#5592, "MS2 boost dropping above 6k rpms" Oct-15-12 11:22 AM by SilvrEclips
Recently I sold my MS1 unit and started clean with a new MS2 unit I assembled. Unit has worked flawless until I started to really tuning boost portions of the map. Here a run down on the board
MS2 v3.0 running gslender v2.8 firmware. (also tried 3.2.1) IAC mods Launch control Fan control Meth injection Boost control Tach output
The issue is that during a pull, the map sensor gets noisy as boost builds. Its set to around 10-12psi, but as soon as I get to 6k boost drops down to about 8-9psi and just floats around there. So far I have tested the following things:
-Confimed boost reading with 2 mechanical gauges (boost is not dropping off only MS claims it is.) -Changed to a different map sensor -Added a resistor pack to injectors to run them as High Z -Grounded the ignitors outside the board on their own ground -Tried grounding MS to engine block, battery, cleaning the existing ground -Tried running a separate 5v reg just for the map sensor -Tried unplugging the VSS and tps and any board mods that run off the 5v proto area. -Checked over the map circuits to verify good connections on the board with a DMM
Its so weird bc its happens EXACTly at 6k everytime. At part throttle out of boost above 6k its fine, but as soon as I hit the gas hard and boost builds it goes crazy. I tried replicating conditions on the stim with no success.
The only thing I have seen that is weird is the 5v reg voltage increases as boost/rpms increase. Here a vid of the DMM checking voltage from the 5v proto area at partial throttle and then hitting the gas. You can see how boost causing the voltage to increase to almost 5.1v. The second video is showing the mech boost gauge VS tunerstudio and the map dropping out.
This issue is driving me crazy and I have no idea where to look/check next. Any help is much appreciated.
#5593, "RE: MS2 boost dropping above 6k rpms" In response to Reply # 0
I just took a quick look at the log and everything else seems good while its happening, have you tried changing the spark table in that area? Whats the turbo specs? what size is the turbine
#5594, "RE: MS2 boost dropping above 6k rpms" In response to Reply # 1
Im running a holset hy35 turbo. I was running this turbo at 23psi with MS1 before upgrading so its not a mechanical issue. Also both my mechanical gauges show that boost IS NOT falling like MS says.
#5598, "RE: MS2 boost dropping above 6k rpms" In response to Reply # 3
Yea some of the guys on that forum have been trying to help me out, nothing has been effective at solving the problem. Probably gonna call up symtech and might have them test the board out.
