Turbo problem

[blkmiller]

I have a 1991 eagle talon tsi. I just did a timing and water pump job on the car. The car starts and runs but its rough. I then noticed that my turbo isnt spooling. Before I did the work on it it was working fine. What would cause the turbo not to work? The wastegate actuator?

 

[SrKegler]

If the car was running fine before the timing belt change, chances are you didn't get the mechanical timing set correctly. Probably a tooth or two off at the cams. Timing belt change doesn't affect the turbo system.

Will let an expert jump in on the turbo problem. Mine has always worked for the past 22 years.

 

[blkmiller]

The car idles fine now. Just no boost?

 

[GRAVEDIGGER]

It could be the wastegate actuator not holding the wastegate all the way closed as that would cause you to not be able to build boost, but if you never touched it I don't know how it would go from working to not working just by changing the timing belt and water pump.

 

[blkmiller]

It had been sitting for a really long time.The actuator is very rusty...

 

[GRAVEDIGGER]

It sounds like you need to pull the actuator arm off of the wastegate flapper and see if you can move the flapper door open and closed freely. It should move freely with no binding or anything like that.

 

[blkmiller]

I took the actuator arm off and the flapper moves with ease. actuator not so much...

 

[edged1g]

I took the actuator arm off and the flapper moves with ease. actuator not so much...

The actuator has a stiff spring and diaphragm inside. It doesn't move easily. Put compressed air to the inlet and make sure it opens. A stuck or frozen actuator would over boost, not prevent boost from building.

 

[blkmiller]

What would prevent boost from building?

 

[TalonSpeed]

You are not answering the major problem. Does the car idle the same as it did before the t belt install. If not u didn't install it correctly. Jumped timing will make the engine extremely laggy.

If the engine is running fine and no boost is built, the turbo is shot, wastegate stuck open, or major boost leak.

 

[autocrossn]

I had this same problem turns out it was my boost controller

 

[blkmiller]

That's what I was thinking... Would that keep it from building boost?

 

[autocrossn]

do you have a boost gauge? it should still hit stock pressure
How did you hook up the vac lines​

 

[blkmiller]

I didnt hook any of it up. The previous owner did. Looks like a cheap boost controller..

 

[autocrossn]

Sounds like thats your problem.. make sure you have them hooked up properly
And an actual boost controller

 

[honda_burner]

Disconnect the boost controller and hook the actuator vacuum line straight to the turbo to test and see if its the boost controller. It should hit stock boost (~10 psi) if that is your problem.

 

[blkmiller]

I'll have to go out to the car later tonight or tomorrow after work and post a pic of what it looks like.. Im lost...

 

[blkmiller]

Well I finally got a chance to test my wastegate actuator.. It tested good. My turbo spins freely and its not loose.. Could a bad BOV prevent boost from building?

 

[A Sharp]

Does the car idle smoothly and run like an non-turbod vehicle (smooth consistent power response across all RPMs)? If so, we can probably eliminate a bad timing belt job. As Talon Speed mentioned before, having the timing belt off by a few teeth will make the car run like garbage and make it difficult for the turbo to spool properly. Also, if the engine runs smoothly with consistent power delivery you can also eliminate having a large boost leak. If there was a boost leak large enough to let all the boost escape, the engine would run extremely rich and dog out like crazy.

If you open you windows and while you accelerate can you hear any spooling noises?

If the turbo simply isn't spooling up at all, it must mean that exhaust gasses aren't flowing around the exhaust turbine or that the turbine shaft is sheared off in the middle. If the turbine shaft was sheared off, you would hear lots of ugly noises coming from the turbo and probably be burning huge amounts of oil (blue smoke from exhaust). Most likely, though, is that your wastegate is damaged or that it is sticking open for some reason.

Lastly, a bad boost controller couldn't prevent your turbo from spooling. It could only cause over-spooling.

 

[Tiki2777]

Make sure you don't have any vacuum/boost leaks, this is a very common issue on dsms and even small vac line leaks can cause noticeable power loss and spool increase. Also the BOV leaking could contribute to this problem.

 

[blkmiller]

Does the car idle smoothly and run like an non-turbod vehicle (smooth consistent power response across all RPMs)? If so, we can probably eliminate a bad timing belt job. As Talon Speed mentioned before, having the timing belt off by a few teeth will make the car run like garbage and make it difficult for the turbo to spool properly. Also, if the engine runs smoothly with consistent power delivery you can also eliminate having a large boost leak. If there was a boost leak large enough to let all the boost escape, the engine would run extremely rich and dog out like crazy.

If you open you windows and while you accelerate can you hear any spooling noises?

If the turbo simply isn't spooling up at all, it must mean that exhaust gasses aren't flowing around the exhaust turbine or that the turbine shaft is sheared off in the middle. If the turbine shaft was sheared off, you would hear lots of ugly noises coming from the turbo and probably be burning huge amounts of oil (blue smoke from exhaust). Most likely, though, is that your wastegate is damaged or that it is sticking open for some reason.

Lastly, a bad boost controller couldn't prevent your turbo from spooling. It could only cause over-spooling.

The car idles fine. I dont hear any spooling of the turbo. I deleted the boost controller for the time being to make sure that wasnt the problem. I dont have any blue smoke coming from the exhaust, but there appears to be a leak on the back side of my intake manifold? Could that cause a problem with the boost? Also could the BOV have something to do with it? Also I dont hear any bad noises coming from the turbo...

 

[A Sharp]

Yes, a vacuum/boost leak at the IM could definitely cause issues. If there are nipples with no lines attached (perhaps because of an EGR system delete) make sure that they are capped. Inspect all the lines connecting to the exhaust manifold for cracks or damage. With the engine running, try pinching them off one by one. If the engine significantly changes speed after pinching one of the lines, chances are that the line is leaking.

If you are referring to a vacuum leak where the IM mates with the head you could try spraying a bit of carb cleaner in there to see if it changes your idle as well (the gasses from the carb cleaner would cause irregular combustion if they entered through a vacuum leak).

The BOV could cause issues. I'll assume that you're using the stock recirculated setup. You could pull the BOV off and inspect it for damage. Turn it upside down and press your thumbs down on the valve. You should be able to compress it, but with a lot of resistance. If it compresses easily, then the spring/diaphragm inside are shot. Also, you shouldn't be able to blow into the nipple on the top. If you can, the diaphragm is torn and is creating a boost leak among other problems.

 

[lasershark]

You are talking about not building boost while driving right? Not sitting in your driveway idling/parked?

 

[GRAVEDIGGER]

You are talking about not building boost while driving right? Not sitting in your driveway idling/parked?

Good question! Could that be the "problem"???

If not, maybe it's time for a boost leak test.

 

[blkmiller]

I took the car to a shop, the timing is good. But the car now idles at 3g? And has a lack of power. I can't accelerate to keep up with traffic. And a friend said I have black smoke coming out of the exhaust!?!?! The turbo isn't making the normal boosting noise? It hard to explain but sounds whinny?