Under boosting 1997 850 t-5 after replacing parts

buggzz · Post by **buggzz** » 10 Apr 2023, 23:07

Okay I bought the car year and a half ago, great car. But soon it has developed a under boosting problem I replaced the tcv with the ipd tcv as well as silicone hosing, and also the cbv. Im utterly lost the car has close to 200k miles, great condition no check engine light. I may be thinking its a clogged cat but I haven't checked. I've hit a dead end. If any of you can help please and thank you!

Post by **scot850** » 10 Apr 2023, 23:37

When you assembled the IPD TCV, did you screw the 'front' leg all the way home? If you did you may be getting little or no boost. Stupid design. If you screw the front leg in more than 3-4 turns it crushes the little filter and jams the valve.

Neil.

buggzz · Post by **buggzz** » 11 Apr 2023, 13:56

scot850 wrote: ↑10 Apr 2023, 23:37 When you assembled the IPD TCV, did you screw the 'front' leg all the way home? If you did you may be getting little or no boost. Stupid design. If you screw the front leg in more than 3-4 turns it crushes the little filter and jams the valve.

Neil.

When I installed the IPD tcv, I installed it first then I sent it to a shop to look at the turbo since I wasn't getting as much boost, and they might have screwed it all the way. Any way that I can revert it? Thank you

Post by **scot850** » 11 Apr 2023, 17:36

Nope! Once the filter is crushed, it is done. I got a free replacement from IPD after complaining about their info not stating the issue. I have also told them a number of times to fix their instructions.

You could try removing the filter and see if at least it makes a difference. I would check if the arm is turned all the way in first. If it is not then you may have dodged a bullet. If it has been then removing the filter may be the only way to see if it will move. You and check if the little valve move. The standard TCU operated up to around 12-14psi, so if you have the original or can gt one from a junk car it may be worth trying to eliminate it as an issue.

Neil.

buggzz · Post by **buggzz** » 13 Apr 2023, 17:29

Well that's a nice feature. Thanks for the help I'll try to see when I can go to the junkyard next to see if I can even find a turbo.

Post by **scot850** » 13 Apr 2023, 17:36

I have several of the 98- TCV's from junkyards, but I seem to recall the 850 turbo ones were different shaped. Not sure if that makes any difference?

Neil.

buggzz · Post by **buggzz** » 17 Apr 2023, 14:06

So I found one tcv and I was testing it out and, I know have a ton of turbo lag, It now spools at normal pressure around 4500 rpms, it used to be around 3700.

Post by **Sveedy** » 17 Apr 2023, 14:49

Maybe adjust the wastegate.

Post by **scot850** » 17 Apr 2023, 17:36

So you are at least getting boost, but not where it should be in terms of revs? At least a step in the right direction. Sveedy knows more about these things than I will ever know so I would follow his suggesiton.

Neil.

Post by **scot850** » 17 Apr 2023, 17:43

When I had a problem with the IPD turbo TCV, I contacted them and complained about the issue. In your case add you gave it to pros to install and as there was nothing to say different, they cranked that front leg in jamming the valve. Also mention you only found out about the problem doing that obviously after the event.

Which TCV did you use? The rectangular shaped one from a V/S70 or the round one from an 850 like this link?:

https://www.ebay.com/itm/181437504669?_ul=CL

Neil.