Excessive white smoke

[Cook561]

I have my 2003 Jetta ALH with 347,000km, I have an excessive amount of white smoke on startup and strong unburnt fuel smell, smoke out my driveway kinda white smoke.

On start up the rpm’s will dance a bit then settle down. Car runs fine and everything when driving but still unburnt fuel smell, and still some smoke not as bad as startup tho.

From what I can tell the guy I bought the car from didn’t do much maintenance on the car. Just ordered new injectors for it, thinking an injector might be dumping fuel or leaking . Any other suggestions that it could be besides injectors ? Should also add the car is deleted.

 

[fatmobile]

Air in the fuel will cause white smoke.

 

[Vince Waldon]

Retarded timing is another common cause of unburnt fuel aka white smoke, as is low compression on one or my cylinders.

 

[oilhammer]

Yep, lots of things to check. Some start up smoke, especially when very cold, is normal (it is even mentioned in the manual). But it shouldn't be excessive.

You could have pump problems, injector problems, engine problems, fuel prime problems, sensor problems, etc. I would verify there are no DTCs stored, verify the timing is correct, and verify all the temp sensor values into the ECU are correct.

Next I'd try some fuel system cleaner or even a purge to see if anything improves. Go after the low hanging fruit first.

 

[burpod]

blindly ordering new injectors isn't really a good approach. like oilhammer suggested.. do that stuff. it's likely a simple problem. pretty rare to get a streaming injector that "dumps/leaks fuel", if they were doing that (streaming or horrible spray pattern) you'd most likely have lot more smoke all the time. you can check injector balance in vcds for a sanity check. some basic vcds logs would be the place to start and good chance with minimal effort and zero $$ you could diagnose the likely problem within an hour. an 011-001 log would be good. check sensor temps when car is at ambient, block 007 key on/car off, sanity check barometric/MAP block 010 key on/ car off. if it's deleted and has a tune, that could complicate things. if egr is deleted, its most definitely not optimal without changes to the tune especially in cold weather

 

[CanadianALH]

I might also suggest looking at the pressure relief valve in the IP.

 

[JETaah]

Cold or hot starts...or both? Glow plugs working? How long does it take to start the engine? Maybe crappy glow plugs or corroded harness connections...good enough to satisfy the ECU requirements for resistance but not good enough to heat? What brand are they?