Car won't go above 25 mph or 3400 RPM in park - If I can't fix it I will need to get rid of it!

2002_auto_tdi

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Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
Is the intake coked up after the EGR? It might not be getting enough air.
Your post on the throttle position and IP correlating. How do I do that?

Also, the intake was never that bad to begin with. While replacing the turbo, I oven cleaned and pressure washed it multiple times for good measure. It is not "light on fire" clean but still very clean.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
If the actuator moves then there is vacuum. Does it go all the way to the stop or only move slightly? It should go all the way to the stop screw. You should also see the charge air pressure change on that screen. If it does then the N75 is working and so is the actuator. Let's assume that passes.

Question: You said you replaced the EGR valve? Where'd you get it? Unplug the vacuum hose to it and stick a golf tee in the hose (plug it.) That should throw a code rather quickly (the ECU, when it cycles that, expects the MAF to drop and if it doesn't it trips a code) but eliminate a stuck-open EGR solenoid that is slamming the valve open (which can drown the intake with exhaust that has no oxygen in it.) No fire, no pressure, doesn't matter where the vanes are you get no power.

I'm suspicious of that valve (and possibly the control solenoid) for this reason:
Note: The strangest thing is happening. After revving the car up, I can hear a thunking noise from inside the EGR/ASV. If I pull the vacuum line to the unit, the sound stops. The engine pulses slightly with that sound as well and doesn't run as well at idle. I did recently change out the EGR/ASV with a Chinesium unit as it was blowing oil out of the weep hole around the time that all of this happened.
I'm ignoring the possibility of the intake being plugged beyond the EGR because you said that was cleaned -- and I've seen intakes with BIC pen size holes in the sludge and the cars could still make boost, surprisingly enough.

If you completely run out of other possibilities the cat may have collapsed internally and is blocking exhaust flow. But I hate going there without running out of other possibilities first since if you're wrong on that one you just bought something that isn't broken.
 

2002_auto_tdi

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Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
If the actuator moves then there is vacuum. Does it go all the way to the stop or only move slightly? It should go all the way to the stop screw. You should also see the charge air pressure change on that screen. If it does then the N75 is working and so is the actuator. Let's assume that passes.

Question: You said you replaced the EGR valve? Where'd you get it? Unplug the vacuum hose to it and stick a golf tee in the hose (plug it.) That should throw a code rather quickly (the ECU, when it cycles that, expects the MAF to drop and if it doesn't it trips a code) but eliminate a stuck-open EGR solenoid that is slamming the valve open (which can drown the intake with exhaust that has no oxygen in it.) No fire, no pressure, doesn't matter where the vanes are you get no power.

I'm ignoring the possibility of the intake being plugged beyond the EGR because you said that was cleaned -- and I've seen intakes with BIC pen size holes in the sludge and the cars could still make boost, surprisingly enough.

If you completely run out of other possibilities the cat may have collapsed internally and is blocking exhaust flow. But I hate going there without running out of other possibilities first since if you're wrong on that one you just bought something that isn't broken.
It goes all the way to the stop. I will review again, but as you mentioned let's see if that passes.

The EGR was Amazon/Chinesium.

I will try the EGR test.

As far as the cat test, could I just disconnect the 3 nuts to the down pipe and rev it? The nuts really can't take much more removal and reinsertion without stripping out but suppose that I could try that.
 

vandermic07

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Joined
Jun 5, 2011
Location
West Central Pennsylvania
TDI
01 Golf 5 spd, 03 Jetta Wagon
Sorry, I didn't remember you saying that the intake was clean.
I never thought about the CAT. Definitely worth a try.

As for Throttle position test, I know you can check throttle position in VDCS but I'm not sure if it monitors the IP position as well. I was hoping someone else would chime in to see if there is a possibility there.
 

2002_auto_tdi

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Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
Sorry, I didn't remember you saying that the intake was clean.
I never thought about the CAT. Definitely worth a try.

As for Throttle position test, I know you can check throttle position in VDCS but I'm not sure if it monitors the IP position as well. I was hoping someone else would chime in to see if there is a possibility there.
It's alright. I might not have mentioned it. Thread is getting long, lol.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
When was the EGR valve replaced? Before or after the car lost power? I hate CRAP (Chinese replacement auto parts) with a white-hot passion -- and with good cause. Got a block-off plate (and a new EGR gasket afterward) handy?

