Car doesn't pull, logs posted, advice needed ? ? ?

[GeorgeTDI]

I have a 1.8 TSI manual hatchback pre-facelift. After driving it for a month or so, there are clear issues with the engine. Most of the time the car doesn't pull like it should. I have driven other cars with the same 1.8 engine and they have an even strong pull through the rev range, from 2500 to 6000 rpm. Mine generally is weaker than that and is very inconsistent. Sometimes it pulls really hard, but that's rare and usually only in 3rd or 4th. Most of the time it pulls weaker than an 1.4, I have not been able to get to 100kph faster than 8.3 s, usually around 9 s or more. Some other times it starts weak and gets stronger after 3500 rpm, that's also rare. The only engine related error is the one here. Another issue I have is terrible fuel economy, around 15-16 L / 100 km in the city without flooring it. When cruising in second around 2200 rpm I see a steady 11-12 L/100.

I have made some logs with VAG-COM today and will do some more tommorrow. In the logs the pedal is down to the floor starting around 2200-2500 rpm. They are made in 3rd gear. Note that logs 05 and 06 have 2 different parameters from the first four, which I thought were also important. I would appreciate any opinions about these logs.

Regarding the logs, the guy with the vag-com said the sample rate is about 1/second, apparently that could be a lot better. He also said he can only record 12 parameters at a time, which seems to be a vag-com limitation. The parameters logged so far are in post #7 below. If you can recommend any changes for tommorrow when I make fresh logs, different parameters or anything else regarding procedure, I would appreciate that too.

 

[golfdave]

For starters those logs show he is using VCDS 18.9...& not 19.6...

I'm not an expert on this specific engine, but the actual Lambda logs (last column & item G831) in LOG6 it goes from around the 0.9 to 1.1 mark to 6.6. & then hits 19.3 ..then goes down to 15.3 then 13.7 then hits 1.1 again.....lambda sensors on the way out???

 

[MeltedSolid]

Some of those logs seem pretty normal, but some of them do seem to have weird fluxuation, going between 7 and 10 psi of boost randomly. It's hard to say what it looks like without more data points on the log. See if you can figure out a way to get logs with a much higher polling rate, these logs seem to have 1.5s+ between each point, and most of what I'm used to has 1/10th of a second or less between points.

 

[GeorgeTDI]

Is it a limitation of vag-com to record a maximum of 12 parameters at a time ?

 

[MeltedSolid]

Probably, the JB4 can do 33 at a time. Though I think it only gets data from ~25 parameters.

 

[GeorgeTDI]

Which of the parameters in these logs are not needed ? Which additional ones would you recommend be added ?

 

[GeorgeTDI]

So far I have logged the following parameters:

IDE00021 - Engine speed
IDE00148 - Median injection timing
IDE00155 - Timing angle retardation cylinder 1
IDE00190 - Charge air pressure specified value
IDE00191 - Charge air pressure: actual value
IDE00348 - Intake air temperature
IDE00593 - Ignition timing adjustment cylinder 1
IDE04677 - O2 sensor 1 bank 1: O2 sensor actual value
IDE07574 - Long-term fuel trim bank 1 at idle
IDE00472 - Mean injection quantity
IDE01932 - High pressure pump injection volume
ENG101828 - Air mass
ENG104044 - Engine load
ENG102763 - Lambda probes actual: bank1

 

[GeorgeTDI]

Far from it The official figure is 7.6, but Car and Driver did it in about 7 seconds.

Plus like I said, I've driven other cars with the 1.8 TSI engine and they pull significantly better than mine.

 

[GeorgeTDI]

Please read what I wrote above, the car simply doesn't pull as well as it should.

Does anyone have any recommendations on what parameters to add to the log / exclude from the log tommorrow ?

