Hi guys, I got a problem with my Evo 7 GSR.

After I installed the Boost Gauge and replaced the plastic intake pipe with a hard-pipe, I noticed below problem :

-Eveytime I drive without the A/C on, car is really sluggish, turbo cannot spool up fast and cannot boost over 10PSI. Car is not responsive at all.

-If I turn ON the A/C , car drive really fast like normal, Turbo spool up super quick and boost to 20PSI easily.

I have checked all the vacuum line and tubing and there are no leak at all. I do not have manual boost controller as well.

Do you have any ideas why it could happen this way ? Problem has been existed for 3 weeks and it is driving me crazy (it is my DD).

Thank you for your inputs !

 

retrace your install and look for problems. No idea what could cause this, maybe you tapped into something you shouldn't have for the boost gauge. Try and pull OBD codes and see if anything is there.

 

Hi Biggiesacks,

I connect the gauge to the Interior Light Fuse under Dash. The gauge is working as normal as well.

Also, I do not have Tactrix cable to check for the OBD code.

Thank you

 

You dont need a tactrix, any obd reader will do.

 

My check engine light is not On. Everything else is normal. Do I need to check the OBD code?

Thank you

 

Where is your boost source for the gauge?

 

everything else is normal except your car isnt working right..... If it worked fine before your "install" then that probably isnt a coincidence. Also have you done a boost leak test? Yes try and pull codes regardless if light is on or not. Its troubleshooting, you don't assume anything.

 

Hi ||Demon||,

I have "Tee" the boost gauge into the vacuum line between intake manifold and BOV.

At the first time when I started the engine, the boost gauge needle was shaking/ vibrating between -15 and -20 all the time at idle. It has been like that for a few days and suddenly back to normal at -20 at idle (not moving/shaking anymore).

Do I have a faulty boost gauge that is causing the problem ? Any electric circuit shock ?

Thank you

 

Hi Biggiesacks,

I have not done a boost leak test. All the vacuum lines seem to be normal.
I will try to find a OBD reader to see if there is any codes at all. Do you have any other things that I can check at this stage ?

 

I really gotta stress doing a boost leak test. As an evo owner its just one of those things you gotta get use to doing. You could have gotten a bad tank of gas that is causing you to fall back onto low octane maps. Its really hard to diagnose these kinda of things, especially strange ones like yours, over the internet. Thats why i advised starting from the ground with the OBD reader and a boost leak test. Also since your problems apparently started after this install, going over every aspect of it with a fine tooth comb. If you pulled into my garage those are the first things i would do.

 

Thank you for your input. I will do a boost leak test this weekend.

Also, if there is not boost leak, do you think I can fix this problem (low octane map) with a tune up ? I normally run Octane Unleaded 98 but sometimes I still run Unleaded 95 (cannot find the gas station with 98).

Another thing is, when my car run normal, gear shift is really smooth, clutch feels really responsive. If my car does not run normal, gear shift is stiff and car can stall easily.

Thank you

 

I think you are talking about RON not octane rating correct?