Reving TDI Causes Super Rough Idle/Stall

Monksy

Member
Joined
Jul 12, 2017
Location
London, Ontario
TDI
Mk4
So my TDI still has a hard start, she really doesn't like to get going especially in the winter.
But what I'm trying to figure out is, when I start it up and its idling, if I rev it to red line then let it drop back to idle it will spit and sputter terribly for a second or two and then usually shut off, if it doesn't shut off it will keep sputtering, barely running and I cannot get the rpm's to increase unless I turn it off and restart it.
If it does die right after I rev it, I will not restart for a solid 5-6 seconds of cranking, during which it does not sound at all like the starter is even engaged (which freaked me out the first time), but after those 5-6 seconds it will start to sputter and finally turn on.
I can sit and rev the car no problem to about 3500RPM without having this issue but once I go higher it will cause this.

Any Ideas?
I replaced the fuel filter, fuel return lines going back to the pump from the injectors, checked the injector lines, everything there seems to be ok. I don't know how to check the injector pump, but I did check the pressure release valve on it and its dry so that's not the issue I don't think.
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
Sorry, no good diagnostic for the issue you are having, but how does it generally run after it is started and run/drive "normally"? Where is the injection timing set on the graph? Perhaps it's doing you a favor. I can't imagine any reason or good result from revving an almost cold started engine to high rpm, let alone approaching redline.
 

Monksy

Member
Joined
Jul 12, 2017
Location
London, Ontario
TDI
Mk4
Sorry, no good diagnostic for the issue you are having, but how does it generally run after it is started and run/drive "normally"? Where is the injection timing set on the graph? Perhaps it's doing you a favor. I can't imagine any reason or good result from revving an almost cold started engine to high rpm, let alone approaching redline.
It is very sluggish. Occasionally when its warm it will be a little more peppy but then returns to its doggish ways. I guess the timing is the next thing I should check. And yes I completely agree revving a cold engine is a terrible thing to do. However I only did it the first time when it was hardly starting which led to it barely running then quitting after I do rev it. I guess it does sound like the timing is the culprit, perhaps it is off and the subsequent revving causes an additional advance or delay, whichever it would be which then throws it way off and is why it won't run proper until I restart.
Where should the injection timing be?
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
It is very sluggish. Occasionally when its warm it will be a little more peppy but then returns to its doggish ways. I guess the timing is the next thing I should check. And yes I completely agree revving a cold engine is a terrible thing to do. However I only did it the first time when it was hardly starting which led to it barely running then quitting after I do rev it. I guess it does sound like the timing is the culprit, perhaps it is off and the subsequent revving causes an additional advance or delay, whichever it would be which then throws it way off and is why it won't run proper until I restart.
Where should the injection timing be?
If properly set and tensioned the timing would not "move" due to revving it.
Initial static timing is set with #1 piston TDC, com locked in position and injection pump pin lock in place.
No real shortcuts allowed:
http://pics3.tdiclub.com/pdf/a4timingbelt.pdf
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Do you have VCDS?
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Without VCDS you end up spending a lot of money.

285 km is nothing. I'm running two cars with over 210k miles and they're fine: one, the wife's, is VERY healthy. My car has 170k miles (not much less than yours) and it's almost like brand new.

If you keep viewing your car as old and decrepit you'll end up treating it like it is (when it's really not). Don't blame your ignorance on dealing with the car (working on these w/o VCDS is more than ignorant) as being the car's fault, that it's ready for the scrap heap.
 

KyleMillione

Veteran Member
Joined
Jan 27, 2017
Location
Yaphank, New York
TDI
02 Jetta, 03 Jetta
I do not, I'm thinking of buying it but there's a lot of problems building up on this car and I've already spent a lot so I'm trying to see what's worth it first. I like the car but... its up to 285,000km now
These cars are not old at that mileage, they essentially last till the body/harness rots away or you choose to stop fixing them. I know people with 3-400 k MILES on these cars and they run fine. If you can do your own work they’re relatively inexpensive to repair and reliable.
 
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