Rpm drop-down and check egine light to top it off

[PaintMunky468]

Ok, I just installed an extreme psi intake. It is a wonderful part, fits well, and blow off sounds amazing!!! However i was driving around today and I notices that when in 2-5th gear at around 3+ rpm, if I drop it into neutral the rpms drop down to about 100 and imediatly bounce back. Then to top it all off, a blew a check engine light, AGAIN!

Any suggestions as to what could be causing this? could I be running lean and just not gettin enough feul into the best? Because I have an EVO III 16g turbo upgrade, 3" turbo back exaust, and this intake. Could I just be gettin too much air and not enough feul?

If so, I could go get a Walbro 190 and some 550 cc injectors to fix this problem right?

 

[DSM90AWD]

You are rerouting the BOV correct

 

[PaintMunky468]

indeed I am

 

[DSM90AWD]

indeed I am

You are definitely in need of a fuel upgrade to take full advantage of the EVO 16G, though doubt this is the cause of your idle/CEL issue.

Did you diagnose the code?

Have you checked for boost leaks and loose connections btw the turbo and BOV/MAS?

 

[PaintMunky468]

im not sure what it means to diagnose the code, because I do not have access to a diagnostic machine to get a read out as to what is wrong. And no, as lame as it is on my part, I have not had a chance to run a boost leak check for lack of time. I need to make it down to home depot to get the pvc, coupler, and fill nipple to make a check thingy. But could this be caused by boost leak?

And also, as far as a new fuel pump goes (and since we are on the topic) I noticed that a walbro 190lph fuel pump is the same price as a 255lph at dsmparts.com. Should I get a 190 or 255 according to the mods I have listed above? If I went with the 255 and 550cc injectors would it hurt my performance as apposed to going with a 190? My future goals are to get around 260-280 horse at the wheels, and sqeeze only about 18-20 psi out of the EVO gt im running. My car is a daily driver.

 

[jltcat]

it may be a vaccum leak. if you find it plz let us know

 

[alIan]

i am having the exact same problem... i'm going to perform a full boost leak test tomorrow to make sure it isnt a boost leak. here's a link to my Thread that might help.

 

[project_tsi]

You may be having leaking issues causing you to get raw, unmetered air in your system, thus causing your problem, possibly.

 

[DSM90AWD]

im not sure what it means to diagnose the code, because I do not have access to a diagnostic machine to get a read out as to what is wrong.

An ODBII code reader / scan tool or Datalogger is a MUST for working on ones own car. Many automotive shops / parts stores will even read the codes for you for free. You can then goto this TECH ARTICLE to see what the code(s) mean.

And no, as lame as it is on my part, I have not had a chance to run a boost leak check for lack of time. I need to make it down to home depot to get the pvc, coupler, and fill nipple to make a check thingy. But could this be caused by boost leak?

Most definitely. But I'd first check the obvious (CEL) as you know for sure something is not right.

And also, as far as a new fuel pump goes (and since we are on the topic) I noticed that a walbro 190lph fuel pump is the same price as a 255lph at dsmparts.com. Should I get a 190 or 255 according to the mods I have listed above? If I went with the 255 and 550cc injectors would it hurt my performance as apposed to going with a 190? My future goals are to get around 260-280 horse at the wheels, and sqeeze only about 18-20 psi out of the EVO gt im running. My car is a daily driver.

I woudl definitely recommend the 190LPH "rewired" as would support ~400HP which is about the limits of the 550cc injectors. The 255HP supports ~550HP but would require an aftermarket AFPR as would overrun your stocker

 

[PaintMunky468]

Hey thanks for the help guys, i really appreciate it! i will be doing a boost leak check today or tomarrow. But until i contact my local dsm shop and find an answer to this rpm drop-down problem, i chose not to drive my car.

P.S.- would having a boost leak damage the turbo or engine, or just really hurt my performance?

 

[DSM90AWD]

P.S.- would having a boost leak damage the turbo or engine, or just really hurt my performance?

By leaking boost, your turbo is going to have to work harder (i.e. spin faster, more heat) to produce the same boost pressure at the intake manifold.

As an example say your SMIC has 2psi pressure loss and you have a 4psi leak at the BOV. To generate 14psi at the manifold your T-25 would have to produce 20psi at the compressor outlet. Read a compressor flow map of a T-25 and you'll see why 20psi is not good.

So to answer your questions, yes