Would this work?
- Thread starter GPM2010
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That depends. A scan tool can only tell you what the car knows. So the question is, does the car itself know what's wrong?
How long does the stumble last after a cold-start?
-Uwe-
How long does the stumble last after a cold-start?
-Uwe-
OK. Here we go from the beginning. Bought this car in 2007. It was in an accident and bondo'd together in front. Car came from Texas originally, then crashed/re-bondo'd and auctioned off to Wisconsin. From there went to fly-by-night dealer in Joliet, Illinois where I found it.
Air bag light was still on. Bought it then for 17.5k which was a steal for being 2 years old and 48k miles. My theory is: Someone did a cheap chip tune to ECM, wound it out and into a tree. I'm getting 8 second 0-60mph runs when stock says 10.2 seconds. Go figure.
Cold starts where always stumbly. Took to auto rebuilder and had them break down and rebuild proper. Two weeks after, the trans went out. Rebuilt that. Replaced many sensors, glow plugs, temp sensors, thermostat, safety belts, all the usual maintenance. Still running funny on cold acceleration. Took out EGR and cleaned, no difference. Took out intake manifold and found 1/8" soot throughout inside, YUCK ! Cleaned in hot solvent tank, then replaced, and stopped that issue with cold acceleration.
Took to dealer complaining about this, they found nothing. Of course it won't act up for them. Nothing wrong they said.
Have tried Diesel Purge and ran/started perfect while on this stuff. I believe it had Cetane in it which later on helps cold starts in winter due to more volatile and combustable. Didn't use it above 50 degrees. Later went back to usual crappy starts under 40 degrees. Sometimes when hot, sitting in parking lot for 1/2 hour, go to start and get rough stumble then smoothes out start. Runs perfect throughout the range.
This last winter was the roughest it's ever seen and was almost unstartable some days. It's the fuel with 11% bio in it, I'm sure. Most diesel didn't run or start in negative degree days.
Replaced the glow plugs a few times. The voltage is at 7v which I believe is normal until the coil light goes out, which goes to 3-4v.
Lately I bought the Diesel Power DIGI tuner chip to try and has 16 settings of performance: 1-F. Came on factory setting of 9 which adds roughly 20-25 hp. Still started with stumble, yet could feel the difference in response. Only it looped a bit when gentle acceleration applied. Tuned it to "A" and that's when the dash said, "Engine Workshop" on every start". Ran fine, just annoying messages. After 5-6 starts like this, threw a P0200 code. Injector circuit open or voltage (expecting low), depending on which scanner I used. Checked Fuel injection harnesses and put tiny amount of dielectric grease on leads. No difference. Spoke to seasoned TDI mechanic and said ECM may be corroded or faulty and/or bad ground from battery. Checked the battery ground and wire brushed it off and applied kopr cote connection paste for better continuity. No difference there. That's pretty much where I stand. Any ideas from this ??
Will this software help diagnose or track down the issues u think ?
Air bag light was still on. Bought it then for 17.5k which was a steal for being 2 years old and 48k miles. My theory is: Someone did a cheap chip tune to ECM, wound it out and into a tree. I'm getting 8 second 0-60mph runs when stock says 10.2 seconds. Go figure.
Cold starts where always stumbly. Took to auto rebuilder and had them break down and rebuild proper. Two weeks after, the trans went out. Rebuilt that. Replaced many sensors, glow plugs, temp sensors, thermostat, safety belts, all the usual maintenance. Still running funny on cold acceleration. Took out EGR and cleaned, no difference. Took out intake manifold and found 1/8" soot throughout inside, YUCK ! Cleaned in hot solvent tank, then replaced, and stopped that issue with cold acceleration.
Took to dealer complaining about this, they found nothing. Of course it won't act up for them. Nothing wrong they said.
Have tried Diesel Purge and ran/started perfect while on this stuff. I believe it had Cetane in it which later on helps cold starts in winter due to more volatile and combustable. Didn't use it above 50 degrees. Later went back to usual crappy starts under 40 degrees. Sometimes when hot, sitting in parking lot for 1/2 hour, go to start and get rough stumble then smoothes out start. Runs perfect throughout the range.
This last winter was the roughest it's ever seen and was almost unstartable some days. It's the fuel with 11% bio in it, I'm sure. Most diesel didn't run or start in negative degree days.
Replaced the glow plugs a few times. The voltage is at 7v which I believe is normal until the coil light goes out, which goes to 3-4v.
Lately I bought the Diesel Power DIGI tuner chip to try and has 16 settings of performance: 1-F. Came on factory setting of 9 which adds roughly 20-25 hp. Still started with stumble, yet could feel the difference in response. Only it looped a bit when gentle acceleration applied. Tuned it to "A" and that's when the dash said, "Engine Workshop" on every start". Ran fine, just annoying messages. After 5-6 starts like this, threw a P0200 code. Injector circuit open or voltage (expecting low), depending on which scanner I used. Checked Fuel injection harnesses and put tiny amount of dielectric grease on leads. No difference. Spoke to seasoned TDI mechanic and said ECM may be corroded or faulty and/or bad ground from battery. Checked the battery ground and wire brushed it off and applied kopr cote connection paste for better continuity. No difference there. That's pretty much where I stand. Any ideas from this ??
Will this software help diagnose or track down the issues u think ?
Hard to say. We certainly can't guarantee that it will; the problem may be due to something the car itself is not capable of detecting, in which case no scan tool will be of help. What are you using for a scanner now?
-Uwe-
Actron scanner, all purpose & also have a VAG Specific scanner. Both throw different codes usually about the same issue.
When the MAF sensor is disconnected, it runs awful. So I know that's good. The only thing left besides replacing the injectors is the ECM. Wonder if it could have gotten damaged in accident.
When the MAF sensor is disconnected, it runs awful. So I know that's good. The only thing left besides replacing the injectors is the ECM. Wonder if it could have gotten damaged in accident.
Software doesn't diagnose anything. In some cases (fault codes) the car does "Self-diagnostics" and software tells you what the car knows. In other cases the software can be used to look at certain values in real-time and the user diagnoses issues based on those values.
-Uwe-
-Uwe-
Well, a cheap Chinese KKL cable and the (free) shareware version of VCDS-Lite is probably less of a waste than a new ECM, particularly if the ECM doesn't turn out to be the source of the problem. 
-Uwe-
-Uwe-
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