Acceleration Hiccup-EGR?

rvamax

Max/2006T1N/140WB/OM647
Hi All,

I have a 2006 T1N, 307k miles, I've had it for almost 40k miles. I have an issue that has persisted since I bought the van, which has proceeded to get worse in the last ~10k miles.

*Quick FYI the transmission was replaced at 292k miles and this issue has remained, so not sure how it could be transmission related.*

The Issue:

When I am slowly accelerating from a standstill or a slow roll, the van will 'hiccup' somewhere between 5-15 mph. If I accelerate a bit faster, the issue is less severe than when I am egg-shelling the accelerator pedal. This hiccup used to only happen on acceleration, now it happens when I am decelerating to a stop. It is generally only one 'hiccup' on accel or decel. Sometimes when I accelerate very quickly, no matter the speed I am driving, I will get black smoke from the tailpipe. Before the engine gets to operating temp, sometimes I will get multiple, less-severe hiccups when accelerating slowly, or going up a hill.

A bit before the transmission went, I pulled the EGR valve which had the black soot, but did not feel like it stuck. I cleaned it with carb cleaner, but don't remember if that did anything for this issue.

The check engine light is not on.

Thank you for any insight! Would like to try and self-diagnose this before I pay a mechanic to.
 

rvamax

Max/2006T1N/140WB/OM647
First stop, air filter, (not using K&N are you???? Second check is MAF sensor,
Had one stumbling just like that yesterday.
A new MAF and a propah air filter fixed it!
Dennis
Hey Dennis! You helped me out with that used transmission a couple of summers back, thank you for your continued help! I've heeded the advice and use only German-made filters, actually just replaced the engine air filter recently.

How would I confirm if the MAF sensor is the culprit?
 

lindenengineering

Well-known member
Hey Dennis! You helped me out with that used transmission a couple of summers back, thank you for your continued help! I've heeded the advice and use only German-made filters, actually just replaced the engine air filter recently.

How would I confirm if the MAF sensor is the culprit?
Hey greetings.
You need to a scan tool on it looking at live data.
First off MG/Hub figures and watch the data output as you enter the "stumble zone".
Dennis
 

rvamax

Max/2006T1N/140WB/OM647
Hey greetings.
You need to a scan tool on it looking at live data.
First off MG/Hub figures and watch the data output as you enter the "stumble zone".
Dennis
I've only got a cheapo code reader, so may not be able to monitor those parameters. Couldn't hurt to try some MAF cleaner before taking it in right?

Thanks again for all of your help.
 

lindenengineering

Well-known member
I've only got a cheapo code reader, so may not be able to monitor those parameters. Couldn't hurt to try some MAF cleaner before taking it in right?

Thanks again for all of your help.
Yes try that first & make the air intake hose to the turbo is in good shape. Any holes or visible cracks can affect how the vehicle performs .
Dennis
 

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