MVS Contributor Sledddriver goes on an multi-month blistering repair & fix odyssey, taking his 1998 V70 T5 from the edge of roadworthiness to 100% functional and reliable… all for not even $1000. This is Stage 0 and way, way more. Following up on Tryingbe’s theme [of restoring to 100% a P80 Volvo], here’s a list of sled-work […]
Curious if your Volvo’s wastegate is properly configured? MVS Volvo Forums Contributor sleddriver documents adjusting the wastegate. He finds it off, and corrects it. Often owners “give them a few turns” to keep the turbo spinning in more situations, which reduces turbo lag when you floor it. This normally doesn’t cause damage because these Volvos are […]
Boost pressure issues seem to be the #2 issue in the Volvo Performance world beaten out only by vacuum leaks. Boost pressure control in the 1994-1998 models is a pretty simple system but for the ECU to manage boost correctly it relies heavily on known base values and settings. If these settings are off or if there are mechanical issues then the boost control system can be out of whack.
Underboost is a condition that can be caused by several issues including: Bad TCV Bad Turbocharger Failed boost sensor (for models that have them) ECU seeing overboost and cutting back until reset and condition remedied Failed MAF (for ecu’s that use the MAF to determine boost pressure) Failed atmospheric sensor ( again for those that […]
Wastegate Settings – Numbers and Theory The idea here is to assure the wastegate valve remains closed until the wastegate experiences the preset pressure in the VADIS doc above. Anything higher than the Vadis pressure and the wastegate valve shoud move/open. I have a magnetic dial gauge I use to monitor the wastegate valve action […]
Warm Idle: 18 inches of mercury vacuum.
Cold Idle: 16 inches of mercury vacuum.
WOT (Wide Open Throttle) 2,000 RPM: ~5 PSI boost.
WOT 3,000 RPM: ~15 PSI boost.
75mph @ 3,000 RPM: ~10 inches of mercury vacuum.
Between Shifts: 0 (atmospheric) due to the bypass valve venting manifold pressure to keep the turbo spooled.