03 TDI. Low power. Not an easy one

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Losing my shirt on this car. It has almost no power, and literally 0 power above 2500rpm. Won't rev past 3000rpm under load. When revving in neutral, it is sluggish and when it hits 2000rpm it struggles to push through to 3-4000rpm. With MAF unplugged, the engine will not rev above 2000rpm in neutral, and smokes like crazy (getting fuel, obviously).

Have removed all intake and exhaust parts, no restrictions. Turbo works perfectly. Boosts to spec. MAF spikes around 600 at 2200rpm, and drops quickly to 400. Tried known good MAF. 12v, 5v and ground are good on the MAF connector. Compression is 490-500lbs across the board. Tried a used set of injectors, and injection pump. Timing is bang on. Fuel pickup is new, no restrictions to the fuel filter. Air and fuel filters are new, no snow screen. Valve train is intact and looks good.

I'm out of idea's, besides a weird fluky ECU issue or an internal mechanical problem of some sort.

No trouble codes, and boosts to spec.

Hopefully someone has an idea or can spot something i've over looked, before I put an engine in this car!
 

jimbote

Certified Volkswagen Nut
Joined
Jul 10, 2006
Location
spiral arm, milky way (aka central NC)
TDI
Tacoma 4x4 converted to TDI
watch your maf and your requested vs actual boost while driving.... requested vs actual should be spot on .... if the maf readings flatline just after the power drops off then you probably have a clogged cat if it flatlines about the same time then the intake is prob clogged (already eliminated) .... i see you've already eliminated the exhaust as a restriction.... can you post maf/boost logs ?
 
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AnotherPerson

Veteran Member
Joined
Oct 24, 2015
Location
New Orleans
TDI
1999 Beetle
I would second a exhaust restriction if your showing proper boost. My cat was pretty jammed up at 245k miles. Made a nice thump when it fell off.


Sent from my iPhone using Tapatalk
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
No intake or exhaust restrictions, what so ever.

Boost will stay as requested.. MAF falls to 350-400 shortly after 2000rpm. Boost is still there at this time.
 
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Rembrant

Veteran Member
Joined
Oct 31, 2014
Location
Canada's Ocean Playground
TDI
2013 Golf TDI DSG
No intake or exhaust restrictions, what so ever.

Boost will stay as requested.. MAF falls to 350-400 shortly after 2000rpm. Boost is still there at this time.
I'd be investigating the MAF and/or MAF connections. If you're able to hit 3000 RPM and full boost, your MAF specified and actual should peak way up around 800-850 or so, not 600.

Like Jimbote suggested above...what is the MAF specified vs actual?
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
MAF specified is normal. 875 or something. Actual, hits no more than 640 briefly, and the power cuts off at this time.

The MAF on this car currently, is the MAF i took off of my daily driver. Known good part.

Feels like intake/exhaust restriction but i've double checked it all. Had the intake and front pipe off, nothing going on there.
 

Rembrant

Veteran Member
Joined
Oct 31, 2014
Location
Canada's Ocean Playground
TDI
2013 Golf TDI DSG
The MAF on this car currently, is the MAF i took off of my daily driver. Known good part.
Did you test the MAF in the other car to make sure it actually hits 800 or 900, etc?

Is your EGR valve still intact? Are you sure it's closing?

Check for leaks between the MAF and turbo inlet?
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
If you're not getting 850 or more then you have a MAF issue.

In general, if you cannot readily hit redline while in neutral it's going to be the MAF. And, of course, under load your Actual should always be able to meet your Requested.

If you cannot swap the MAF into another car to verify performance then start checking your MAF's wiring (connectors have been known to cause problems- I'll hit them with an electrical contact cleaner and then dab with dialectic grease).

Where did this MAF come from?
 

keaton85

Veteran Member
Joined
Feb 26, 2011
Location
Camden, ME
TDI
Golf MK4
Have you run a boost graph with VCDS? Check VNT movement? Redone the vac lines? Check for cracks in the large brake booster hard line?

