VRS turbo woes :(

[SyVRS]

After replacing my turbo with a reconditioned unit standard kkk I just can’t seem to get it running right at all.

 

The boost seems to come in late with a big spike around 3000rpm in third gear.

 

In first gear boost doesn’t really kick in as the engine revs up much faster and it’s time to shift gear before you produce boost. Same in second but not as bad. 

 

Cars seems very smokey under hard acceleration compared to before but this clears once the boost comes in (lack of air, turbo lag?) and it’s fine whilst doing cruising speeds on the motorway and around town. Mpg is also ok on a motorway run but probably not as good as it should be round town.

 

 

Ive done 3rd gear WOT runs and logged it. I’ve set the Actuator up the best I can using vcds to adjust the stop but I can’t seem to produce the figures which are commonly stated on here. 

 

For example:

i cant seem to produce the 130-150mb pressure difference when setting the stop the most I can get is 120mb (960-1080)  if i wind it out anymore I can get 132mb (960-1092) and the veins jam. If I wind the stop either way of the point I have it set now the pressure either drops lower or goes up to the point of jamming. 

 

I’ve tried shortening the rod to bring the boost in quicker but it seems to make no difference other than causing the car to overboost massively like 1.9bar before the vacuum cuts it off and then it comes back down and meets requested boost and stabilises and the duty cycle is around 63% at 4000rpm butndont want to shorten the rod any more to bring the duty cycle up due to how high the boost shoots up before coming back down.

 

All boost pipes have been replaced for hard pipework and a FMIC after having leak problems after fitting the recon turbo but will check for leaks again.

 

Ive had a mity vac on the vac line to the turbo and checked for leaks there are none and the actuator moved freely up to the stop. 

 

My next point of call is to check all vac lines from the vac pump as I’ve noticed a hissing noise from the side of the engine where the exhaust on the vac pump is but if there was a problem I would expect to feel on the brake pedal?

 

Could it be a fault with the MAF sensor giving a dodgy reading?

 

The n75 valve seems to operate the actuator ok but maybe it’s not working to it’s full potential how can I check this? I have noticed that it buzzes quite a while after turning the ignition off and the duty cycle at idle is really low about 23% and I was told it should operate no lower than 30% is that correct? 

 

I don’t know if the car has been mapped by a previous owner and if it had would it cause issues like this when trying to set up the turbo?

 

there are no codes stored in vcds and no warning lights on.

 

im getting fed up now just want it running sweet again like it was before the turbo went bang. Is there anything else I’ve missed which could cause this that I can check?

 

Any input is greatly appreciated, if any of the information I have written is incorrect please feel free to correct me or if any more information is required please ask, I can supply graphs of my logs if needed. Thanks in advance. 

 

*note it’s an ASZ engine 

 

Edited 10 August, 2018 by SyVRS

[SyVRS]

Update for anyone interested

 

fixed this now the actuator arm was far too short think the issue I had was because the turbo had been set up for a standard car and mine seems to have been remapped from the previous owner so I had some messing to do to get it right.

 

I disregarded the figures which I read on here for setting the actuator and just made sure my required and actual boost were the same. Pulls like a train again now.  Happy days.

 

 

 

Edited 12 August, 2018 by SyVRS