VEMS'ed 200 with problems

[loxxrider]

**see bottom of page 2**

Hey, I'm not exactly sure where to start, but my car has been having issues since mid-December, so I'm finally taking the initiative to post here about it myself. Here is the wiki page for my car so you can see the history. http://www.vems.hu/wiki/index.php?page=MembersPage%2FKevinBlack%2FAudi

Basically it has had a big "hesitation" problem since day one. I will post logs to expand on this, but basically the car will buck hard at any given RPM and this corresponds to a "Mark Reset" in the logs. Every other aspect of the way the car runs is perfect. When it doesn't have the bucking problem, it runs just fine...the problem is, the bucking will happen sooner or later. If I try to get into boost, it generally happens as soon as the car sees some real load. Tonight when I was testing out the new ECU, it didn't do it when I was getting into boost though. Its really very random. It was doing it a lot at lower RPM's with not much load.

The guys at VEMS sent out a second ECU which I referred to above to see if that was the problem. Apparently its not. The ECU is connected such that everything goes through the stock wiring harness. The only things not connected through that are the coils (5 ind. coils from 034) and the wideband.

Here is a link to the latest log...

You should be able to access this. If not, just let me know. http://cid-0faf7a105daa4e3e.skydrive.live.com/browse.aspx/Public


by the way, the car runs great on the stock ECU and distributor ignition.

**edit** I would like to run the car in dist. mode also to see if that rules it out. Let me know what you all think.

[gunni]

I can´t seem to use the file you uploaded.

[Sambas]

Looks like it looses the sync. Your secondary_trigger value looks weird, usually in audi setup it's 19 (25 desimal)

[loxxrider]

I can´t seem to use the file you uploaded.

I can change the file to any type you need...let me know what format you'd like it in.

Looks like it looses the sync. Your secondary_trigger value looks weird, usually in audi setup it's 19 (25 desimal)

Ok, what should be changed in this case? I am very new to this, so please excuse my ignorance...

[loxxrider]

Just wanted to add...the screen on Megatune goes crazy whenever my computer is hooked up to it. It kinda flashes and the values all go to their default for a second...I assume that is related to the current problem?

**EDIT** now that I've searched a little, I have come to the possible conclusion that I need to type in 25 in the top box of the secondary trigger settings...is this correct? Right now, it has 65 which is 41 in hexidecimal which shows in my config dump. If someone can verify that this is correct, I would appreciate it very much.

[lugnuts]

I'm optimistic this will fix the problem. I am worried about the stability of the tuning software though.

I'm looking at the "Marcell3Bstockinjector" base config I have - and the sec trigger was correct.

At some point, the sec trig was changed to "67" in decimal which disabled it.
How this happened I have no idea.
From there, on the car the secondary trigger was changed to "Enabled" which allowed it to run.
The problem is, the "Type"and "Use" setting are/were incorrect.

I missed this and it is my fault. But my questions is -
How did it get changed in the first place? I am positive I didn't just go in and change two settings for no reason. Is it a megatune thing?

Also, it's disappointing that it was missed in the config on the Wiki page until just now. It has been up there for about 2 months.

"Thank you" Sambas for your help.

Kevin

 

[lugnuts]

Small update, the car still has the problem, even with the new Cam Sync settings.

I'll describe the problem(s), I think there is 2 different issues.

1) The car drives ok at low load and up to 3500 ish RPM.
If you give it more load, even at lower RPM, the engine starts breaking up/hesitating.

I'm waiting on new datalogs and a config dump. The Oct-20 VEMSTune is not giving him a config dump so I recommended he try the Sept-08 version that i use.
 
2) There is a communitaction problem. Every few seconds or more - the "Resets" counter goes up and up, you can watch it count up, the gauges in MT flutter. You can see the light on the USB-Serial adapter go from flashing to not flashing when the errors happen.

I had him completely disconnect the USB adapter from the ECU, to see if it was causing the driveability problem, no, the car did not get better.

I don't have a lot of experience with USB adapters, so I need help here.
All I know is this ecu worked on my bench (just power and gnd) and my computer (serial)
I'm waiting on Chris to try a different laptop and adapter.

Any advice or experiences with the USB adapters is greatly appreciated.

Kevin

[loxxrider]

OK the new config dump is now at this link. I have not been able to test the other laptop/usp adapter because my roommate is out for the day, but we will make logs as soon as possible.

http://cid-0faf7a105daa4e3e.skydrive.live.com/browse.aspx/Public?uc=1

We will also try the car in distributor mode as soon as possible (probably tomorrow) to rule out the coils as a problem.

[loxxrider]

We switched computers and usb adapters, and the ecu reset is gone. That doesn't solve the issue though. It is still getting misfires every few seconds.

I will have a log up shortly.

[loxxrider]

newest datalog

it is titled datalog2009.....

http://cid-0faf7a105daa4e3e.skydrive.live.com/browse.aspx/Public?uc=1

by the way, from what I can see the pulsewidth and duty cycle both go down to zero every time this happens. You can even see where the car was under a little bit of load, and when it happened, it shook the car so hard, that my foot hit the throttle a little more. It happens at 285.5 seconds and TP goes from about 23% to 31% haha. Spark just sits there though like normal.

[lugnuts]

Yes, there are several obvious fuel cuts, I cannot tell why. The overrun fuel cut is set at 18 kpa and working correctly. the overboost fuel cut is set to 226 kpa and was never hit.

Also, ther damn air temp sensor is still not right. Whats the deal with these Audis? The patch file is the correct PTC file recommended by the Webshop.

Chris, we are lean at ~2000 rpm from 40-70 kpa. I'll tweak and everything else this tonight and send it to you.

[loxxrider]

Yeah I noticed the air temp BS. I was assuming that we are using a file that doesn't have that fix in it or something?

I also did notice that it was lean too. That I would assume would be because the O2 isn't calibrated on this ECU yet.

[rob@vems.co.uk]

You wont be able to calibrate the sensor properly if its been used in the exhaust now.
As this isn't about hardware repairs, I'm moving this to another section.

[lugnuts]

Can anyone think of a reason for the fuel pulsewidth dropping down to zero?

We are not anywhere near the overrun kpa, and I disable the rpm values (set to 9900) because I had a problem with that setting on firmware 1.0.73.

[rob@vems.co.uk]

Have you datalogged the events?