turbo problem

[samster]

I have an all stock 91 Legacy Turbo with about 140K miles. The engine is cutting off under heavy boost. Right before the engine cuts off, I can hear clicking noises. The cut off only occurs for an instant and then power returns. Just took it to the shop today and the mechanic says the solenoid tested ok and the diaphragm is holding vacuum, so the problem is probably with the wastegate inside the turbo. The mechanic says the only fix is to replace the turbo or just live with the problem. Is this a correct diagnosis?

Thanks for any help

[vrg3]

Your mechanic is probably wrong. Wastegates don't usually go bad in a way that can cause this.

Hook up a boost gauge and measure what the maximum boost you get (before this cutting off) is. If your engine is overboosting you may be hitting an overboost fuel cut.

High boost is also when it's hardest to make a spark. When was the last tuneup? Did you check the condition of the spark plugs and wires?

High boost also requires the most fuel. You should check fuel pressure at boost. It's possible that your fuel filter is clogged or your pump is dying.

Your problem really sounds most like an ignition issue.

[LegacyT]

Yup, like vrg3 said, hook up a boost guage first. If your hitting 13 psi then your definately experiencing fuel cut. And The most common reason for these cars to do that is because of seized wastegates. My car had this problem when i got it. The wastegate was a little corroded. I sprayed penetrating fluid at/into the wastegate and wiggled it until it opened and closed smoothly. that fixed it. BTW This advice came from my dad, whos been a Subaru mechanic for 20 years. Give it a try before spending any money.

Mark,

[Redline Dreamz]

i would say fuel cut as well but the clicking sounds almost like detonation when fuel cut is kicking in... sounds like a multiple problem.

[michael888us]

i got the same problems too , just replace youe spark plug wire maybe the plugs too,your problem should went away immediately,