Help! 17705 fault code, no boost control, and pre-detanation

[DurkWorks]

Some one please help me.
I drive a seat leon Mk1 cupra. auq engine code. Since I have owned the car I have replaced almost everything to solve this issue....... I don't really have any boost control, (when going uphill especially I can smoothly apply more and more throttle but the boost doesn't build up and the gauge stays on 0 and it's sounds like my recirculating valve opens (large hiss) then when my foot hits the floor it's suddenly kicks in and I get 30psi of boost.(I know that's high but I have mods of which the list will follow) I have pre detonation when giving her the beans, and I have the fault code 17705 (pressure difference between turbo and throttle valve) every now and again it will hit limp mode and only give about 7 maybe 8 psi boost which is sorted by a quick turn off and on with the key. I think this is due to the 17705 fault code. It also gets worse when the engine is hot. This does point me to a boost leak but none found with a smoke machine.

I have replaced the following

Ram Air box and filter
New genuine mass air flow(in 80mm housing)
Supersize intake pipe
Had a race dynamic recirc valve but fitted a good 2nd hand forge 007 with a service first
New genuine n75 valve
New k04 001 turbo
3" down pipe and decat 2.5"long life centre and rear.
Performance fuel pump
Cupra r 386cc injectors
All deletes done( sai, evap, n112 and n249 valve's, breather, and brake servo deletes.)
Silicone vac pipes and boost pipes.
I have fitted a good 2nd hand throttle body and cleaned and adapted it.
Air intake sensor good 2nd hand
Map sensor good 2nd hand
Changed literally every gasket and o ring on the hole engine.
I have had a smoke test for leaks and no leaks found.
I have had it mapped to about 260 atm but needs a new tune with the new turbo but I have tried a standard map and the car still has these faults. Just to rule out software from mapping.

I am stuck now for ideas. Any help would be appreciated. Its a long essay I know but I have tried to fit as much info as possible to help diagnose the issue.

 

[Damien Wood]

30psi is high, maybe a bad map. Actuator fault maybe?

 

[Damien Wood]

Just seen about the map. Difficult one mate, I would check the recirc and the boost control valve again.

 

[Damien Wood]

Also clean all electrical connections

 

[DurkWorks]

30psi is high, maybe a bad map. Actuator fault maybe?

I know 30 psi is a tad high but God she goes lol but it only spikes at 30 and will fade off to about 23 on red line. (if it's not pre detonating to badly lol.) I have already blown one engine up and swapped a good engine over and still have the fault so it's something on the car. Has to be lol. It has a new hybrid turbo fitted 2 weeks ago with a new actuator installed that came with the turbo. Faults still there. And I have tried a standard 180 maps and faults still occur. Thanks for the reply. I need some more ideas lol.

 

[DurkWorks]

The recirc valve came off my mates audi tt bam and it ran sweet. I have cleaned it and regreased the piston inside and made sure the seals were good. This car is where all my 2nd hand bits come from. It was written off but engine ran perfect (even after the smash haha)

 

[DurkWorks]

I will clean all my connections though, I haven't tried that. Could be something simple like that. Bad connection = false reading lol

 

[Damien Wood]

You running a hybrid on a stage1 map? I think you need a proper map for all your hardware

 

[DurkWorks]

I hope the boost control valve is OK. I only bought it last week from the stealer ship 75 pounds. I thought best to go with standard and genuine for parts like this.

 

[Damien Wood]

S

I hope the boost control valve is OK. I only bought it last week from the stealer ship 75 pounds. I thought best to go with standard and genuine for parts like this.

its the most obvious thing to go to tbh, it’s confusing this one. Hopefully someone else has an idea for you pal. Sounds electrical to me, even a dodgy Ecu. It’s all guessing though bro

 

[DurkWorks]

You running a hybrid on a stage1 map? I think you need a proper map for all your hardware

No it's a stage 2 map but I now have a hybrid so should push more than 260 out when mapped in again. A stage 1 no mods is around 215 from 180. A stage 2 with K03s and other mods 260ish.a stage 2plus or 3 is with a hybrid turbo aswell. So should be about 300. My mate has a similar setup running 308 and 400 of torque if I remember that right lol.

 

[DurkWorks]

And thanks for the help I'll try my connections. But yes it is confusing mate. Even buy another ecu kit and try that.

 

[Damien Wood]

And thanks for the help I'll try my connections. But yes it is confusing mate. Even buy another ecu kit and try that.

No it's a stage 2 map but I now have a hybrid so should push more than 260 out when mapped in again. A stage 1 no mods is around 215 from 180. A stage 2 with K03s and other mods 260ish.a stage 2plus or 3 is with a hybrid turbo aswell. So should be about 300. My mate has a similar setup running 308 and 400 of torque if I remember that right lol.

Oh I see I thought you had a Cupra r. Before you spend more coin I should wait and see if someone can shed some light.

 

[Damien Wood]

Try disconnecting the maf and drive it. See if it runs better, if it does it’s your maf

 

[mty12345]

You have so many mods it makes it difficult to say, but a couple of things come to mind.
1. You don't mention your spark plugs, are you running ones a grade colder? I'm guessing you probably are, but if not then that could possibly contribute to detonation.
2. If you're running such high boost, then i'd have to wonder if your 386cc injectors are maxing out trying to provide enough fuel. It's possible that a weak mixture is causing your det issues too.

I think your best course of action is to either run some logs with vcds and post them here, or take it to a specialist like Bill@badger 5.

 

[DurkWorks]

With vag com does it record duty cycle for the injectors? As that will show if injectors are maxing out. And my plugs are bkr7e. Thanks for the reply mate.

 

[DurkWorks]

You have so many mods it makes it difficult to say, but a couple of things come to mind.
1. You don't mention your spark plugs, are you running ones a grade colder? I'm guessing you probably are, but if not then that could possibly contribute to detonation.
2. If you're running such high boost, then i'd have to wonder if your 386cc injectors are maxing out trying to provide enough fuel. It's possible that a weak mixture is causing your det issues too.

I think your best course of action is to either run some logs with vcds and post them here, or take it to a specialist like Bill@badger 5.

With vag com does it record duty cycle for the injectors? As that will show if injectors are maxing out. And my plugs are bkr7e. Thanks for the reply mate.

 

[mty12345]

I'm not sure it shows it duty cycle specifically, but you can log RPM and injector on time and work it out from that easily enough. Also it will show lambda values, (requested vs actual) so that will show a weak mixture too.

 

[DurkWorks]

I usually use the snap on diagnostic machine. Hopefully vag com is in a lot better detail. I will try and do a log using vag com and post the results. Never used it before so might be fun.

 

[DurkWorks]

I'm not sure it shows it duty cycle specifically, but you can log RPM and injector on time and work it out from that easily enough. Also it will show lambda values, (requested vs actual) so that will show a weak mixture too.

I have kept the same ecu the whole time. Wonder if I should change it. Does anyone know what bits I need to do a ecu swap. For example key and ecu and.......? Or is it better to buy and ecu and get the immobiliser taken out of it? Do the ecus on the auq leon ever fail?