when car is boosting runs like crap

[chehsgsx]

i know not another 'car runs like crap" topic but i couldn't find anything just on my problem. when u drive normally with my car every things good but if ## in low rpms and floor it the car stumbles till boost is at max (12 pounds) but after the boosting up proses is done car runs great again... just kinda like it bogs down when its building boost. any suggestions i was thinking maybe the sensor for boost presser is bad but idk. any help would be great.

the car is in the getting it back to good running order plane rite now just replacing all the parts that need to be replaced with stock or better parts,i haven't done much work other then this ### i dont want to #### the motor up.


on a side note anyone got 4 stock shocks they want to give me? its a shot in the dark i know.

 

[snowborder714]

Have you done a boost leak test lately?

 

[PitBull]

I am facing a similar problem. My gst seems to run fine until I start building boost(10+), then it will get boggy. I'm guessing it's a boost leak, but I'm a newbie...

 

[snowborder714]

Perform a boost leak test. Here's how to make the tester - http://www.vfaq.com/mods/ICtester.html

Here's how to perform the test (as posted by oldman):

Originally Posted by BLT procedures
1. Disable your mbc.

2. Turn your motor to 30* ATDC to avoid valve overlap.

3. Start your test at the TB elbow and focus on area behind the TB first.

4. Spray soapy water at TB gasket, BISS, TB shaft on both sides, IM gasket, injector insulators, brake booster, afpr and all vacuum lines/connections.

5. Open your oil cap and listen for leaks. (PCV, valve seals/guide, rings)

5. Listen to your tailpipe for leaks. (EGR, valve overlap, jumped timing, bent/unseated valves)

6. Once all leaks are fixed, move the tester back to the turbo inlet.

7. Spray down the compressor cover (known leak), BOV return/flange (DO NOT TAP YOUR BOV LINE FOR YOUR MBC!!!), IC end tank/fins and all connections. Re- test.

8. Note that you will leak air into the crankcase through the turbo seal but do not panic, this is normal during a static pressure test as long as there are no shaft play.

The desired test result from the begining of the LICP (bypassing turbo) is around 20psi (on boost gauge) with the compressor set at 30psi, while taking no less than 30 seconds to bleed down to 0.

As a reference, my last test on my 500 mile new engine, I was able to pressurize the system to 25psi, bled down to about 16psi (my 1G bov) in about 30seconds, then took about 3 mins to 6psi and just kinda lingered there for a while. It's not easy to do but the point is it's possible. My next goal is 30psi After motor break in and Dodge modding my BOV. A boost leak test is one of most pita but important regular maintenace task, the key is patience and endurance, have fun.

Just so a simple search for boost leak test and you'll get a bunch of threads with good info on this.

 

[meliketoball]

I love that homemade boost leak tester! Try that out buddy!

 

[phreak965]

i had a similiar problem a couple years ago, i had horrible idling also...hella problems...turns out that my lower IC piping wasn't clamped on good since i had just messed with it. so if you can't get your boost leak test to even hold pressure, follow the lines where air would go and you might find your culprit! gl

 

[chehsgsx]

ok i have the parts to do the leak down test and ill post back the results latter on.
maybe while im down there i can figure out where my exhaust leaks from and jb weld it to

 

[snowborder714]

If you'd like to try and find an exhaust leak, I suggest using Seafoam.

And I'm assuming you meant boost leak test, not leak down test (which is much different)

 

[chehsgsx]

ok did the test and i have two holes in the intercoller where a bracket pooped out ( y the hell u would ever pop rivet something thats gona see lots of stress and pressure is beyond me) besides that the intercoller was all messed up wit big scratches and it was all bent up..just not good sooo i picked up my top mount intercoller from my mekur and used it as a side mount the bi*** works though and the merkur intercoller flows a thousands times better soo yeah thanks for all the help guys i may post some pics her latter

 

[99gst_racer]

chehsgsx - Please use proper grammar in your tech posts. Between your lack of puncuation, lack of capitalization, and mispellings, your posts are a mess to read.

 

[chehsgsx]

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theres the pics and sry for the spelling errors aim speech

 

[99gst_racer]

theres the pics and sry for the spelling errors aim speech

Do you honestly think it's going to help your cause by apologizing for your poor grammar by using poor grammar?

Not to be a dick, but this is your final warning.