Variant TDI
Veteran Member
Ah... thanks. I'll check my IQ when I get home. I had 'raised' it previously from 3 to 5.6 to reduce smoke. I guess I'll have to adapt again to get back to where I want to be.
Well after setting mine back to the "modified" mode and running two full tanks of fuel, I'm right back to my normal 47 MPG average. With the EGR set at Stock values, I was getting 41 MPG over several tanks. To note, my area has also been out of the "Winter" blend of fuel for months also.JettaJoy said:Yep, same as pfiermka. All stock. I even checked the EGR after I changed it back to make sure it was seating correctly.
Will see if I get back where I was and report.
Very well put. When I put mine back to stock I noticed more power but as for mpg I stayed the same.jollyGreenGiant said:The root issue this thread is talking about is not whether EGR is actually being applied physically but whether the adaptation value for the EGR channel has been modified off of 32768 in an effort to reduce the EGR flow. When this is done, it modifies other maps accordingly and reduced output and efficiency are noted. I hope this clarifies the issue.
Exactly. If the EGR is physically blocked and the MAF signal is modified, either via a diode drop, MAF-twist or some other means, there should be a gain in fuel mileage with no driveability issues. Or at least no mileage penalty without the intake plugging.jollyGreenGiant said:The root issue this thread is talking about is not whether EGR is actually being applied physically but whether the adaptation value for the EGR channel has been modified off of 32768 in an effort to reduce the EGR flow. When this is done, it modifies other maps accordingly and reduced output and efficiency are noted. I hope this clarifies the issue.
I could be wrong, but it appears that reduced EGR adaptation must be followed with advanced timing adaptation to offset the retard of combustion. I've played a bit, but still learning, so i turned it back to stock calibrations.jollyGreenGiant said:VAG-COM adaptation for EGR plays with things like IQ and timing along with EGR, I never had any luck with reduced EGR adaptation, it effected too many other things for my liking and I too received a 3-4 mpg drop in mileage with it adapted on it's lowest setting along with a similar drop in torque. There's better ways to handle the EGR than through the adaptation method on the rotary pump TDI's IMO.
The real question is, does raising the EGR adaptation to the highest value ( max EGR ), increase IQ and timing parameters and thus fuel economy? A scientific analysis on default and max settings with a couple tanks of carefully logged consumption along with some full load logs of 004,003,011 with default and max values may shed some light on the subject. Any volunteers?honda_vtec2 said:I could be wrong, but it appears that reduced EGR adaptation must be followed with advanced timing adaptation to offset the retard of combustion. I've played a bit, but still learning, so i turned it back to stock calibrations.
When i first got this TDI, EGR hose was detached from the valve. Mileage was around 900km per tank. So i plugged it back in and mileage went up a slight bit, to around 950km per tank with the same non-vented fueling /driving conditions. This was measured briefly with 17' low profile wheels.
I'd volunteer, but the weather up here is fluctuating a lot to get good results. If this thread is still going come spring. I'm in. The last time i played with the EGR settings on the car. It didn't drive as nice, so i went back to stock. I took a small drive around the block and didn't even get to the point of starting logging. I'm not sure if this is due to an intake build up of soot. Last time i measured about 1-2mm or oily stuff around the EGR valve.jollyGreenGiant said:The real question is, does raising the EGR adaptation to the highest value ( max EGR ), increase IQ and timing parameters and thus fuel economy? A scientific analysis on default and max settings with a couple tanks of carefully logged consumption along with some full load logs of 004,003,011 with default and max values may shed some light on the subject. Any volunteers?
This time of the year is bad to be doing this kind of thing also, the weather at least in my neck of the woods is too variable.
You should have about 28 in/hg at the vacuum supply to the EGR solenoid and depending on the solenoid's duty cycle you will have a percentage of that reaching the EGR, 50% duty cycle would be about 14 in/hg and so on.viersam@gmail.com said:does anyone know what the vacuum should be on the EGR? suction wise?