• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

1998 V70R Low Boost

V

VolvoPrince

New member
Joined
Feb 10, 2016
Location
Phoenix
Differing from my redblocks, I just picked up a 98 V70R. Right now I can't get it to boost past 4psi. It has the ARD Green tune as well as a full stage zero. New TCV, Bypass Valve and spring, vacuum tested wastegate, adjusted WG actuator, all new vacuum lines, and tested for boost leaks. I found a small crack in my intercooler which is now fixed, but it hasn't helped my boost problem at all. The only leak I hear is from the intake hose going to the turbo, but this won't affect my boost, right? Intake sucks, not pushes.

The turbo shaft feels fine, not too much play and spins freely. Sometimes when I reset the ECU I can get it to boost around 5-6psi, but it stops doing that after a few minuets of driving. What do I do now?! I'm getting so fed up.
 
Have you checked for fault codes? Are you sure the TCV hoses plugged into the correct ports?

Though I never had any issues with ARD tunes, I'm aware that others did have issues with them. Do you have a factory stock ECU you could pop in for comparison of boost levels?
 
So I have fixed the leaks from the intake. I don't have a stock ECU to test further but I do believe it is an ECU issue. I rest it and it will boost 5-6. If I let it go a bit I drops to 4. If I mess with the TCV and other connections involving boost it drops to 2 psi. And then I can't get it back up to 5-6 without resetting. Very strange. Does anyone have a stock Ecu I can buy?
 
And all TCV ports have been right. As far as codes go I'm throwing P0505, which I can't get to go away. I replaced the idle control valve twice and cleaned the throttle body. It idles kind of high (1100-1250 it seems). I wonder if this has anything to do with my boost issue... I'm a massive noob when it comes to turbos.... It's my first one, so excuse my ingnorance.
 
Yeah, that's not right. The idle should be around 850RPM. Is the throttle cable adjusted properly? There might be other vacuum leaks too. Are all of the intercooler couplings good? How's the one that connects to the throttle body? Those are notorious for cracking where the IAC hose is molded into the coupler.
 
the boost is controlled by the ECU, to do this it needs to be able to control the wastegate. For this it uses a (Pierburg) boost solenoid valve.
file.php

Is that thing present in the enginebay and hooked up correctly? (hoses, connector), no leaking/ dry rotted/ torn hoses? and is that solenoid valve actually opening and closing if you put 12V on it?
If it is stuck in the open position the engine will only use the base boostlevel that is allowed by the weak spring inside the wastegate actuator. Result: low boost.

another well known issue on older mitsubishi turbo's is cracking of the wastegate port, i have seen it on tdo-13, 15 and 16 turbo's, if left for to long eventually the wastegate valve and valve-seat area will get damaged as well and the turbo will no longer be able to make boost at lower and mid revs because a lot of exhaust gasses go through the wastegate instead of through the turbine. End result: low boost on all but high revs.
 
The tcv will wear out over time as well though he says it's new. In fact, nearly every rubber or plastic turbo related part is probably worn out on a '98 Volvo R.
 
Thanks for more info guys. As far as the idle goes I have replaced a few hoses that were soft, not split or cracked. This included one intercooler hose. I have checked the rest multiple times; I've been getting go fed up that I have been taking apart all of the hoses, inspecting them, and making sure they are all put on right and tight. TCV is good, I have replaced it with a new OEM and and IPD one. Right now it has the OEM on it. All of the other hoses to it are new. ALL of my vacuum hoses are new, in fact. I replaced them all. As far as the wastegate goes, I pressure tested it a few time and got it to open around 4 psi. I know for a fact that the wastegate isn't the problem since I have taken off the hose to it and let it run. This should result in boost spikes and high boost. Yes, I know it's dangerous to do, but it hasn't made any difference. I'm still staying in the 4psi range.
 
And even at high revs I'm only making 4psi. It's the same in all gears and all rev ranges. I can not find any more boost leaks either. Bypass valve holds vacuum as well. I let it sit over right and it hasn't let any go.
 
VolvoPrince said:
I used some very good glue, and it's not leaking at all anymore. For sure.
Click to expand...

Most people either take their intercoolers to a shop to be brazed/TIG'd and then be pressure tested. There's no way of knowing for sure unless you have directly pressure tested it and the intake tract. Assuming usually creates more problems. Have you checked the wastegate actuator?
 
I have pressure tested it up to 20psi by blocking the bottom and hooking my boost tester to the top, intercooler is not leaking anymore for sure. I have checked the actuator, yes.
 
You must log in or register to reply here.
Back
Top