before i get in too deep and try diagnostics with my mapper, i just want to try and figure this out myself, i had my car mapped (simtek), 1.5 bar power map, and 1.2 bar low map, my car now hits 1.2 bar on power map, and 0.9 bar on low map for some reason?, what could cause this?, i am just looking for ideas?, would a boost leak cause these relative figures?, clutch slipping etc?, sensors? header/up pipe leak? ideas please? thanks

 

Sounds like a physical problem. Leaking headers or intercooler pipe would be primary culprits, followed by some issue with the boost control system such as actuator or control pipework.

 

Ask your mapper Sam! Whoever it is, he's just been in there, and will know it better than you do. Plus, you paid the guy, so he'll want to you ask him, rather than start fiddling with it. I know I would!

 

I think it seems physical too, thanks for your reply.
I can hear a tinny sound on idle with my head under the bonnet, like a washer on a bolt rattling, it seems to be coming from near the turbo area, i checked all bolts on headers, up pipe, turbo, actuator arm, etc, still cant find it!, that aside i think my next thing is to strip ic pipework, my only query is that the power map hits 1.2 bar (when it should be 1.5), why would the low power map (should be 1.2 bar) not reach the correct 1.2? if it was a boost leak, or a simple 'mechanical' leak?, you can see what i mean?, if the pipework, or anything else boost related what not holding up to 1.5 bar, should it not hold up to the same level in both maps?

 

Alan, i tried to keep the original post simple and to the point of me trying to sort this, my car was mapped very well, i am just trying to get some ideas up there, my car has had so much work done to it by my non mechanical hands, that it is pretty much definately my fault, for example just after mapping, my front loom melted on the headers causing all sorts of problems, and my clutch seems to have started slippping also!, this thread was just trying to get ideas to satify my curiosity, this car is one of my hobbies.

cheers

 

clutch slipping may influence but usually still makes boost target..

sounds like an exhaust leak..

the boost duty set to reach the boost settings on both maps is going to be effected by the leak.. I would also assume header or intercooler leak.

All the little vac lines on the manifold?

Simon

 

Sorry, I thought scoobynet was the place to come and get 100% accurate answers, and where the posters knew more about your car than the people that worked on it

 

thanks for your reply simon, i will strip down the exhaust system from the heads, inc the turbo, see what i find there, then will move onto the IC.

Hi Pavlo, i am not sure that i understand your last post?

 

Hello mate. I had exactly the same issue. i checked all pipework headers etc.

it turned out that my actuator arm on the turbo wasnt fully located and it wasn't until the circlip on the arm fully came off and i lost all boost that i noticed it.

just my experience

 

Thanks davebeck, you know, my very small tinny rattling sound could be coming from the actuator, this is the area a pinpoint it too!, what turbo was it that it happened to you with?, how do you mean located?, how did yousort it after it failed?
thanks

 

Was on my TD0518g,

basically the circlip came undone so the locating arm wasnt fully in it wasnt until the circlip fell out that i noticed. just replaced the circlip thanks to a mate having one

Im guessing this was my problem because as soon as i replaced the clip i hit full boost again. obviously if the actuator doesnt open fully you wont make full boost.

my next step for you if thats fine is remove all you boost houses on your front mount then put them all back on double checking they are tight and sealed as you go.
if you start the car from cold after run your hands around the downpipe gasket/headers to up pipe gasket(very common to blows) and block to exhaust manifold gaskets. should hear it really if its blowing

hope this helps mate