 

[Navi]

A difference of 1 second can simply be from them getting a better launch than you. There’s probably nothing wrong with your car. You just need to practice your launching.

useless

 

[MeltedSolid]

I think my best theory at the moment is a faulty wastegate, but I'm not sure (maybe bad o2 sensor, it does seem maybe a bit odd that the lambda goes above 1 while pulling, but I know they try to make it close to 1). I think the parameters you have logged are probably enough, the only other one that would be useful is trims, but that's more useful for tuning for power. The most important would probably be to log at a higher polling rate so we can get a clear picture of the weird fluctuation.

 

[GeorgeTDI]

I think my best theory at the moment is a faulty wastegate, but I'm not sure (maybe bad o2 sensor, it does seem maybe a bit odd that the lambda goes above 1 while pulling, but I know they try to make it close to 1). I think the parameters you have logged are probably enough, the only other one that would be useful is trims, but that's more useful for tuning for power. The most important would probably be to log at a higher polling rate so we can get a clear picture of the weird fluctuation.

Are there any trims other than "Long-term fuel trim bank 1 at idle" ?
Also the car seems to be generating requested boost ? But maybe not as quick as needed ?
One more thing I'll try today is remove one of the mufflers, since I have 3 installed Euro-style, the middle one being out of place

 

[Navi]

That’s not very nice. C&D uses professional drivers to get the best numbers out of their test cars. I wouldn’t call the kid useless just because he can’t launch his car like them.

Don’t manipulate what I mean. I was talking about your existence and posts as being useless.

I’m thinking it could be waste gate or DV

 

[GeorgeTDI]

So I got logs. Like I got logs We used "Group UDS requests" and VAG-COM didn't record more than 8 parameters at once. So we did more runs with different sets of parameters, several runs for each from 2000 to 6000. In the logs, the pedal is down to the floor starting around 2000-2300 rpm. The only exception is Set 5 with Misfire values, where the pedal is down when the rpm climb toward 6000, but after that the log continues at lower rpm to catch more misfires. There are also 3 long logs in it (05-07) with no WOT to catch more Misfires at lower rpm. Outside air temps were about 9-10 C and elevation around 85 m. All logs were done in 3rd gear, except for Set 5 where the WOT part is in 3rd and the rest varies.

Here are the different sets of parameters logged:

Set 1
Engine speed
Median injection timing
Timing angle retardation cylinder 1
Charge air pressure specified value
Charge air pressure: actual value
Ignition timing adjustment cylinder 1
Lambda probes actual: bank1
Lambda probes specified: bank1


Set 2
Engine speed
Timing angle retardation cylinder 1
Charge air pressure: actual value
Ignition timing adjustment cylinder 1
Long-term fuel trim bank 1 at idle
Intake air temperature
Lambda probes actual: bank1
Lambda probes specified: bank1


Set 3 (mind the parameter order)
Engine speed
Timing angle retardation cylinder 1
Fuel low pressure: actual value
Fuel high pressure: actual value
High fuel pressure: specified value
Low fuel pressure: specified value
Ignition timing adjustment cylinder 1
Lambda probes actual: bank1


Set 4
Engine speed
Timing angle retardation cylinder 1
Charge air pressure specified value
Charge air pressure: actual value
Ignition timing adjustment cylinder 1
O2 sensor 1 bank 1: O2 sensor actual value
Lambda probes actual: bank1
Lambda probes specified: bank1


Set 5 - Misfires
Engine speed
Timing angle retardation cylinder 1
Charge air pressure: actual value
Ignition timing adjustment cylinder 1
Misfires per 1000 revolutions of cylinder 1
Misfires per 1000 revolutions of cylinder 2
Misfires per 1000 revolutions of cylinder 3
Misfires per 1000 revolutions of cylinder 4
(incl. Median injection timing - one log)
(incl. Lambda - one log)

 

[TwinDad]

Just throwing it out there, but have the plugs been changed? Have you checked them. Old and worn plugs will hurt performance. Also you are getting misfires. Other things will also cause the misfire code, but first place to check is plugs and coils.