There are tons of topics on limp mode, it seems like you have only covered a fraction of the common issue areas. Leaving out the critical ones...
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
This is not limp mode. There are no codes. This is constant low power and struggles to rev up in neutral.

The MAF came out of my daily driver. Works perfectly. Turbo and actuator working perfectly. The EGR is closing, and I've tried with it unplugged, no change.

MAF connector looked great, and I have had it unplugged + reconnected numerous times, but will try cleaning for the heck of it.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
This is not limp mode. There are no codes. This is constant low power and struggles to rev up in neutral.

The MAF came out of my daily driver. Works perfectly. Turbo and actuator working perfectly. The EGR is closing, and I've tried with it unplugged, no change.

MAF connector looked great, and I have had it unplugged + reconnected numerous times, but will try cleaning for the heck of it.
Are you able to rev up in neutral w/o the MAF connected?

Did you look at each pin in the connector? Check that each wire is seated?
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Connector looks good, clean, each wire is where it needs to be.

With the MAF unplugged, data does default to 550 and the car will not rev above 2000rpm in neutral. Smokes and stutters like crazy. With MAF plugged in, it hits what feels like a "restriction" at 2000rpm and struggles to climb to 3000rpm+.
 

dogdots

Vendor
Joined
Sep 4, 2002
Location
Kansas City
TDI
None
Which timing is "bang on?" Static or VCDS? When connecting to VCDS and selecting "tdi timing" button does the engine sound change at all? If it does, you have electronic control of timing that is lost when connecting through VCDS indicating mechanical timing is far enough out that the ECU is reeling it back in.

Is this a 5 speed or auto car?
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Physical timing is good. Was double checked when I replaced the pump. Dynamic timing at the top of the spec, advanced.

5 Spd car.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Yours sounds like the same scenario I went through. You replaced your pump--The IP, right? Although this may sound crazy, have you checked the output of your IP? I ask because I did not until after I replaced my pump and the pump was not the problem; the problem was the pickup in the tank.I did apply vacuum to the pump input and got fuel and was sure it wasn't the fuel pickup...
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Not sure how to check the output of the pump. The sending unit in the tank is new. Very clean. Car is slow to rev right from idle, so I think it's more than a fuel supply issue. I tried an ECU for ****s and giggles, and that wasn't it either.
 

Rembrant

Veteran Member
Joined
Oct 31, 2014
Location
Canada's Ocean Playground
TDI
2013 Golf TDI DSG
Car is slow to rev right from idle, so I think it's more than a fuel supply issue. I tried an ECU for ****s and giggles, and that wasn't it either.
Well, ECU is ruled out, so that's good. As you reported earlier, your MAF numbers are barely lifting off idle specs, so the engine will be a dog for sure. No air, no fuel, no power.

I've not personally tried this, but I've read where guys have used a shop-vac to test the MAF.
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
What's the boost numbers you are hitting? Are you 100% sure the timing belt is on correctly?
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Fuel looks/smells good. This has been a consistent problem over at least 5 tanks of fuel.

The car boosts to spec, or just under. 1800-1900mbar. The timing is perfect.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
Before removing the head examine the timing belt to see if its missing teeth, or not timed correctly?
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Fella's, read the thread. I'm not new here. Timing belt was re+re'd with pump replacement. Timing was also checked before this.

And no, I did not replace the engine due to a clogged intake manifold.
 

USMCShooter

Active member
Joined
Mar 17, 2016
Location
Pensacola, FL
TDI
'98 Jetta ALH, 99.5 Jetta ALH
I'm wondering if maybe the camshaft timing slipped somehow within the sprocket itself....I'd be curious to put the camshaft block in and see what the marks look like...this sounds like cam timing severely retarded to me....slow to accelerate and low power from off idle, with everything you've tested electronically, sounds like a mechanical timing issue to me...
 
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