Fabia VRS Intermittent boost issues...

[NathanWarren69]

Hi Guys,

 

Hopefully you can help here.

 

Currently i'm having an issue where every now and then My Car limits how much boost i'm making which makes the car feel really sluggish. I have connected up my OBD and can see that normally the car makes between 20-23PSI of boost on both the superchrger and turbo but when this issue occurs it sits at 10psi. Almost like a safety boost mode but no errors are displayed.

 

Currently the car has the Forge Induction, Turbo back exhaust with 200Cell Sports cat and a Revo stage 1 remap, Forge Bov Spacer.

 

I'm really puzzled by this as i cannot replicate this issue on demand sort of thing it just happens every now and then and sometimes its just fine.

 

I have checked the boost Bypass Valve that connects to the spacer plate as i have seen a lot about these being cracked sometimes after a remap but this is fine and is working correctly.

 

Before this happens i have noticed the dump valve activates then stops then you only have half boost.  After driving around for a short while it goes back to normal then wont do it again on that journey, or if i restart the car its then fine again.

 

I think it could be the Boost control Solenoid or the map? (Dont think it is the map as this issue only appeared just before Christmas and its been mapped since about july last year)

 

Has anyone else had this issue? Or any ideas what to try?

 

Thanks in Advance.

 

Nathan

 

 

[Ootohere]

So many possible issues there with the mods you have on, 

someone else with a similar set up might be able to advice.

 

Did you fit everything, and how long ago and in what order?

 

 

Getting the REVO map removed would be the first thing i would get shot of,

maybe get a APR stage 1.

 

Could the change have come with the Winter Spec Fuel?

I take it you are running on 99 ron,  and you have good plugs in and these have been checked recently.??

[tattyjay]

Maybe a stupid question but has the car had latest ECU update?

And maybe someone can confirm to me if it is a stupid question because it would overwrite the map if it was updated now?

[Ootohere]

Good question,

A CAVE that was Remapped Stage 1 would no longer be running the Stage 1 Map if a Skoda ECU Update was done on the car.

[NathanWarren69]

The order was BOV Spacer, Map, Intake, Exhaust. IT has the uprated NGK Iridium plugs which I've checked and look fine. Has not had an ECU update since the Map but did have an update before hand And potentially Fuel but did not think they changed it? I always use either Shell V Power or Tesco Momentum. 

 

Its strange how it can go for like a week without doing it at all then just randomly happen, never really seems to last longer than around 5 minutes, and if it does it on a journey it doesnt seem to do it again on the same journey.

 

Thanks for the responses.

[tattyjay]

Is there another strange readings at the same time as reduced boost, such as temperature?

[NathanWarren69]

Not that ive seen, ive been trying to keep an eye on the gauges etc, even run a data logger but it dident show anything abnormal from before or after it happens. Only started happening around December, I will probably try and take it back to the place that mapped it tomorrow to get them to reload the map in case there is a corruption.

[andy3270]

Does it always do it when hot as your car has a similar set up to mine revo stage 1 and a full Miltek system and I found when checking the oil after a run the engine bay was incredibly hot even after 5-10 mins letting the oil run back I spoke to a few people and the best route was to fit a uprated intercooler as the standard one is small and not that effective the results are much better and noticeable gains in power delivery also. Hope you get it sorted out my local revo dealer was very helpfull even though the car was not remapped there with any issues 

[newbie69]

Wow, REVO and a Forge BOV spacer, sure way to get into trouble from the experiences we've heard over the years. The Forge BOV has been blamed for a lot for several boost leaks iirc, you could start from there I guess.

[NathanWarren69]

I had abit of a search last night and couldn't see people having issues with the spacer plates, Any idea what the issues are? Im thinking that in the morning i may remove this and put it back to stock to see if it makes any difference. It does almost seem like a boost leake tbh its just odd how its only every now and then and not permanently. Had the map removed today as a test and it still does it just as bad so I've had it put back on

[newbie69]

Sorry it's been some time (2+ years) since these threads were created, they must be in this forum though. The issue was boost leaks and the Forge BOV was what was causing them if i recall correctly. Besides, from what I've read mainly in FB groups about the 1.4 tsi, the BOV adjustment is rather important for proper operation and people have been experimenting quite a lot with it. I think it makes sense to remove it and see if your issues persist or not.  

[PaddyVRS]

I have had similar problems before on various occasions at differing states of engine temp and driving conditions. I don't have any exact measurements of boost unfortunately but on one occasion the car would not pull past 4000RPM in 4th gear, just got stuck. Touch wood I haven't had any issues like this in ages, nothing was found during service checks. 

 

I still have no idea what caused it, on one occasion I had no boost at all. Not even from the supercharger! All other instances were supercharger fine and once it reached turbo only it just died. No lights, no faults and no solution was ever found. If it happens to me again I will have to investigate further but for now I am just leaving it be. There are so many sensors and valves that can possibly cause issues with the boost range it could be a long winded process, especially if it is not happening consistently. I will try upload an extract from a VW pdf on the TSI engines which gives good descriptions of all valves, solenoids etc which could be causing problems

Edited 16 January, 2015 by PaddyVRS

[PaddyVRS]

Hopefully this link will work, file was too big to upload here. 

https://drive.google.com/file/d/0B3rsCZW4C8NoTTZCRDd6eUFnQWs/view?usp=sharing

[NathanWarren69]

Thanks for the input guys. I dident get a chance to remove the spacer this morning. so will try again tomorrow, after lots of looking around it looks like it could be a bad Boost control solenoid and where this is failing the car resorts to using waste gate pressure of 10psi rather than the 20-23 that it should be running.

 

I have ordered a new one and its due to arrive tomorrow, once this is fitted and the spacer has been removed ill report back with hopefully good news!

 

If the Boost control Solenoid resolves the issue i may also look to upgrade the waste gate actuator to prevent further issues and to install a full recirc valve to replace the one VW provide for the engine which i think could also be failing.

 

This morning i decided to open the bonnet and rev the engine abit and listen for noises. if you rev the engine so it comes on boost its not until it gets right down in the rev range till you hear the diverter valve click shut. Worried me that its making this clicking noise as ive never heard it before and wondered if its getting stuck open etc?

[NathanWarren69]

Even only having 10PSI of boos the car is still pulling all the way through the rev range in any gear just not quite as 

hard as it would with full boost