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Boost Creep

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Zerocygnal

20+ Year Contributor
641
1
Jul 1, 2002
Springfield, Ohio
I just wanted to have a few extra ideas on places to check out my problem.

Nothing other than a brake upgrade, and a hacked air can have been done in the last week. Just recently after those two mods I noticed that while in 2nd gear floored my boost sits at 8psi (Per factory gauge mind you...) and then once I hit 4200RPM the boost slowly creeps to 12psi giving me the power I originally had. 3rd Gear does the same thing except at 4500RPM every other gear seems to have normal boost ranges.

My only theory is that the wastegate probably has carbon build up all over it and is sticking slightly. I checked the Wastegate actuator, BOV, and BCS with the vacumn pump as per the manufacturers testing instructions in the shop manual. All 3 of these sub-systems are normal.

I might also add that the idle increas to 1200RPM for about a minute then resumes factory idle while stopped.

1992 Eagle Talon TSi 4G63 14b Turbo
123,235miles
All fluids flushed and topped off
Sparkplugs, wires, fuel filter, air filter, and all gaskets and vacumn hoses were replaced 1000miles ago.
All sensors tested and running within acceptable ranges.

Any ideas?
Hope I gave enough info...
 
sounds like by hacking the air can, ur just allowing more air to flow on the top end. Higher flowing intake = higher boost.
 
Let me restate....
I am supposed to get 11-12psi of boost. The problem is that it is sticking around 8psi, and then slowly creeping up to 11-12psi range.
 
Wow...that will be the FIRST time DSMtalk has ever responded more. I was really hoping for some more help on this, they seem to think it's a boost leak of some sort...
 
-To simply put, the OEM gauge display the estimate amount of boost the ECU think the motor is putting out from various sensors input. If you have a boost gauge that tap into a vacuum hose, you'll notice the delay and wrong # of psi from the OEM gauge.
-You get piss off b/c no one response to your post, if you have read the post from other members regarding the OEM boost gauge, the 1st reply they had gotten is "get a real boost gauge".
 
Well dude I care. The idle problem is normal. Infact most cars do that, sit at 1200 until at a complete stop. It has something to do with economy. What did you do to help your boost to be more consistent. I have the same problem, the whole time I thought I was just on boost probation. The ECU limiting my boost because I like to street race my buddys vtec CRX all the time. If there is a fix lemme know, I wanna smoke him by more than a car length by second gear some day:D
 
Thanks for responding. I was just fed up with the problem more than anything guys, nothing against you. It's not like it is your responsibility, you do this in your free time as I do. I appreciate it.

Yeah I know the boost gauge sucks, I only used it as a reference and I didn't for a moment believe that it was accurate. The only reason i even mentioned it is because of the fact the needle moved when the car started moving normally, simulating some kind of boost that was not originally there. I highly doubt that it is even getting 12psi. New autometer gauge is in the mail.

Laser I didn't do anything at all. DSM's have a mind of their own, it's all in how they want to represent their owners :D As you can see mine is very pissed off at me right now because it didn't get the pocketlogger for it's b-day. Heh
I can't even begin to tell you any kind of actual boost till that gauge get's here. All I can say is sometimes it is, and sometimes it isn't. I laugh at the gauge because every gear floored jumps to 1 notch below the max boost on that toy.

Thanks again.
 
Heh.. local legend has it then that if you have any boost spikes or over boost the ecu will, as I put earlier, put you on boost probation untill it feels everything is all clear. I notice the same exact thing on my car. Some times it will take off smoothly at a light, other times it will peel out when I wanna drive casually. Happend twice next to patrol cars. Thats exactly what I told em too after they pulled me over.."...dunno officer the cars got a mind of its own!!" Lucky for me the lemme go only after I pop the hood and show em what I got...lucky for me my hybrid hides well under my manifold:D
 
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