Hey guys, a buddy of mine developed a problem recently, but he's having trouble registering here. Anyways, the boost gauge shows 11 psi, but the car doesnt accelerate like it used to, and the lag (14B) has increased (full boost acheived at 4000rpm), and when he shifts gears, theres lots of lag again, and he has to wait for the turbo to spool, when before, it was almost instant.... He says it happened almost overnight. He says he tested the compression and it was perfect, the timing, the grounds, the ecu caps and it was all perfect, vacuum leaks as well, cat is not clogged. I suggested a boost leak because my GF's car experienced the same thing, and it ended up being a loose intercooler hose. In his case, its different because you can see the boost rise, and you can hear the turbo, but you can't really feel the boost. Its worse in the lower gears. If you step on it in the higher gears, it KINDA pulls better. For the record, it's a 1G.

I'm thinking the timing is being pulled by the ECU. I guess there's no way to tell without a datalogger, and he doesnt have one. Plugs are new, wires are new. The clutch isnt slipping. And the boost DOES build, so I don't see how it could be a wastegate issue.

So, any ideas?

It still could be the wastegate, or a combination of a worn-out turbo (chipped blades) and wastegate cracks. When I replaced my 14B, it was still holding 15 lbs. of pressure, but it took forever to get there (4000-4500 rpm)! What happened with mine was the wastegate had a fair sized crack in it, so instead of turning the turbo, the exhaust gas was slowly leaking out the crack. If you're not getting all the exhaust gas pushing the turbo, it will take much longer to build boost. At 4000 rpm you're pushing out twice as much exhaust gas as 2000 rpm!

Nah he solved it. The studs on the manifold were loose

That's good to know! So it was that the exhaust was escaping, and not pushing the turbo! You think you'd hear that leak!!

Nope.
My old setup was completly cracked from the 1g mani, turbine exhaust housing to the o2 housing.
After I did my 7cm port-job system (2g mani, brand new turbine exhaust housing and o2 dump housing), I went from full boost @ 4500rpm to 3200rpm.

World of difference.