Phauss

iTrader: (3)

I decided to get elbow deep into the engine bay to try and figure out an issue I'm having with the stock twin turbos on my 93 FD. In a few words, there's a popping and stuttering sound and feeling when I give the car too much gas, so I've been looking heavily at anything actuator-controlled. It mainly happens when the secondary should start doing its thing. I was only using the primary for a time until I discovered a vacuum hose had come off. The two turbos worked beautifully after I replaced the hose. Over time, though, this problem has arisen.

While I was poking around, I found an unused blue plug (pictured) and I have no idea what it's for. It should also be mentioned that the CPU #2 doesn't work and is unplugged. I know it controls a few things, but I'm not sure what.

evo_koa

iTrader: (2)

my fd has the same plug, it doesnt go to anything

Phauss

iTrader: (3)

I was secretly hoping that was the issue, but oh well.

I've looked at the two actuators near the primary, the actuator under the exhaust manifold brick, and the actuator on the Y-pipe. It feels like something is dumping the charge from the secondary when it shouldn't be. I'm not entirely sure what else there is. I'm going to scour the vacuum houses today to see if there's anything wrong.

Also, there's some oil under the car from a known oil leak. Has anyone heard of oil pooling in an actuator?

Phauss

iTrader: (3)

Sorry for the double post, but my last reply for me thinking:

I noticed a lot of oil in my intake piping. Maybe it's finding its way into the vacuum lines. I think what I need is a catch can.

evo_koa

iTrader: (2)

oil in the intake system is normal. the charge relief valve will be open at idle so there is no issue there.

evo_koa

iTrader: (2)

i would remove the pcv valve by capping it at the intake manifold and let the oil filler neck vent to the atmosphere, that eliminated most of my oil in the intake system

Phauss

iTrader: (3)

Sounds good, I'll give that a shot and see if things clear up a bit. I might also take the actuator off of the exhaust manifold brick and see if it drains any oil. I figure it's the lowest point in the system and it would directly affect the function of the secondary, so I guess it can't hurt to check. I'll report back tomorrow with results. It's too hot to be working outside right now.

Phauss

iTrader: (3)

I was changing the spark plugs today and decided to do a few extra things under the hood. First off, I took the vacuum lines off of the turbo control actuator and I didn't see any evidence of oil in the inside.

I took the upper intake manifold off and took a quick look at the rats nest to see if there was anything obvious. Lo and behold:


That solenoid is on the bottom rack toward the front of the car. The top hose is present but the other two are missing. A quick look on fd3s.net shows me that a hose goes from the UIM to the solenoid, but the fitting is capped at the UIM. It goes from the solenoid to a check valve and then to the actuator (the necessary hoses are hooked up at the actuator.) The check valve is missing; it should be in these retainer clips:


All in all, it seems like the entire line is missing besides the solenoid and the hose from the hard line. Could I have found my problem? Or is this something completely unrelated?