Vander, I don't think that's it although its POSSIBLE the IP is boogered. I say "unlikely" because the fault precedes the replacement, it did not occur when the replacement was made.

It now appears we know:

1. The actuator works.
2. The N75 works; when cycled in Basic Settings it runs the full range. (What's the boost, actual do when it cycles?)
3. There remains insufficient oxygen or insufficient fuel, ergo, no power -- but the fault occurred before the IP was replaced, which tends to implicate oxygen, not fuel.

What you got left, reasonably, is that the intake is being polluted with exhaust (EGR wide open irrespective of drive to the valve) which means there is no pressure to spin the wheel and make boost (no matter where the vanes are) or the exhaust is plugged and thus what IS there can't get out, scavenging is for crap and again you make no power.

In either case the ECU will not inject fuel it doesn't believe it can burn (from the MAF sensor.) No airflow, no fuel.
 
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2002_auto_tdi

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Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
When was the EGR valve replaced? Before or after the car lost power? I hate CRAP (Chinese replacement auto parts) with a white-hot passion -- and with good cause. Got a block-off plate (and a new EGR gasket afterward) handy?

Vander, I don't think that's it although its POSSIBLE the IP is boogered. I say "unlikely" because the fault precedes the replacement, it did not occur when the replacement was made.

It now appears we know:

1. The actuator works.
2. The N75 works; when cycled in Basic Settings it runs the full range. (What's the boost, actual do when it cycles?)
3. There remains insufficient oxygen or insufficient fuel, ergo, no power -- but the fault occurred before the IP was replaced, which tends to implicate oxygen, not fuel.

What you got left, reasonably, is that the intake is being polluted with exhaust (EGR wide open irrespective of drive to the valve) which means there is no pressure to spin the wheel and make boost (no matter where the vanes are) or the exhaust is plugged and thus what IS there can't get out, scavenging is for crap and again you make no power.

In either case the ECU will not inject fuel it doesn't believe it can burn (from the MAP sensor.)
Yeah, I resisted doing the blockoff since this is an auto.

I don't think the EGR is at fault since it is closed until the first failure then it starts hopping up and down *OR* does it open up right when it won't rev past XX rpm??

Hmmm... I think I will pull and have someone watch to see if it opens right at that moment. EDIT: EGR does not open after vacuum is disconnected so I think we can rule that out. I just find the synchronous moving in and out of plunger awfully weird after the failed rev to redline with vacuum applied.

I understand the Chinese knockoff stuff. The fault does precede the replacement of the EGR.
 
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PakProtector

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Jan 5, 2014
Location
AnnArbor, MI
TDI
Mk.4's and the Cummins
Pak, he has a 10mm pump with auto nozzles; that thing is a lawn mower without boost, and by his data he has no boost despite the ECU asking for boost.

My money at this point, given the above diags (known good vacuum at the input to the N75 and actuator works when vacuum is applied to the hose at the N75 heading to it) my bet is that the N75 is not working, either electrically or it is mechanically jammed/plugged closed.

There may be other problems too but eliminate that which you can without spending money first.
The 10mm pump is quite capable of driving enough fuel to get to redline. Even with smaller than auto injectors. IFF the pump is good, the change shifted the timing significantly. NA tdi's whilst slow are not having issues getting to redline unloaded.
cheers,
Douglas
 

2002_auto_tdi

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Aug 3, 2020
Location
Virginia
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03 5spd wagon and 02 01m sedan
Unbelievable! I assume bad cat then? I went for a drive to fill it up after all of this mess and it drove great for a 10mm pump and an 01M anyways.

I have not taken a vehicle to a muffler shop in decades for fear of them jacking something up. Suggestions? I really don't think it makes sense to go performance exhaust on an 01M. As a matter of fact, I should probably be thankful in a round about way for the 10mm downgrade.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Yep - collapsed and packed cat.

Not that hard to R&R; the replacements are from the flange (so including the flex) to behind the cat. The part (third-party) is about $300. Plenty of people have cut it out and straight-piped it but I recommend against that. You could also go the "ghetto" route, remove it and rod it, basically breaking it up and dumping it out. It then LOOKS like it has a cat but doesn't. Recommend against that too. Both make for a fairly loud car too, even with the muffler and obviously if you get tailpipe sniffed on an inspection you fail.
 

2002_auto_tdi

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Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
Yep - collapsed and packed cat.

