alh limp mode after n18 delete

[n0.j0y]

i’ve recently simplified my vacuum lines and deleted the egr, egr sensor, n18 solenoid and routed everything according to the diagrams i was showed.
when i got everything done my boost gauge read 15psi and was holding as soon as i hoped on the highway and put load on the car it went into limp mode it would cut boost and would only build 2-3psi, i can shut off the carb turn it back on and it would temporarily fix it but eventually go right back, i’m assuming i have to get my car tuned, but i was wondering if any of you guys had a temporary solution other than putting all the old stuff back on, or could i fix it by clearing codes or is there a way i could change codes on vcds???.

 

[P2B]

The car is going into limp mode because there is a discrepancy between requested and actual boost pressure. The ECU will have set a code for overboost or underboost.

The issue is probably with the boost control system given it started after you messed with it. VCDS can test the boost control system for you.

 

[n0.j0y]

I understand that, i wanna know how i can tell the ecu not to go into limp mode or what i can do to trip it into thinking it’s ok.

also before the turbo would purge and do the iconic shwhoo owl noise but since i simplified it doesn’t purge or have any noise other than the normal turbo whistle, is there any correlation to me simplifying the vacuum lines?.

 

[P2B]

I understand that, i wanna know how i can tell the ecu not to go into limp mode or what i can do to trip it into thinking it’s ok.

When the ECU can't control the turbo, it puts the car into limp mode to protect the turbo. You cannot tell it to ignore the problem.

also before the turbo would purge and do the iconic shwhoo owl noise but since i simplified it doesn’t purge or have any noise other than the normal turbo whistle, is there any correlation to me simplifying the vacuum lines?.

Almost certainly. Simplifying the vacuum lines should not have affected turbo control. Something went wrong with the simplification.

 

[n0.j0y]

thank you, so im understanding it was something i did wrong, would it be possible to show you a picture and mayb you or someone else could help me pin point my error?

 

[P2B]

Vacuum lines should look like this

 

[n0.j0y]

me n my father removed the check valve to inspect it and it had a small amount of oil in it, so i took it for a quick spin to find out tht was my issue either the valve was dirty or i had it backwards anyways it spiked at 20psi but ended up going down to 15psi max.
…..i had it backwards.

my questions are if my check valve is dirty will it limit the psi? also what does it do im guessing it doesn’t let excess vacuum go back into the vacuum pump? will it be fine without it for now? and or will it hurt my engine/turbo. (or loose performance)
one last question i read somewhere tht stock turbos go up to 18psi, and mine struggles to go past 15 after it spiked to 20psi im wondering why’s tht?.

again thank you for all the help.

 

[burpod]

you can delete the checkvalve

What did you do to your MKIV today?

Found the source of the clunk coming from the back of the Golf: Anyway, old muffler removed thanks to a Sawzall and Dremel with cutting wheel. New muffler ordered.

forums.tdiclub.com

 

[P2B]

one last question i read somewhere tht stock turbos go up to 18psi, and mine struggles to go past 15 after it spiked to 20psi im wondering why’s tht?.

Yes, stock turbo can handle 18psi safely but the stock tune does not call for much over 12.

 

[burpod]

1950mbar absolute is max request in normal temps. 13.8psi or so

 

[CanadianALH]

me n my father removed the check valve to inspect it and it had a small amount of oil in it, so i took it for a quick spin to find out tht was my issue either the valve was dirty or i had it backwards anyways it spiked at 20psi but ended up going down to 15psi max.
…..i had it backwards.

my questions are if my check valve is dirty will it limit the psi? also what does it do im guessing it doesn’t let excess vacuum go back into the vacuum pump? will it be fine without it for now? and or will it hurt my engine/turbo. (or loose performance)
one last question i read somewhere tht stock turbos go up to 18psi, and mine struggles to go past 15 after it spiked to 20psi im wondering why’s tht?.

again thank you for all the help.

Sticky vanes maybe. If it’s spiking like that. Take a log?