Rough idle sometimes and engine surge at low engine speed

Its a 99.5 jetta with about 308k.
With in the last few month I been sometimes getting a little rough idle when the engine is cold. But I would just about always get a engine surge under 2700 rpm while driving. If I give it enough throttle it wont do it. Have never done it on the hwy. Once the engine is at operational temps its fine.
I do have a check eng light on with code p0380. Now that has been on since the beginning of the year. I did find a bad glow plus and replaced it but the check eng light came back with same code. Not really sure this has anything to do with my issue though I could be wrong. Haven't got a chance to hook up the computer to it but was hoping someone might be able to point me in the right direction or a direction. lol

Thank you

Your glow system probably needs a new harness, or "bridge" spliced in. Common, easy, cheap.

That is likely not your driveability problem though.

Could be a few things, injection pump getting some internal wear, injector nozzles less than ideal spray patterns, etc.

I would try some diesel purge or similar and see if that helps. May also want to verify the timing as well as all the temp sensor values when cold before startup.

I would also check for any signs of fuel leakage under the hood at the pump, filter, etc. as you could also have some air leaking in. May also check for any vacuum leaks with the vacuum controls, starting at the booster tube and going out from there. N75 could be sticky, too.

I been using a cleaner for diesel/turbines for the last month. Now I think about it I don't think the problem started until I started using it that I recall. I'll try to check some other stuff today if time and weather permit.

Indwelling said:

I been using a cleaner for diesel/turbines for the last month.

Click to expand...

Did you use the one to add to the tank or the one you run the engine with full strength?

When was the fuel filter changed last?

Scan for the 2 coolant temps mentioned above (gauge and ECU should match) and the fuel temp.

Sorry it took me a while to get back. Been very busy.
Fuel cleaner I use is added to the tank.
The fuel filter is probably over due but I don't think that is the issue.
I forgot to check the temp gauge to the pc. But I did disconnect the CTS and started it with the same results.

Checked the IQ
https://photos.app.goo.gl/sFUpKzCgNNt2XAty6
https://photos.app.goo.gl/sFUpKzCgNNt2XAty6

Still has a rough idle when cold and engine studders when you give it some throttle along with white smoke.

Haven't checked the timing yet.
Anything else I should check?

IQ is Group 000, field 4.
Should read Injection quantity: 11 - 45 = 2.2 - 9.0 mg/stroke

BobnOH said:

IQ is Group 000, field 4.
Should read Injection quantity: 11 - 45 = 2.2 - 9.0 mg/stroke

Click to expand...

Went to group 000 and got random numbers in blocks 1-10.
Escept block 3 was 000.

Indwelling said:

Went to group 000 and got random numbers in blocks 1-10.
Escept block 3 was 000.

Click to expand...

Block 3 is throttle position.
Step on the go pedal.

LOL well that explains that. Where do you find what everything is in the groups?
I use to know a few things long time ago but I forgot most of it now.
I'm thinking some of the problem is gas related. Exhaust smells little different then normal. Going to burn this tank up and refuel at a trusted place and see if that helps.

Indwelling said:

LOL well that explains that. Where do you find what everything is in the groups?
I use to know a few things long time ago but I forgot most of it now.
I'm thinking some of the problem is gas related. Exhaust smells little different then normal. Going to burn this tank up and refuel at a trusted place and see if that helps.

Click to expand...

I think I got it from Ross-Tech. Also a lot from Vortex.
http://www.ross-tech.com/vag-com/cars/vwmkIV.html

Sometimes I think I forgot more then I ever knew.

If you think 'the problem is gas related' then your using the wrong fuel.

wonneber said:

I think I got it from Ross-Tech. Also a lot from Vortex.
http://www.ross-tech.com/vag-com/cars/vwmkIV.html
Sometimes I think I forgot more then I ever knew.
If you think 'the problem is gas related' then your using the wrong fuel.

Click to expand...

Thanks for the info. I should have remembered that.
Lets just say the fuel I got was really cheap.
Got some freash fuel in it now. The idle is a little better but from 1k rpm to 1450 rpm its rough smooths out at 1500.
If I have time today i'll look at a few stuff since I got to replace a headlight thanks to a semi throwing a tire at my car and taking out the light.
The life was driving it btw.
Also lots of white smoke when rev it up to 1k-1500. When back at idle the white smoke stays for a mintue and almost goes away until i rev it again and it repeats. What are the odds of this being turbo related?

Ok checked the timing on the Vag-com and was pretty close to the middle.
Was reading around 44-45. Looks like 48-49 is the target. I might try to adjust the timing above the blue line.

Group 000 feild 4 was around 18 if I remember correctly. Not sure why I didn't record that reading.

Went to group 13 IQ stablilzation
Cylinder #1 .016 mg/str Cy #2 .26 mg/str Cy #3 .05 mg/str Cy #4 -0.49 mg/str
From what I understande these number are good?

The Air mass actual say it should be 230-370 mg/H at idle but it was at 740.0 mg/str

MAF sounds like it's bad.

wonneber said:

MAF sounds like it's bad.

Click to expand...

Its a good place to start.
I'll report back soon as I figured something out or If i get lost lol

Thanks

It turns out to be my MAF sensor.
I disconnected the MAF and it ran fine. Connected it back up and it ran crappy again.
I may leave disconnected until the new one shows up.

Thanks guys

Late update but got the in MAF sensor in and its running great.

Note to anyone that want to try to run their car with the MAF disconnected. It will run. But it runs off a default setting and you will have less power.