Not Hitting Tuned Boost

[PaulTF]

Hi all,

I have a 2004 XR6T with a BFMKII motor that has a flash tune (tuned on dyno by a shop in syd) that I've run both the included 8psi and 11psi tunes on the XCAL3 that came with the car. I started to feel that the car would pull harder every now and then and be sluggish at others on both tunes. I have since installed a boost gauge to monitor the inlet manifold pressure to give me an idea of what could be going on.

11psi tune - First time I boot it, the boost runs up to 14psi and then settles to stock boost (6psi) and then maxes out at 8psi after that. I also notice that in slow traffic or drive-throughs the temp gauge rises to a bees d!(k below half way.

8psi tune - prefers to run at 6psi, until I do a rolling wot and it will boost up to 8psi. the temp gauge does not run as high as the 11psi tune.

I am also slowly losing coolant. It has never gone below min however.

I'm hoping its just tune issue... Looking for some ideas on what the possible issues could be so I can start fault finding... got a lot of experience with N/A however this is my first car with forced induction...

Any help is appreciated

[phantom xr6t]

loosing coolant wont be a tune issue, get the radiator pressure tested. as for the boost problems could be any number of things, start by changing fuel and air filters, are the coils ok and are the spark plugs in good condition and gapped right for higher boost (around .7-.. check for leaking hoses do the boost solenoid maintenance ( do a search in the forum), checked for error codes

[PaulTF]

Thanks mate. Planning on doing the boost solenoid maintenance on the weekend. I'll also check the plug gap. Checked for error codes = none. Filters are clear.

Just killing my head cause it holds stock boost perfect

Thanks for the info and ideas

[FiftyOne]

Sounds like a sticky actuator

[JVK]

Sounds like the duty cycle for the boost control solenoid has not been set up correctly on the tunes.

[PaulTF]

Thanks for the info, hoping it's only a tune issue. Gonna pull some parts apart over the weekend and get to know her a bit more intimately

[PaulTF]

Update: (Knock on Wood) - noticed white stains on the coolant reservoir... top where the cap goes in, stained green... caps gone :( Thought may as well replace the whole reservoir (as nutters do). Coolant loss gone. Not starting to overheat on either tune.

Funny too, the boost seems to be coming on better and hitting a higher mark (closer to 11psi on the 11 tune and holds 8psi on the 8psi)

However not completely happy with the overall boost performance. I will do the solenoid maintenance and post an update once complete.

Out of curiosity, anyone got an idea if the car will roll back the boost to reduce heat/danger to the turbo if it detects a pressure problem/inefficiency in the whole cooling system? Just one idea...

Just odd if so, cause no faults came up in my check and no limp mode either...

Thanks for all the replies so far

Edited 23/07/15 09:10 AM by PaulTF