rpm problem bcb engine

[leonbcb]

hello guys

i have problem with the rpm of my leon with the 1.6 bcb engine

without reason the throttle starts open/closes and the rpm form 600 to 1300 and after some seconds stops

throttle body cleaned and aligned
egr valve cleaned and aligned
canister motor changed
fuel filter changed
no fault codes

anyone can help me?
the car drives well most of the time

 

[leonbcb]

update:

o2 sensor changed
one black box behind the engine with two wires on it changed ( i don't know the part name)

 

[leonbcb]

Bump

 

[leonbcb]

update!

engine flashed and cleaned
cylinder head check with camera

all fine

 

[Jirwin]

You've cleaned and alligned the EGR but have you tried a new one? Also maybe MAP sensor?

 

[leonbcb]

Egr tested with vagcom and is working also map
Sensor changed

 

[Jirwin]

My EGR showed as fine on Vagcom but had failed internally. Is there anyone near you with same engine you can try a quick swap with, its only a 10min job to switch them out. Also take out the pipe between the EGR and Throttle Body, it may have cracked, split or be properly gunked up, mine was fairly dirty at one end. Its fairly fiddly to get it out but may be worth a shot

When you say EGR tested with Vagcom do you mean fault codes read, as one of the 8 tests the car does every now and then or Logs run and checked?

 

[leonbcb]

no i can't find one with the same egr i have many vw engines for spairs but not the same egr.

if you check the vagcom there is a test which turns on the egr so when i remove it to clean it i run the test and the small piston it was moving up and down , also there is no fault code for the egr

 

[Pyro]

are there any codes showing at all have you tried a new maf?

 

[Jirwin]

There is no MAF on the BCB engine

Does the EGR pass the other test? There are about 8 tests that get reset when you clear the fault codes, oxy system, egr and a few others, I can't remember where you'd find them but that will probably let you know if its working. It takes a while for the car to run through them all and sometimes will start doing them again so it looks like its failed. Mine would pass that, the EGR would open and close and it had no fault codes but was still knackered.

Other than that I'm out of ideas, sorry

 

[Pyro]

my bad