn't doing it's job? If that's the case, it would sure explain the unburned fuel if it's always pumping.

I'm so lost here, please help.

The excessive smoking is likely over fueling. This rules out fuel filter and tank issues. Likely related to the injection pump as you have surmised. The description you have given of the 720 degree rotation indicates to me that you may have a bad injection pump(not my area of expertise). There is a real possibility of an engine runaway where the engine just keep running and running and you have to use the emergency shutoff to keep it from over revving and causing complete engine failure. I would probably try to limp it to the nearest town (most rural towns have a diesel mechanic due to logging or farming operations) while keeping it below 2300 rpms and being ready to use the emergency shutoff button at a moment's notice.

Allan

 

[Zuber]

Could this be a simple as a clogged/bad air filter? I'm assuming you've checked it.
Without a turbo, this engine will be starved for air at higher rpm's anyway. I wonder if it has a pump from a turbo motor? That would have a fuel curve that would put out a lot more at higher rpm's.
Probably just wear in the pump like everyone else thinks.

 

[kerry]

I believe the fuel should stop. I don’t understand how it can continue

 

[kerry]

I’d post your problem on the diesel forum at PeachParts.com. It’s a Mercedes diesel forum but a lot of good dieselheads there who know a lot about older NA diesels. Tell them I sent you. I used to be a regular there.