I would try to put an aftermarket gauge in to watch the boost and know it is correct.

 

As I wrote before, I always got fuel-cut with manual boost controller. While with turbo control valve (TCV) there was a overboost problem. So I checked hoses connected to TCV and replaced one from TCV to wastegate (5mm instead of 6mm) and installed TCV back (instead of MBC). But there occured another problem: turbo does not boost more than 0.3 bar. I replaced TCV with another one, but situation did not change. Max boost was 0.4 in 2nd gear (while ECU remapped to boost 0.9). With MBC boost is ok. Diagnostics do not show any faults. Where could be a problem? Have any ideas? Maybe more tight hose is causing more pressure to wastegate?
Another question would be: can not reseted dtc fault 4-1-4 (overboost problem) cause fuel cut with mbc? That means, if I have this fault with TCV and I install MBC, can this be a cause of fuel-cut?
Thanks for responds.

 

Are you sure all lines are connected to the TCV correctly?

 

Lines are connected exactly as in shown in this picture: http://media.photobucket.com/image/v...gs/Turbo-1.jpg otherwise there would be overboost.

Also removed hose from wastegate, and turbo boosts perfectly. Put it on back - no boost again. Could there be a cause in ECU?

 

It is possible do you have a stock ECU you can drop in to test with?

 

Next week I will get one and give feedback.

 

The hose from the middle of TCV I connected to a big hose from air filter (where there is a place for a hose just after MAF). Is that right? Maybe a pressure from that hose is affecting wastegate?

 

Why do you want the TCV in the vacuum circuit?

If you take the time to adjust the MBC to just below fuel cutoff it should do the job. I had a problem with my TCV (due to ECU) which caused me to hit fuel cutoff so I put in a $20 MBC and adjusted to just below fuel cutoff and the car runs great.

Also, if you re-chipped why do you have fuel cutoff? shouldn't it have been programmed out in the new chip?

 

Because I was getting fuel-cut with mbc (adjusted to 1 bar)even though ecu was programmed to 0.9 bar.

 

+1

A reprogrammed ECU should not have fuel cut-off. If your cutting out at high boost you may have a spark issue.

 

isn't 1 bar a higher pressure than 0.9 bar?

0.9 bar = 13.1 psi
1.0 bar = 14.5 psi

the MBC needs to be adjusted to <= 0.8999999999bar so the ECU doesn't cut the fuel.

 

Higher, but fuel-cut level is pushed further after chipping.

 

Tried another ECU, but situation did not change - no more boost than 0.3 in 3rd gear and almost 0.4 in 2nd.
No ecu faults again, no dashboard lights. Maybe there is a trouble with lambda, rpm sensor or maf?

 

Well, tried to change connection order of hoses from TCV (not as shown in that scheme http://media.photobucket.com/image/v...gs/Turbo-1.jpg , hose from turbo connected to 3rd place, hose to wastegate to 1st, the middle one left as it should be). So I get overboost to 1.2 bar and get service regime to 0.3, then 1.2 and 0.3 again (fluctuating boost (dtc code 4-1-4). No fuel cut, everything is controlled by tcv.
If it isn't correct connection should tcv be able to reduce boost to 0.3 or less as in my case or it should overboost to fuel cut?

 

Up...

 

Does anyone know should wastegate be adjusted after chipping and higher boost?

 

Usually it should be left alone. Some will adjust it. When people adjust it they usually go like one turn. It will be at the point where the rod attaches the hole will be half way over the pin. You will have to pull it slightly to get it on the pin.

 

Well, after numerous tries with another TCV, different change on hoses conection, TCV was connected well. Turbo boosts, but overboosts. So I get automatically reduced pressure while overboosting and fluctuating boost while riding (1.2-03, 1.2-03 and so on).
ECU is programmed to 0.9, but it seems that ECU does not see that boost is coming and do not prepare to reduce it and overboost occurs, then ECU drops pressure down. And again it boosts, overboost, drop down.
As wrote before, TCV is ok, hoses are removed and ok, with stock ECU no problems, boost hold stable, no more than 0.5-0.7.
ECU does not give any faults in A2 except 4-1-4 (overboost).
Where could be a problem? May it be fault in new ECU map or any other cases?

 

what turbo are you running. If it is stock (I did not read the whole thread) is it possible the turbo is maxed and it is causing the fluxuation you are describing? It might be a bad chip burn?

 

Turbo is stock, it is not maxed.