2005 mk4 Jetta barely starts

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
I have a 2005 BEW crank no start. Well, it started once, but didn't start well.
Group 13 showed -2.01,-2.01,-1.65,2.99
I checked the timing using the crank lock and pin, replaced the damaged cam position sensor, checked the cam and injector wiring harness (visual inspection) ohmed the injectors out, made sure the asv isn't stuck closed, made sure I'm getting fuel to the tandem pump (didn't check output pressure from the tandem pump yet though)
No codes besides EGR valve (it's deleted, but not tuned) and brake switch implausible signal (possibly LED bulbs)
I also inspected the crank reluctor wheel, as it appears that someone replaced the oil pan recently.
I had gotten this car in this condition In a trade. Trying to get it going now.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
I assume you've done the usual like check batt voltage and that it's cranking fast and strong?
You also mentioned you checked timing at the crank, did you check timing of the cam? With a negative angle that close to zero it should still start, but is odd one is positive almost 5 away.
What about the crank position sensor?
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
I assume you've done the usual like check batt voltage and that it's cranking fast and strong?
You also mentioned you checked timing at the crank, did you check timing of the cam? With a negative angle that close to zero it should still start, but is odd one is positive almost 5 away.
What about the crank position sensor?
Yes, I checked cam and crank timing, using the crank lock and cam pin. The cranking RPM is right at 230-250 or so
Crank position sensor looks good, I didn't ohm it out and verify. I'll plan to scope the waveform on it as well as the cam sensor, as I know that visual inspections don't always catch what's going on.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
Sounds like you're on the right path, only other thing I could suggest is to check injector lash,and I've also heard of those pressed in balls that are in the head near the injector have worked loose in the past, if I remember right they supply oil to the injectors for timing? Can't remember.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
Its been a while... I got it figured out. The injector on cylinder 4 was bad and the fuel system was getting compression in, which was keeping it from firing well.
Replaced the injector and it is running great.
 

Shenandoah

Veteran Member
Joined
Jan 9, 2008
Location
Shenandoah Valley, VA
TDI
2005 Jetta Wagon; 2005 Beetle; 2004 Jetta; 2002 Golf (three of them); 2002 Jetta Wagon; 2000 Audi TT->TDI; 1999 Beetle
Mozambiquer,

Thanks for the information. I have a 2005 New Beetle that developed problems in 2020 with 280,000 miles. It would start and run fine, but as soon as it warmed up it would lose power and act like it was "missing". I could turn it off and turn it on and it would run fine for a couple minutes then start missing again. Then one day, it just wouldn't start. I swapped the Crank Position Sensor, injector harness, fuel filter, etc. No change.

I've always wondered if I had a bad injector? How did you test/determine injector #4 was bad? Thanks.

Eric
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
Mozambiquer,

Thanks for the information. I have a 2005 New Beetle that developed problems in 2020 with 280,000 miles. It would start and run fine, but as soon as it warmed up it would lose power and act like it was "missing". I could turn it off and turn it on and it would run fine for a couple minutes then start missing again. Then one day, it just wouldn't start. I swapped the Crank Position Sensor, injector harness, fuel filter, etc. No change.

I've always wondered if I had a bad injector? How did you test/determine injector #4 was bad? Thanks.

Eric
What I did to determine it was bad is I could see with vcds that it had a misfire on cylinder 4. I checked the cam and checked for continuity on the harness. I had a spare set if injectors so I then swapped one in and it ran a lot better.
Most often its not the injectors, but this car was run on biodiesel and I believe that is part of what killed the injector.
More often the symptoms you describe are a worn cam .
 

Shenandoah

Veteran Member
Joined
Jan 9, 2008
Location
Shenandoah Valley, VA
TDI
2005 Jetta Wagon; 2005 Beetle; 2004 Jetta; 2002 Golf (three of them); 2002 Jetta Wagon; 2000 Audi TT->TDI; 1999 Beetle
Mozambiquer,

Thanks for the quick reply. I'll have to take a close look at the cam again to check for wear. Thanks!

Eric
 
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