Not that hard to R&R; the replacements are from the flange (so including the flex) to behind the cat. The part (third-party) is about $300. Plenty of people have cut it out and straight-piped it but I recommend against that. You could also go the "ghetto" route, remove it and rod it, basically breaking it up and dumping it out. It then LOOKS like it has a cat but doesn't. Recommend against that too. Both make for a fairly loud car too, even with the muffler and obviously if you get tailpipe sniffed on an inspection you fail.
Thanks for and everyone else for your perseverance. It is an aftermarket exhaust put on by the guy who sold it to me. We still talk to this say. He got it from Rockauto but was some cheapie to get him by inspection. The cat is not flanged so rodding it might be a bit harder. Off road pipe would save money but wouldn't make sense as a pass on to my kid.

I guess it's off to a muffler shop to get a new cat. Just don't want to end up with something that doesn't flow right. I assume cats cost a small fortune now? Maybe I should take the one from my Prius before someone else does. J/K.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Naw, the "replacement" setup is the flange back to a flare behind the cat. $300 or so for an off-brand one, but it's a real cat for a TDI, not a bypass, and includes the flex section as well.

If you can find "just a cat" then it's pipework which isn't that bad.
 

Tdijarhead

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Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
Great job in tracking this down. Idparts has the entire system, including a new cat, and with all the experience you now have this would be a walk in the park to install yourself.

 

Zak99b5

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Apr 30, 2021
Location
Albany NY
TDI
2003 Jetta TDI
I just installed the IDParts $400 complete exhaust. It's aluminized steel, so we will see how many Upstate NY winters it will last (I'm putting the over/under at 3; place your bets).

If I hadn't spent quite a bit of money already getting the car in shape since I bought it in May (new fenders, radiator, used IP, timing belt kit, wheels, tires, suspension, headlights, a/c clutch, fuel filter, coolant GPs, ps hose, fluids, &c.), I would've bought a stainless DP w/ cat and straight-piped it with stainless. But the CFO wouldn't have it. And for $400 including dp w/ cat, I think it's a great option.
 

PakProtector

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Jan 5, 2014
Location
AnnArbor, MI
TDI
Mk.4's and the Cummins
The only question I keep coming up with is, 'why is the original plugged?' Just not liking the idea of replacing and then having it come to grief too...but that is perhaps for another post.
cheers,
Douglas
 

2002_auto_tdi

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Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
The only question I keep coming up with is, 'why is the original plugged?' Just not liking the idea of replacing and then having it come to grief too...but that is perhaps for another post.
cheers,
Douglas
This was a thought that I had in the back of my mind!!

Only 177k on this car.
 

PakProtector

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Jan 5, 2014
Location
AnnArbor, MI
TDI
Mk.4's and the Cummins
Upstate NY and northern PA are brutal on cars. Rust, rust rust.
So is Michigan...D-Oh! So I shop for these in the south.My '04 from Florida, son's from Atlanta and the '02 from North Carolina. Michigan cars are perhaps good for engine donation... :D

Douglas
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Years ago I bought an A3 Jetta TDI with 34K on it, and the cat was plugged. When the elderly owner took me for a test drive it made sense: he never got the engine over 1500 RPM.
 

2002_auto_tdi

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Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
Years ago I bought an A3 Jetta TDI with 34K on it, and the cat was plugged. When the elderly owner took me for a test drive it made sense: he never got the engine over 1500 RPM.
That is the way that I drive. Makes sense. Not sure about my friend who was the previous owner but I would imagine pretty much the same.

Going to change the transmission mode from Economy to Sport now. I just love the 47mpg on this thing. Makes me greedy! I have the Wagon to be greedy with now though. My son drives like his old man. I kind of like that to keep him safe...but safety is a relative term.
 
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U4ick

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Nov 16, 2014
Location
texas
TDI
2003 jetta tdi
God, I love a happy ending. I can see by gazing into my crystal ball that a lot of fueling and boosting issues in the future are going to get fixed from the knowledge shared in this thread.
 

2002_auto_tdi

Veteran Member
Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
God, I love a happy ending. I can see by gazing into my crystal ball that a lot of fueling and boosting issues in the future are going to get fixed from the knowledge shared in this thread.
Right, so many bases were covered in this one thread. I got pretty dirty on systems that I was afraid of before. This is great.

I must know about 1/3 of the system just based on this one thread.
 
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