NO Boost - possible check valve failure?
 

My friend bought an FD for pretty cheap, and while it's definitely a steal for the price he paid for it, it's got a few problems. The biggest one being that the car sat outside, for over a year. So far as I can tell, the car still has its stock vacuum lines, and all of the solenoids/actuators are original.

The problem the car has is that it WILL NOT produce boost. The gauge reads maybe .1 bar. Other than that it drives fine, doesn't smoke or anything. Now, if you rapidly go on-off throttle, or if you rev the engine out and then let it decelerate a little, THEN go full throttle again, it'll give you some boost, but I couldn't catch how much. The car still felt a little slow when it boosted a little, but was markedly better than when it didn't boost at all.

Now if I remember correctly, if the primary turbo isn't giving boost, and it gives out some boost when you rapidly re-apply throttle, it means that the check valve going to the pressure chamber is leaking, right? Would that be the only thing wrong with the car?

It doesn't smoke, it does have a slightly high/slightly erratic idle, but it pulls tons of vacuum, and driving around normally (out of boost) it doesn't stutter or spit. I imagine it doesn't have any vacuum leaks, and if anything is just having turbo control system problems. Am I right or am I wrong?

No boost at all usually means a disconnected or severely torn boost coupler...
They need to be VERY carefully checked - it's easy to miss a torn one.

Dave

I wouldn't be surprised if there's a ton of leaky hoses/clamps. The engine bay looks pretty well baked.

BUT it DOES produce boost, but only very rarely and only if you do certain things, so wouldn't that signal that it isn't necessarily leaky hoses/clamps?

bump - anyone?

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