ok, last post for tonight I promise.

I've lost a lot of power. I can here the turbo's spinning up. (well, I can here at least one spinning, hard to hear both) but the car just doesn't go anywhere.

I replaced the TCV with the IPD unit, same symptoms.

I've replaced all the vac hose's, I now get a sweeet 20 inch's at warm idle now ( I did before aswell, so it never was a vac leak)

On my boost guage it shows an average of 5 psi, very early in the rev range it might spike to 7, and at the end of the rev range its as low as 3.

I also replaced the spark plugs with the copper ones from IPD at the same time, just incase, no difference.

I'm just trying to get this thing back to factory, its fast neough for me stock, but I'm just having so many problems at the moment.

Thanks for the help guys,

Stu

 

Check all the air hoses to make sure you have no cracks and the clamps are all tight. Also recheck the vacuum hose routing to make sure you've got it all hooked up correctly. If you get the hoses to the TCV wrong, the turbos revert to a "default" mode that only gives about 7 psi instead of the normal 12.

 

Cheers mate, I'll check them today, but I'm pretty sure I got them right.

does the computer retain the default setting? do I need to disconnect the battery to get it to drop this default mode? or will it re-check it when the car starts again?

Stu=

 

I believe it's just a spring on the wastegate arm. I read about it on another forum. Maybe Tech can chime in here and confirm or deny?

 

99 S80 t-6. While driving without any warning engine stop without hesitation etc.. One key and engine will start again like nothing ever happened. Engine is usually running for a while. Not cold. Like today this happened 3 times already. No messages, NO CODE. Engine was recently changed for one of 65000 miles. Car runs great. This problem was there before the engine was changed. Looks like electrical issue. Any idea!!!

 

Maybe fuel pump.

 

ok, managed to do some tsting at the weekend.

My wastegates have no spring, is that correct? I undid the clip holding the rod on, and it moved freely. There was spring in the rod though.

I did a test and the wastegate actuators started working at about 6PSI, which I think is right from what I've read.

I've got a new TCV on there, the one from IPD, and I'm getting the same symptoms. I've replaced all the vac hose's with the ilicon stuff from IPD aswell. I'm geting 20 inch's of vac at warm idle.

What else could it be? it seems like the TCv is constantly open, hence why I'm only getting about 6psi boost pressure, but why could it keep it open contantly?

One thing to note, I've got a laptop based OBDI scanner, which I plugged in. It detected the boost pressure sensor but I get no reading from it, nothing at all. I took the sensor out, read the resistance over it and then applied some pressure and the reading did change, so I thought it was probably the software, rather than the sensor but maybe??

Cheers for any help guys, slowly getting to the root of the problem.

Stu

 

ok, some more info.

I put the pressure gauge on the outlet of the TCV to check to see if the engine was trying to open the wastegates, and it wasn't. So its not wastegates or TCV that are causing the problem.

Could it be the throttle boddy? we don't get the extended warrenty on ours. Is there a way to check? manually open the throttle and read the resistances? does anyone have a pin out of the throttle body connector?

Its accelerate happily up to about 3k, then starts playing up after that. Feels like power drops and then doesn't pick back up properly. Some times if I release the throttle then plant it again, it seems to pick up better.

stu

edit : I think I read somewhere about the colour of the sticker on the throttle body can tell you what version it is, my sticker is white.

 

If you have nothing at all trying to happen under boost if it is never pulling the boost back then you might be hitting full boost then cutoff or something like that.

If you just put the guage in a vacuum source how much boost is it building?

Volvo didn't release any numbers for testing the throttle body.

It usually sets a ton of throttle codes when it goes bad.
White sticker is original.

 

If I put hte pressure gauge on the inlet manifold, I get about 5-7 PSI, but its very inconsistent across the rev range, smooth up to 3000-3500, then drops and build again. Power drops very suddenly, then builds again.

I can hear the turbo's spooling up.

Will those throttle body codes throw a check engine light?

Has anyone ever tried taking a TB apart and cleaning it out? not just the valve and throat, the sensor's, etc

 

Yes it will throw the light on.
If it goes erratic then the valve might be doing its job.

 

ok, I' have no check engine light

There is no pressure going to the wastegates to open them up, so thats not the problem (which is what I suspected)

So ignoring turbo's, what else could cause sudden lose of power, above 3000 rpm? no check engine light, so it seems its unlightly to be the throttlebody. What about the Air flow sensor? could that do it? is there anyway to check?

Stu

 

Plugs,coils,Maf,o2 sensor. They could all be causes.

 

ok, plugs are fine only just replaced them, is there a way to check the rest without buying new ones?

Poopbunny, don't suppose you want to lend me your MAF for a bit do you? hehe