EGR TDI 1.9 90hp AGR - Air Mass Actual higher than Specified at IDLE

IbizaUser

Member
Joined
Sep 21, 2020
Location
Ibiza
TDI
90CV AGR
Hi, i have this photo of my car



So at idle my car sonds "bad" and testing it with vagcom i find this (car is a seat ibiza 6k2 from 1999) with the hood open, if I operate the black mushroom on the side of the EGR a bit, the number in Mass Air Actual goes down and i can get it to 265-285.. with the surprise that the vibration and sound of the engine improves much better

maf sensor defective? N18? or maybe a leak?

Thank you from IBiza, spain
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2007 Seat Alhambra 2L tdi
That sounds like the anti shudder valve you're messing with, the egr actuator is the big shiny one on top.

If you think the egr is bad at all just pull the vacuum pipe off it and stick a little bolt in the end of the pipe to block it then see how the car is. It's the thicker vacuum pipe going to the shiny disc on the top.

Also look up other tests with vagcom/vcds, check the injection timing and the injection quantity, if the IQ is wrong it can cause a rough idle.
 

IbizaUser

Member
Joined
Sep 21, 2020
Location
Ibiza
TDI
90CV AGR
That sounds like the anti shudder valve you're messing with, the egr actuator is the big shiny one on top.

If you think the egr is bad at all just pull the vacuum pipe off it and stick a little bolt in the end of the pipe to block it then see how the car is. It's the thicker vacuum pipe going to the shiny disc on the top.

Also look up other tests with vagcom/vcds, check the injection timing and the injection quantity, if the IQ is wrong it can cause a rough idle.
thanks, gonna try "struggling" the vacuum pipe and look at the sound
timing is 89-90, i know that is not the correct value but previously it was 25.. i have to take it to 45-50 i think

ok, gonna check that too.. 3 days ago i changed the 3 motor mount and the engine is less noisy in the passenger compartment/cabin, but with more vibrations the first day, maybe with the use the mounts "accommodates"

thanks!
 

IbizaUser

Member
Joined
Sep 21, 2020
Location
Ibiza
TDI
90CV AGR
That sounds like the anti shudder valve you're messing with, the egr actuator is the big shiny one on top.

If you think the egr is bad at all just pull the vacuum pipe off it and stick a little bolt in the end of the pipe to block it then see how the car is. It's the thicker vacuum pipe going to the shiny disc on the top.

Also look up other tests with vagcom/vcds, check the injection timing and the injection quantity, if the IQ is wrong it can cause a rough idle.
hi,i try all that and nothing changes..


Blocking the vacuum pipe,nothing
blowing down the tube to see if the EGR leaks air, i cant, looks like its fine

the air mass actual its 445 and number never goes down, its like te egr never opens

try to disconnect MAF and number goes up to 550

and IQ is like 3.6 on idle, maybe sometimes go up to 3.8 and comes back to 3.6
 
Last edited:

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2007 Seat Alhambra 2L tdi
Try bumping the IQ up a touch, the lower the number the more fuel and it can cause a rougher idle, look up the hammer mod.
 

IbizaUser

Member
Joined
Sep 21, 2020
Location
Ibiza
TDI
90CV AGR
Try bumping the IQ up a touch, the lower the number the more fuel and it can cause a rougher idle, look up the hammer mod.
But i read that 3.6 IQ is like stock no?

I think the cause of rough idle is cause my EGR doesnt open and car thinks the EGR is working (like its blocked accidentally maybe dirty or N18 not working) and thats why MAF actual reading everytime 445 and ECU wants 265, if i move the anti shudder valve and "cut" some air , the Maf Actual gets down to 265-300 depending on the applied force in the anti shudder valve and the engine sounds much better, like a kitten.. so car's taking "too much air"

Maybe thats right? Thanks!!
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2007 Seat Alhambra 2L tdi
Pop on a blanking plate for the egr and see how it goes, if that works then you'll know it is the egr

regarding IQ 3.6 is ok but every engine is different, mine ran best a bit over 4.
 

IbizaUser

Member
Joined
Sep 21, 2020
Location
Ibiza
TDI
90CV AGR
Pop on a blanking plate for the egr and see how it goes, if that works then you'll know it is the egr

regarding IQ 3.6 is ok but every engine is different, mine ran best a bit over 4.
it was the N18, ill change it for 10€ and now works perfectly, maf actual and maf specified now at 265 the 2! Thanks!
 
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