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1G How to tell if my turbo is bad?

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10+ Year Contributor
Jan 15, 2011
Greeley, Colorado
Hello everyone,

I apologize if this has been asked before but what are the tell tale signs that my turbo would be bad. I'm trying to figure out what is going on with my car because I just installed a boost gauge and my car is completely stock but my glowshift boost gauge is only reading 4 to 6 psi even at 4 or 5k RPMs in 2nd, 3rd, 4th, and 5th gear.

I thought that maybe it was because I had ECMLink V3 tuned badly however I replaced the EPROM ECU with a stock one and I'm still getting the low boost. From what I have seen stock boost should be about 11psi. Could my boost gauge just be completely off? It's a glowshift 3 in 1 that reads up to 60 psi of boost. I know it's a bit excessive cause I'm not going to push 60 psi even after I have completely built my engine. Also I'm not sure if this could be an issue but my car does not idle properly. However it runs fine at all times when not idling. It idles bad with the EPROM ECU and with the stock ECU. I even tried simulating the idle switch with the throttle in the ECMLink software and that made no change.

I was thinking possibly a vacuum leak but I'm not sure. I would of also thought it was a boost leak however the car drove fine when I first got it a couple months ago and I have not made any changes to the intake at all. My guess is that I must of bumped a vacuum line somewhere and all. I plan on removing all the emissions control stuff this week when I receive my EGR block off plate and at the same time I'm replacing the vacuum lines with some good ones I ordered off of

Is there anything else you guys think I should do to figure out what my problem is?

Thank you for all of the help I really appreciate it.
The fact that you have a rough idle, leads me to think that it is a boost leak. As for a boost leak will cause such a thing. It would also explain why you are only building 6psi of boost. I would say do a proper boost leak test, and fix all of your leaks. Chances are there are a couple. Also, it is a good idea to get your spark plugs and wires replaced, can't hurt. Here is a video and a link on proper boost leak testing.

YouTube - Boost Leak Testing 201: Using the tool.
Thanks for the vid and all. I actually replaced my plugs with good NGK's and also replaced my wires with NGK wires as well. Ill try a boost leak test and see if I have any leaks and fix them on monday and see where that gets me.
If you question your boost pressure then you need to do a proper boost leak test to above what you are going to be running pressure wise and use a spray bottle of soap and water. Really any time you mess with IC pipes or anything else that sees pressure you want to do a boost leak test to be sure it's sealed up.

If you are going to talk about a log, then post the log in question so we can view it instead of trying to figure out what you are describing.

Paragraph your posts. I didn't bother reading all of it because of that and I'm sure others will skip over it as well as it's a pain trying to read it.
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