Wastegate Re-Build: Is it a DIY Project?
 

My '86 930 is having overboost problems.

Under full throttle, it pegs the boost gauge, then the 'overboost switch' kills the fuel flow (this is a good thing). I replaced the overboost switch, and the rubber pressure line to the wastegate. Nothing changed. I fear the diaphram is leaking/stuck preventing the wastegate from operating properly. I blew compressed air (~20 psi) into the 'inlet' pipe on the wastegate today, and the air blows right through to the 'outlet' pipe venting into the engine compartment. Even at low pressure, the air blows right through. It didn't sound like anything inside the wastegate was moving. I took this as a bad sign.

I want to know if a re-build kit exists (and what is the part number?), and if it is something I can do myself (in my garage). If not, does anyone know if a specialty shop that I can ship mine to?

Thanks in advance.

Emission, check out this thread. It might help you.

http://forums.pelicanparts.com/showthread.php?s=&threadid=71502&highlight=wastega te

Thanks, I found that thread last night when I did a search before posting.

The post is helpful, but doesn't answer my question if anyone has any experience rebuilding their wastegate, or they know a shop that does it.

As a follow-up:

I was quoted $1,700 for a new wastegate (OEM).

Then, I was quoted $599 for a new aftermarket wastegate (CNC Aluminum).

Finally, I was quoted $450 for a rebuild of mine (OEM).

Luckily, I found a diaphram only (DIY) for about $95 at Imagine Auto. Understandably, I ordered it.

I will post installation pics for future reference once it arrives.

Why don't you just go for an aftermarket TiAL Wastegate (46mm)? It flows more than the 930 OEM unit and is about 1/3rd lighter also. Not to mention nicer looking and made of better/stronger alloys. They aren't that expensive. I use one, which cost me $250USD NEW direct from TiAL :D

That is going to be my fall back. If the new diaphram doesn't work (and it turns out to be something else mechanical with the original part) I will buy an aftermarket unit.

Do you have a picture of yours? How about a part number?

Thanks.

Hi,

Sorry for the delayed reply.

You can e-mail Gregg Jones of TiAL here tialinc@earthlink.net for more product info or go here http://www.tialsport.com/wastegates.htm.

I have the Red Anodised 40mm unit which is good for up to 550-600HP :D

Hope this info helps. They are a VERY high quality unit made of Stainless Steel alloys which are literally 1/3rd the weight of the OEM 930 units and can be ordered with any boost spring desired...