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1998 V70R Low Boost

Long-term I'd be tempted to ditch that intercooler for an aftermarket unit or a good looking example from the JY.
 
You should do that with the rest of the system.

I have a few times now; I have not been able to identify any more leaks.

Also, a little update. I got in the car a few moments ago after it was sitting for a few hours and for some reason, the first time I got on the gas hard, it boosted to 6psi. After hitting the gas again, it was right back to 3-4.
 
No change in the rev range, it's 4psi constantly. Soon as I floor it, it'll go to 4 and stay there until the gear change, then go back to 4.

Something else also just kind of hit me last night. My car has the resistor mod done for the secondary air pump system in the ECU, as I found out when I went to go do it myself last week. Since I saw the resistor I just put the ECU back in. Last night I was getting a code pertaining to the secondary air pump... Which I shouldn't be getting with the mod done. Part of me wonders if the mod could somehow be affecting my ARD tune. If it wasn't accounted for when the tune was made wouldn't it mess with my system? Possibly limiting boost?
 
Well today I tried to drive the car up a hill... It was boosting around 2psi and it was so slow that I had to throw on the hazards and let people pass. Maybe 30mph tops. Could I have a fuel problem maybe?
 
Have you checked pressure at the rail? I don't know if low pressure would limit boost but it would limit RPM. One of my buddies runs a newer v70R and said he had similar problems, turned out to be a boost pressure sensor.
 
Also, can someone confirm my routing to the TCV? Red to compressor, blue to intake hose, yellow to wastegate, right?

30670449-vacuum-lines.jpg
 
Have you checked pressure at the rail? I don't know if low pressure would limit boost but it would limit RPM. One of my buddies runs a newer v70R and said he had similar problems, turned out to be a boost pressure sensor.

I have not yet tested my fuel pressure from the rail but I plan to do it today. As far as a boost sensor goes, I'm not sure where mine are. Or if I have any. Could this be my problem and could anyone point me in the right direction as of their location on the car and how to troubleshoot them?
 
Something else also just kind of hit me last night. My car has the resistor mod done for the secondary air pump system in the ECU, as I found out when I went to go do it myself last week. Since I saw the resistor I just put the ECU back in. Last night I was getting a code pertaining to the secondary air pump... Which I shouldn't be getting with the mod done. Part of me wonders if the mod could somehow be affecting my ARD tune. If it wasn't accounted for when the tune was made wouldn't it mess with my system? Possibly limiting boost?
Interesting possibility...I'd see if you can find someone with a 98 x70T5 or V70R ECU to loan you to see if that is the root of the problem. Try asking on Volvospeed or Swedespeed.
 
The SAS mod/fault shouldn't limit boost, my '98 XC still boosts fine with the pump disconnected/no mods to the ECU.

'98 cars don't have a boost pressure sensor or fuel pressure sensor.

I would suspect fuel pressure, the MAF, or a clogged cat at this point. Did you replace the fuel filter as part of your stage 0?
 
Solved everyone! Clogged cat, that's all it was. VERY clogged cat. I got it fixed today, but I'm still struggling to fix my P0505 and P1505 codes. Both have to do with my IAC. I have replaced it 3 times and nothing has helped. The car idles too high when warm, and I'm thinking its a wiring problem. The PO had the IAC connected directly to the negative terminal on the battery, which didn't help anything, but I re wired it back into the original harness. I'm wondering if the harness has an issue somewhere. Maybe not getting 12v? If I run 12V to the IAC from the battery, might that slove my problem?
 
Are you sure the TPS and IAC plugs aren't switched? They're close together and the same size.

I wouldn't try running power directly to the IAC.
 
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