VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum banner
Cancel

made my first test with VCDS !!! comments...

2909 Views 11 Replies 5 Participants Last post by  patallen, 
P
so yes i just bought a full VCDS ! i am very happy.

I made a first log test, car was idling and i bliped the throtle 3 times...i am a bit worried, the actual MAF doesnt realy change...bad maf ??
i will perform a road test soon.

Attachments

See less See more
Reply
Save
Like
1 - 12 of 12 Posts
V
It's at idle and I see MAP which is manifold pressure (boost) , not MAF which is the air sensor. You won't see much boost building unless the engine is under load.
Reply
Save
Like
P
thanks, i slowly start to learn on this.

yes it was at idle and there isnt much boost...

I will do the proper test soon, ie, maf test in 4th/5th and boost test at speed.
Reply
Save
Like
Keithuk
patallen said:
so yes i just bought a full VCDS ! i am very happy.
Click to expand...
So you would be happy if we had a VCDS section on here then?

Please put your comments in http://www.myturbodiesel.com/forum/f10/vcds-vag-com-section-here-3918/#post19663 ;)
Reply
Save
Like
P
Keithuk said:
So you would be happy if we had a VCDS section on here then?

Please put your comments in http://www.myturbodiesel.com/forum/f10/vcds-vag-com-section-here-3918/#post19663 ;)
Click to expand...
i didnt knew there was a dedicated section for vcds, cool to know, thanks!!
Reply
Save
Like
chittychittybangbang
There isn't but if enough people ask I will add one.
Reply
Save
Like
P
chittychittybangbang said:
There isn't but if enough people ask I will add one.
Click to expand...
well, as long as it gets a real purpose, i mean, that it wont get filled up with non vcds related posts, i would say go ahead !!
Reply
Save
Like
P
2
Guys, i dont want to be a bother, but i would like your comments. I made a proper test run for both the map and the maf.

Maf seems ok, but the map test suggest that the turbo response is quite slow.

That turbo has been taken apart recently because the vnt mechanism was seized. I had to weld material on the lever, the one that gets worn all the time. It moves freely without any hicups now.
I had to mess up the adjustement of the rod. So, i am wondering if working out the rod lenght affect the boost response...

Also, i made the timing check, and for some reason the temperature never get hot enough, even after a 5 minute highway run...altough the needle in the car is dead on 90...what sensor is in fault ? otherwise the timing is in the upper range on the graph.
fwiw, i am in Quebec and it is below freezing point, i dont know if this affect the temperature reading or not...

any comments would be apreciated !!

Attachments

See less See more
Reply
Save
Like
chittychittybangbang
Check the coolant temp sensor - it's on the driver's side head on a coolant flange. It will make the car's computer think it's not warmed up.

Yes, the rod length affects boost response completely. It should be checked with a vacuum gauge for when it moves.

Your MAF values look fine. The MAP also looks acceptable but it could be improved. Minor deviation is fine because if you quickly step on the accelerator pedal you get a minor delay in boost response while it builds up. Check the VNT actuator position.
Reply
Save
Like
P
chittychittybangbang said:
Check the coolant temp sensor - it's on the driver's side head on a coolant flange. It will make the car's computer think it's not warmed up.

Yes, the rod length affects boost response completely. It should be checked with a vacuum gauge for when it moves.

Your MAF values look fine. The MAP also looks acceptable but it could be improved. Minor deviation is fine because if you quickly step on the accelerator pedal you get a minor delay in boost response while it builds up. Check the VNT actuator position.
Click to expand...
thanks for the suggestions. I am suspecting a leak somewhere...the temperature sensor potentialy in fault is the one right under the vacuum pump right ?

i guess there is a mode in the VCDS to check it...

As a general rule of thumb, if there is ever one for that, if i shorten the rod lenght (very litle, i know !!) it should make the boost occurs faster isnt it ?
it is probably 2-3mm longer than it was before after i messed it all up when i "rebuilded" the turbo.

fwiw, that engine had the t-belt broke, so valves, lifters and all the crap around had to be replaced.
Got the parts and VCDS from Brian at roseland technical services, very nice guy to say the least.

thanks !!
Reply
Save
Like
G
Adjusting the rod works to the point where it doesn't and makes things worse. Get a hand held vacuum pump and test it yourself to the specs. They're really cheap and worth the investment.
Reply
Save
Like
P
grizzly said:
Adjusting the rod works to the point where it doesn't and makes things worse. Get a hand held vacuum pump and test it yourself to the specs. They're really cheap and worth the investment.
Click to expand...
i understand there is limit to respect with this adjustment, i am not expecting magic there, but was wondernig if someone had experience with such low ramp boost and by shortening a litle bit the rod, assuming it is on the "long" side of the adjustment.

thanks.
Reply
Save
Like
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum
A forum community dedicated to Audi, Volkswagen, Porsche, and all turbo diesel owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, TDI, maintenance, and more!
Full Forum Listing
Explore Our Forums
VW Mk4 Jetta, Golf, New Beetle, Passat TDI forum Mk5 VW Jetta, Sportwagen, and Audi A3 TDI forum New TDI forum member introductions VW Mk6 Golf, Jetta, Beetle, Sportwagen TDI forum General Diesel Discussion
Top