I will paypal $100 to the first person who can tell me how to fix my car.

diesel_smoke

Veteran Member
Joined
Mar 3, 2005
Location
Indiana
TDI
Jetta, 2001, Deep Blue
If replaced any vacuum hoses, could one be collapsing causing restriction with a good hose?

I don’t know much about the rev limiter but could this be set wrong or faulty? How to check??

How sure are you the MAF connection is making sure contact. Prongs do spread out with multiple plug in’s and outs.

Good luck.
 

Fortuna Wolf

Veteran Member
Joined
Apr 28, 2006
Location
Wilmington, NC
TDI
2002 Jetta TDI Auto Sedan
The VNT adjustment nut came lose and worked its way off, so the VNT barely moves now at full vacuum!

(you've got me, dunno what the heck is wrong)
 

Herm TDI

Vendor
Joined
Nov 21, 2001
Location
Richmond, Maine...The far side of Witsend
TDI
2002 Golf GLS Malone Stage 3, P+520 nozzles, 11MM Inj pump, Sachs VR6 clutch, Stelth Race Pipe, Immo Deleat, EGR Deleat
veget8 said:
... so if it is a restriction, it still could be on either side of the turbo.

So we're down to the following possibilities if it's air related:
1. Restriction in the intake path (but where? intercooler; intake ports on head)
I say the restriction is likely deep in the thorat of the intake manifold AND the #2 & #3 intake passages of the cylinder head.
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
Thanks everyone for all your suggestions! I am still working on this... So far nothing has worked. Looks like I'll be pulling the intake manifold off again as soon as I get a chance.
 

Fortuna Wolf

Veteran Member
Joined
Apr 28, 2006
Location
Wilmington, NC
TDI
2002 Jetta TDI Auto Sedan
How thorough were you when cleaning the intake last time? Make sure to get an inspection mirror. Might be able to attach a chopstick to a vacuum cleaner so you can scrape the ports safely.
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
FW-
Sounds good. I think this is the next thing I have to check. Thanks for the chopstick suggestion- I'll have to rig something up.
 

rmarkw

Veteran Member
Joined
Mar 16, 2004
Location
Central KY
TDI
Beetle, 2000, Blue
Throttle Position (TP) sensor -G79. What if the TP sensor isn't reading properly? What if at a certain point in acceleration the sensor reads poorly and never reads Wide Open Throttle (WOT)? It's an easy and quick check with Vag-Com, I think under measuring blocks group 2, when the accelerator is depressed output should go from 0 to 100%.
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
Sorry I have been MIA for a little while.

I have my intake manifold off and I took some photos of the ports, which I will post shortly. At first glance I didn't see anything too bad, but I shoved a stick in there and felt some serious thick gook, deep down in.

It's so thick and down in there that I have no idea how I'm going to get it out, right now. I am going to do some searches on this but I just wanted to get a status update on here ASAP.

Thanks
-Scott
 

Herm TDI

Vendor
Joined
Nov 21, 2001
Location
Richmond, Maine...The far side of Witsend
TDI
2002 Golf GLS Malone Stage 3, P+520 nozzles, 11MM Inj pump, Sachs VR6 clutch, Stelth Race Pipe, Immo Deleat, EGR Deleat
Herm TDI said:
I say the restriction is likely deep in the thorat of the intake manifold AND the #2 & #3 intake passages of the cylinder head.
veget8 said:
I have my intake manifold off and I took some photos of the ports, which I will post shortly. At first glance I didn't see anything too bad, but I shoved a stick in there and felt some serious thick gook, deep down in.

It's so thick and down in there that I have no idea how I'm going to get it out, right now. I am going to do some searches on this but I just wanted to get a status update on here ASAP.

Thanks
-Scott
Scott,
How I clean these type of deposits is to soak the whole intake manifold in diesel fuel (over-night with a really clogged intake). Then I take it to my local car wash and use the pressure washer to blast out the blockage.

