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Intemittent loss of power, heavy smoke - just air in fuel?
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=74714		 Page 1 of 1
Author:  Murmeltier [ Fri Mar 29, 2013 5:34 pm ]
Post subject:  Intemittent loss of power, heavy smoke - just air in fuel?
Hi guys, my '06 crd (109,000 km/67000 miles) is having intermittent and sudden losses of power accompanied by lots of smoke. Sometimes it lasts only a few seconds but other times it lasted a minute or so. No CEL or noise, just gutless and smoky. When not experiencing this problem the engine seems to run fine. I bled off lots of air at the filter head so figured that might be the cause & replaced it with upgraded filter head. Still have a little air to bleed off after the installation and the problem has persisted so may need to look at new fuel lines and lift pump as per other threads. Before I follow up on that, however, I'm wondering what other causes there might be for this intermittent problem. Wouldn't the other issues summarized in the Noob guide (turbo hoses, MAP,) result in steady performance problems, not intermittent? Same for rocker arm wear or timing belt slip--wouldn't those just cause full time problems? The dealer service guy wanted to test injector timing for huge $$ but I said not yet.

I believe it's still air in the fuel that's giving me headaches but suggestions on other things to check would be appreciated.
Author:  Stephen_Jones [ Fri Mar 29, 2013 6:11 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
I am having similar problems with mine (05, 98k miles). I haven't been able to find a solution.
Author:  GreenDieselEngineering [ Fri Mar 29, 2013 6:20 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Most likely the beginnings of EGR system issues. Tuning is a good fix or some parts cleaning/changes, etc.
Author:  flman [ Fri Mar 29, 2013 7:07 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
I would doubt timing would cause an intermittent issue, unless the timing was able to correct itself?
Author:  kjjet [ Fri Mar 29, 2013 10:05 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Murmeltier wrote:
The dealer service guy wanted to test injector timing for huge $$ but I said not yet.

I believe it's still air in the fuel that's giving me headaches but suggestions on other things to check would be appreciated.


These stealerships will tell you anything. Injector timing :ROTFL:

I think your correct. Air is likely your problem. Check all your hose clamps to be sure they are not cutting into the hoses? Filter tight? Bleed, bleed, bleed!

O...ya get a SEGR or a GDE tune asap to stop the EGR. Your engine life depends on it.
Author:  geordi [ Fri Mar 29, 2013 11:28 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Smoke and loss of power equals too much fuel, not enough air or boost.

Smoke is only caused by an excess of fueling, check your boost hoses for holes, but if this is an intermittent-and-fixing-itself kind of problem... Look to the MAP sensor possibly, or certainly the EGR. The stupid EGR might be sticking open, which would allow the boost an EASY path out into the exhaust, while the computer doesn't see the drop at the MAF and cut the fueling to match.

A block off plate and a GDE tune will solve that problem. Might also be a good time to extract the disc from the FCV at the intake elbow. Diesels don't need a throttle plate.
Author:  Hexus [ Sat Mar 30, 2013 6:21 am ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
geordi wrote:
Smoke and loss of power equals too much fuel, not enough air or boost.

Smoke is only caused by an excess of fueling, check your boost hoses for holes, but if this is an intermittent-and-fixing-itself kind of problem... Look to the MAP sensor possibly, or certainly the EGR. The stupid EGR might be sticking open, which would allow the boost an EASY path out into the exhaust, while the computer doesn't see the drop at the MAF and cut the fueling to match.

A block off plate and a GDE tune will solve that problem. Might also be a good time to extract the disc from the FCV at the intake elbow. Diesels don't need a throttle plate.


I concur with Geordi. Check and clean your MAP and MAF sensors. I went into Limp Mode a few times and had black smoke issues when my EGR/FCV were both failing.

It's time for you to get a GDE tune, seriously.

Invest in an hour and the Noob Guide, buy some non-chlorinated brake parts cleaner and clear up the MAP and MAF.

If you aren't going to get a GDE tune, you might seriously want to consider selling it now, as things just get more expensive the longer you wait.
Author:  papaindigo [ Sat Mar 30, 2013 2:30 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Thoughts already posted are helpful and I'll add:
1. unplug the MAF sensor which will throw a CEL but it's harmless. Unplugging the MAF disables the EGR so drive a while that way and see if the problem is gone. If so you definitely need a GDE tune but you really need one anyway.
2. if that doesn't do it get the GDE tune anyway but also try the boost pressure solenoid bypass (viewtopic.php?f=5&t=70602&p=757348&hilit=boost+solenoid#p757348) on the off chance that it's not functioning properly and causing you to lose boost from time to time. If problem goes away replace solenoid (takes like 2 minutes).
3. while you are at it check the turbo van actuator rod to make sure the vanes are not sticky. Per GDE "You can check the vane functionality at idle in park. Underneath the vacuum actuator on the turbo is rod extending downward connected to the vane mechanism. If you pull off the vacuum line at the turbo, the arm should drop about 1/2 inch and then raise back up after reconnecting the vacuum line. It is a bit difficult to see the rod, but this is the easiest method to check for proper VGT vane moevment."

Unless you are going to get to 100,000 miles relatively soon you might consider doing the timing belt job sooner rather than later as your current rubber timing belt is getting on in years if not miles.
Author:  Murmeltier [ Sat Mar 30, 2013 7:52 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Some great suggestions, thank you to all. Proceeding with the GDE tune now rather than later does make sense so that's first up, and in the meantime I'll disable the EGR temporarily as per Papaindigo & give that a test. Then of course the rest of the Noob guide suggestions.

Is unplugging the MAF sensor to disable EGR as straightforward as it sounds? Just plug it back in and EGR function is restored, CEL goes off?

thanks again.
Author:  Hexus [ Sat Mar 30, 2013 7:58 pm ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
Murmeltier wrote:
Some great suggestions, thank you to all. Proceeding with the GDE tune now rather than later does make sense so that's first up, and in the meantime I'll disable the EGR temporarily as per Papaindigo & give that a test. Then of course the rest of the Noob guide suggestions.

Is unplugging the MAF sensor to disable EGR as straightforward as it sounds? Just plug it back in and EGR function is restored, CEL goes off?

thanks again.


Yes, as long as your EGR Valve and FCV valve are functioning properly, the light will go out after a couple minutes of you plugging it back in.

It's right up by the air box.

Make sure you try cleaning that MAP sensor on the intake manifold though, it was causing me to go into Limp mode.
Author:  Auberon [ Sun Mar 31, 2013 12:07 am ]
Post subject:  Re: Intemittent loss of power, heavy smoke - just air in fue
MAP & MAF first ports of call.
You are describing fuel trim issues. As good as the GDE tune is, the sensors still need to be functional for any tune to work as it should.
I have so far learned that what papaindigo said is quite straighforward.
Other adaptive behaviours will not get embedded if it is done as he stated.
Would recommend going down that easy path first before you complicate with block-off plates and tunes although I am not discounting these as ideas for the future.

The next way to go about it is a logical PID analysis. It can needs to be based on logical diagnostics proceures (and the PIDS are grouped so they are a guide) after you have a direction. When you know what is wrong then you can take the quantum leap. papaindigo always suggests a logical process to follow and that is what I am suggesting too.

Don't complicate before you resolve. The old KISS principal.
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