blue smoke on start, rough idle, low power

mssanger

Member
Joined
Nov 11, 2008
Location
Ann Arbor
TDI
mk2
Ok I searched and didn't come across anything fitting profoundly so here goes...

I bought a tdi, tranny, ecu, and harness from a 97 passat 140k. I put it into a mk2 gas Jetta, running the gas tank and gas pumps. I have driven it for about two months on and off and I become fed up with its condition.

The car starts initially pretty rough. It gives a large puff of blueish smoke and idles rough, shaking the entire car. If I let it sit for a min and give it some pedal, it doesn't really want to rev, but it will if I give it more and more pedal until it revs up, kicking on the alternator with another cloud of blue smoke. I can drive down the road and see blue smoke still coming out behind me (considerably less than at startup) for the first 5 or 8 mins as I accelerate. The smoke seems to dissapear when its warmed up completely, but the car in general lacks power. If I appraoch a hill on the expressway, I accelerate to gain momentum to move up it, otherwise the car gradually slows below the speed limit. If I keep the engine above idle, it is fairly smooth, although could be better. When entering the idle mode though, the car drops into this terrible shaking idle. What could it be? I know the N75 is bad, so I bypassed it and installed a boost guage to monitor it. The boost seems right and stays under 10 psi. It feels like misfiring or out of time.

I completely cleaned the intake manifold.
Cleaned the intake runners on the head.
Dissasembled and cleaned turbo. Looked to be in good shape.
Sealed up any boost leaks.
Cleaned the MAF.
Fixed the glow plug circuit. All working with indicating light.
Sealed any vacuum leaks.


Basically it has to be fuel right? Are the gas pumps to much for it? Is the injection pump failing?

Sorry for all of the words.
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Got vag-com?

Invaluable tool for troubleshooting VW/Audi cars.

Critical tool when you need to check injection timing.

Basically, the blue/gray smoke on cold start is unburnt diesel. It sounds like your timing needs to be advanced. Advancing the timing should also give a little more power.

Tony
 

validius

Lacking in ZDDP
Joined
Oct 9, 2006
Location
Grand Rapids, Michigan
TDI
1997 GTI TDI
You live in the same area as me, I PMed you with contact info!

I have Vag-Com and a compression tester!

mssanger said:
Ok I searched and didn't come across anything fitting profoundly so here goes...

I bought a tdi, tranny, ecu, and harness from a 97 passat 140k. I put it into a mk2 gas Jetta, running the gas tank and gas pumps. I have driven it for about two months on and off and I become fed up with its condition.

The car starts initially pretty rough. It gives a large puff of blueish smoke and idles rough, shaking the entire car. If I let it sit for a min and give it some pedal, it doesn't really want to rev, but it will if I give it more and more pedal until it revs up, kicking on the alternator with another cloud of blue smoke. I can drive down the road and see blue smoke still coming out behind me (considerably less than at startup) for the first 5 or 8 mins as I accelerate. The smoke seems to dissapear when its warmed up completely, but the car in general lacks power. If I appraoch a hill on the expressway, I accelerate to gain momentum to move up it, otherwise the car gradually slows below the speed limit. If I keep the engine above idle, it is fairly smooth, although could be better. When entering the idle mode though, the car drops into this terrible shaking idle. What could it be? I know the N75 is bad, so I bypassed it and installed a boost guage to monitor it. The boost seems right and stays under 10 psi. It feels like misfiring or out of time.

I completely cleaned the intake manifold.
Cleaned the intake runners on the head.
Dissasembled and cleaned turbo. Looked to be in good shape.
Sealed up any boost leaks.
Cleaned the MAF.
Fixed the glow plug circuit. All working with indicating light.
Sealed any vacuum leaks.


Basically it has to be fuel right? Are the gas pumps to much for it? Is the injection pump failing?

Sorry for all of the words.
 

validius

Lacking in ZDDP
Joined
Oct 9, 2006
Location
Grand Rapids, Michigan
TDI
1997 GTI TDI
TonyJetta said:
Got vag-com?

Invaluable tool for troubleshooting VW/Audi cars.

Critical tool when you need to check injection timing.

Basically, the blue/gray smoke on cold start is unburnt diesel. It sounds like your timing needs to be advanced. Advancing the timing should also give a little more power.

Tony
If he is running gasser fuel pump he has WAY to much pressure. Im guessing the IP might not be able to control delivery like it should!
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
I hadn't considered that!

Oh, well...engine transplants!

Tony
 
Top