You will also have to inspect and clean the intake ports of the cylinder head. Just make sure that your intake valves are closed befor you do any poking, scraping.
I clean on port at a time and then rotate the engine to close the next intake valve and continue in this manner untill I have all 4 intake ports clean.
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
Herm- How do you clean the inside of the cylinder head ports effectively? It's definitely coated with sludge, but if there is a blockage, it appears to be pretty deep down (really hard to see). What kind of implement do you use, and how persistant should I be about trying to get it clean?
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
And now... The long awaited conclusion of this thread

Here's what I've been doing:

1. I removed the intake manifold and valve cover, rotated the engine through until the #1 intake port was closed, sprayed a multipurpose household degreaser called "Greased Lightning" into the port,

2. scrubbed way down inside with a bottle brush.

3. Also shoved a screwdriver around to scrape the difficult junk. It felt mushy. I cleaned the screwdriver with a paper towel after each removal.

4. Then I shoved paper towels down into it to try to absorb the cleaner, and

5. finally stuck a vacuum in front of the port to attempt to remove any loose debris. This last step didn't feel like it did much, but it was worth a try.

I repeated this procedure for all of the ports. The #3 port definitely felt more mushy than the 1st and 2nd, and the 4th one was pretty bad too. I have no idea how I would have scientifically determined the actual amount of blockage in each port. Buttoned it all back up and started it. It idled "funny" for a while and then straightened out (possible it was passing a little bit of the cleaner through. Probably not great).

Took it for a test drive. Car now has pretty persistent power all the way through the RPM range, even past 4000 rpm. Turbo spooling is a little faster, low end power is slightly more responsive. I haven't had a chance to take it for a drive on the interstate yet, but I'm fairly confident about saying "case closed" at this point.

HermTDI is the winner. This was the 3rd response to the original posting I received and specifically addressed the port blockages. Thanks Herm- you have a PM.


Herm TDI said:
You mentioned that you cleaned the intake manifold assembly.

Did you also clean the air inlet passages in the cylinder head? I had an A-3 come to me after it had been in the hands of a "stealership" for a persistent low power problem.

I removed the intake manifold and found #3 air inlet passage about 90% blocked/ clogged and #4 air inlet passage was more then 50% blocked.
To everyone else who spent time thinking, pouring over photos, plots, data, and offered suggestions- I wish I had enough money to send you each $100. My gratitude is beyond words for your trying helping a friend in need. I look forward to hopefully meeting some of you at a future get together, perhaps.
 

Herm TDI

Vendor
Joined
Nov 21, 2001
Location
Richmond, Maine...The far side of Witsend
TDI
2002 Golf GLS Malone Stage 3, P+520 nozzles, 11MM Inj pump, Sachs VR6 clutch, Stelth Race Pipe, Immo Deleat, EGR Deleat
Last edited:

Herm TDI

Vendor
Joined
Nov 21, 2001
Location
Richmond, Maine...The far side of Witsend
TDI
2002 Golf GLS Malone Stage 3, P+520 nozzles, 11MM Inj pump, Sachs VR6 clutch, Stelth Race Pipe, Immo Deleat, EGR Deleat
veget8 said:
Herm- How do you clean the inside of the cylinder head ports effectively? It's definitely coated with sludge, but if there is a blockage, it appears to be pretty deep down (really hard to see). What kind of implement do you use, and how persistant should I be about trying to get it clean?
The procedure that I use is reather straight forward.
Once I verifi that the intake valve is closed I use an old 12" long straight slot screw-driver (thin one) and bent into a arch about 3" from the tip. I use this "tool" to gently probe the intake port. I then use a bl;ast of compressed air to clear away any loose debris. I continue "probing" and air blasting untill I have the port clear. No not get in a rush or do any hard poking...take your time and you'll end up with a pretty clear intake port. The most important issue is making sure that the intake vale is closed during your cleaning/air blasting.
 

veget8

Veteran Member
Joined
Aug 9, 2002
Location
Randolph, VT
TDI
Golf, 2002, Silver
Herm TDI said:
Insted of sending me the $...please split the differance.

Send $50 to Fred in support of this web site. (Use the donations link at the chat room).
http://tdiclub.com/chat/

Send $50 to the Maine Special Olympics
http://www.specialolympicsmaine.org/

Thank you,
Herm
The money has been sent according to your wishes. A very admirable choice. Thanks again
-Scott
 

Hoffer

Veteran Member
Joined
Mar 3, 2003
Location
Pittsburgh, PA
TDI
Golf GLS, 2003, Black
veget8 said:
HermTDI is the winner. This was the 3rd response to the original posting I received and specifically addressed the port blockages.
Nuts. I definitely have some sort of intake blockage post turbo. Here's the graph:



I've found an excellent place to do the uphill third gear run. I had this thing floored for quite some time. Whatever the timestamp value is, it was about 80 of those.

