Have You Lost PSI?
MadeInJapan » My turbo has lost boost. I have an upgraded IPD ECU on my ’98 S70 T5 and was boosting at 15PSI and peaking at 17 right before the TB incident. Now I’m back at stock…10 and peaking at 12…so I put in the original ECU and I get the same numbers, so I know it’s not the ECU (or at least IPD tells me it’s not- these don’t just lose programming). I have checked all turbo hoses, vacuum hoses, TCV (even swapped it out to see if there’s a difference) and no change. I’m running Dino oil for another 400 miles and I’ll switch back to synthetic but don’t think that would make a difference. Basically, besides what I’ve mentioned, nothing has changed. They didn’t even unhook the battery to do the engine work but I did and reset adaptives hoping this would cure things, but it hasn’t. The only part of the engine that was rebuilt was the top half with intake valves replaced. What could be going on here? If anyone knows, I’d appreciate you posting.
How to Isolate Low Boost Problems
phils94850 » “Usually” if your wastegate is stuck open you wouldn’t get 12psi. So, id say thats not the prob. but, what makes me wonder is when you disconnected the vac line to the wastegate why you didnt get more than 12psi. When i disconnect mine and i have a stock ecu i can get 15psi very easy. I still think your problem is somewhere around there ( basically a mechanical prob. )
Im assuming you disconnected the correct line.. my vac lines have been replaced so im not sure the color code anymore, but, its the one easiest to get too and it comes off the wastegate nipple that sticks up.
here is a pic of the hose you need to remove to test the wastegate. I circled it for ya. Just be careful, cuz you’ll have no control over you boost and can blow a motor.