Have no problem meeting requested boost. But airflow is seriously restricted. The car has trouble getting out of its own way up a hill. It has near normal responses below 2500 RPM.

The funny thing is that little overboost. When revving from a lower starting point I can actually feel the power drop when I hit that overboost. I'm guessing some restriction is causing the turbo to be able to spool up quicker and not deliver as much volume.

I had the intake off several months ago and cleaned it out. Put in the DG Racepipe as I didn't want to have to do that again. Looks like I may have to. Only other possability would be the intercooler, I suppose.

There is a fresh MAF in the vehicle (the previous one may have been giving me dead spots, or it could've been this). If "D.cycle MAP v." is the N75, then for most of the run it's at ~52%. It shot up to a whopping 65% right when I hit the overboost, but then backed off for the rest of the run.

I don't know if I could get a graph to be any more indicative of the problem. Good times. At least with EGR delete, the manifold is much easier to take off.

And I was wondering why the computer wasn't throwing any EGR codes... :cool:
 

rmidgett

Well-known member
Joined
Feb 10, 2012
Location
Nashville
TDI
2001 Jetta GLS
Insted of sending me the $...please split the differance.

Send $50 to Fred in support of this web site. (Use the donations link at the chat room).
http://tdiclub.com/chat/http://www.paypal.com/cgi-bin/webscr

Send $50 to the Maine Special Olympics
http://www.specialolympicsmaine.org/

Thank you,
Herm
How should the engine be rotated over slowly to allow the intake valves to be closed on each cylinder one by one for this process? Perhaps a long breaker bar with a socket on the bolt of the crankshaft pully?
 

miningman

Veteran Member
Joined
Sep 3, 2007
Location
alberta
TDI
2003 Golf
Sounds as if the most valuable lesson is if you are running a tdi , post Veggie status , pull ( or swap) the cylinder head. mucho cleaning effort and re evaluate
 

tgray

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Joined
Sep 12, 2004
Location
Marengo, IL
TDI
'02 Beetle, '05 Golf, 2000 Jetta, 2001 Jetta, 2002 Jetta
Take a good look at your MAF readings. Something seems strange as it is not delivering what it is calling for. If the computer doesn't read things right it doesn't run right. The computer will starve it of fuel and boost to protect the engine. The terminals at the MAF in these cars are known to go bad. There was write ups years ago about putting oil on the terminals to keep the corrosion down.
I had a gas new beetle that was stalling down the road for no reason. The code said throttle position sensor but a new one did nothing. Testing the wires seemed a little bit strange with the voltages so I cut the plug off and properly soldered in a new plug. Problem solved. I have parted out cars and found the ECU plug corroded on a wire at the connection. I am not saying for sure it is your wire connections but you should start with what you know is not right and then go from there.
- If unplugging the MAF completely and the car still will not run fairly good, then something else is wrong. You will not get full power but it should run ok to drive. Nothing like what you are describing. These cars are fairly simple and can run fairly well with a lot of stuff unplugged just to eliminate it out of the equation.
- If that doesn't work, then carefully check your vacuum hose connections. A crossed hose can do weird things. Make sure your breather hose on the N75 is not plugged. (the one that plugs into the air cleaner.) I have seen people put plugs in this hose and wonder why it doesn't run right.
It seems you are going into limp mode. Did you verify this? Limp mode will only turn off by restarting the engine.

Did you try running the car off a hose into a can and eliminate the fuel line to the tank as being plugged?
 

tgray

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Joined
Sep 12, 2004
Location
Marengo, IL
TDI
'02 Beetle, '05 Golf, 2000 Jetta, 2001 Jetta, 2002 Jetta
I knew my eyes were going bad and now it is confirmed. I always forget to look at the date.
 

Poor King

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May 20, 2020
Location
NY
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'91 Jetta, '91 GTI, '04 Touareg
I just went to the first page on this sub-forum and there are non-viewable threads from 1969.
 
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