Notices
Evo General Discuss any generalized technical Evo related topics that may not fit into the other forums. Please do not post tech and rumor threads here.
Sponsored by: RavSpec - JDM Wheels Central

Car breaks up under boost even under no load (Video with DETAILED description)

Thread Tools
 
Search this Thread
 
Old Dec 20, 2014 | 06:27 PM
  #16  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by eXtreme-Speed
I know you checked the spark plugs, did you try re-gaping them?
Yea I went down to 0.22".
Tuner has been through at least 2 sets of plugs so far.

Its deff a fuel related issue

Last edited by evolvedevo91; Dec 20, 2014 at 06:53 PM.
Reply
Old Dec 20, 2014 | 08:37 PM
  #17  
thatguy5's Avatar
Evolving Member
iTrader: (1)
 
Joined: Aug 2011
Posts: 163
Likes: 0
From: Norcal
if injector duty is at 100% you def have spark blowout due to the large amounts of fuel you are dumping in, this would also explain the fouled plugs. im running 1200s and my injector duty is around 70%. 2150s are typically used for 800whp e85 setups which require 30% more fuel than pump.
Reply
Old Dec 20, 2014 | 10:30 PM
  #18  
robbyredneck's Avatar
Evolving Member
iTrader: (3)
 
Joined: Nov 2013
Posts: 293
Likes: 0
From: upstate ny
Originally Posted by evolvedevo91
I have a double pumper.
Only one pump was powered at first.

My tuner powered the 2nd pump today and he said even at 136% injector duty cycle the car was going lean (14.0) into boost. Fuel pressure was around 60 psi into boost with both pumps running.

Would everyone agree the injectors can be the only probable cause at this point?
Brand new fic 2150s I can't believe this would be the issue but looks like it.

I even told him to remove the filter element just today in hopes that it was causing a resitrction. He told me it was clean, and it idled a little better without the element.
can you watch fuel pressure related to boost? i tuned an sti that had a phantom lean condition that turned out to be the pressure relief valve in the pump itself leaking fuel intank. it showed high dc and went lean at boost but idled and under 50 psi fuel pressure was fine. i ended up powering the whole sending unit up outside of the tank and found it.
Reply
Old Dec 21, 2014 | 12:39 AM
  #19  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by thatguy5
if injector duty is at 100% you def have spark blowout due to the large amounts of fuel you are dumping in, this would also explain the fouled plugs. im running 1200s and my injector duty is around 70%. 2150s are typically used for 800whp e85 setups which require 30% more fuel than pump.
So its safe to say my tuner probably doesn't want to use the 2150s? I'm not so sure anymore that he has that much experience with a large injector on pump fuel.
I think you're right because I was getting a P170 for a while before the tune.

Originally Posted by robbyredneck
can you watch fuel pressure related to boost? i tuned an sti that had a phantom lean condition that turned out to be the pressure relief valve in the pump itself leaking fuel intank. it showed high dc and went lean at boost but idled and under 50 psi fuel pressure was fine. i ended up powering the whole sending unit up outside of the tank and found it.
Well I'm thinking 60 psi should be okay for the stock 8 turbo?
Each pump works individually I know that for sure. I have an aem gauge in cab so that's what the tuner has been referencing

Last edited by evolvedevo91; Dec 21, 2014 at 02:29 AM. Reason: correct obd code number
Reply
Old Dec 21, 2014 | 02:57 AM
  #20  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Does anybody else think e85 would be a better fuel for these injectors?

I'm about ready to drain my 93 and get the e85 in there. Tuner seems to favor e85 as well.
Reply
Old Dec 21, 2014 | 12:01 PM
  #21  
Fast_Freddie's Avatar
Evolved Member
Veteran: Navy
iTrader: (50)
 
Joined: Jun 2007
Posts: 2,706
Likes: 15
From: Lexington Park, MD
There is something mechanicall wrong with the car... If it is at 136% IDC on pump, putting E85 on it is only going to make the IDC worse if there is an issue...
Reply
Old Dec 21, 2014 | 12:11 PM
  #22  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by Fast_Freddie
There is something mechanicall wrong with the car... If it is at 136% IDC on pump, putting E85 on it is only going to make the IDC worse if there is an issue...
Any idea where to start?
I have no idea. I've been over this car top to bottom multiple times now. Can't seem to pinpoint an issue.
Reply
Old Dec 21, 2014 | 03:38 PM
  #23  
robbyredneck's Avatar
Evolving Member
iTrader: (3)
 
Joined: Nov 2013
Posts: 293
Likes: 0
From: upstate ny
are the pumps on a hobbs switch?
Reply
Old Dec 21, 2014 | 03:46 PM
  #24  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by robbyredneck
are the pumps on a hobbs switch?
#1 pump is wired using the stock relay and wiring. Used this to tune until the issue then we connected #2 pump.

Pump #2 is on a Hobbs switch that triggers at 2psi.
Reply
Old Dec 22, 2014 | 11:51 AM
  #25  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
I hear my fuel pump relay clicking extremely loud when I'm on and off the gas pedal.
Would this point to a failing relay?
Reply
Old Dec 22, 2014 | 01:45 PM
  #26  
Ev0ikon's Avatar
Evolved Member
iTrader: (18)
 
Joined: Jan 2004
Posts: 3,677
Likes: 11
From: 3rd Rock {from = sun}
My guess is that you are still having the Inj resistor pack plugged in. They need to be removed using those high-Z injectors.
Reply
Old Dec 22, 2014 | 02:18 PM
  #27  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by Ev0ikon
My guess is that you are still having the Inj resistor pack plugged in. They need to be removed using those high-Z injectors.
Nope I have the resistor delete plug. And I even just checked it and its connected well.
Reply
Old Dec 22, 2014 | 06:06 PM
  #28  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Well I discovered there is oil covering the cam sensor.
Could this be my issue?
Reply
Old Dec 22, 2014 | 06:37 PM
  #29  
robbyredneck's Avatar
Evolving Member
iTrader: (3)
 
Joined: Nov 2013
Posts: 293
Likes: 0
From: upstate ny
Originally Posted by evolvedevo91
I hear my fuel pump relay clicking extremely loud when I'm on and off the gas pedal.
Would this point to a failing relay?
could be . i had a lq4 t76 turbo regal that had a relay **** the bed and behaved very poorly. it degraded though and would present in fuel pressure nosing over. can you go back to one pump but keep both circuits and test them individually?
Reply
Old Dec 22, 2014 | 06:45 PM
  #30  
evolvedevo91's Avatar
Thread Starter
Newbie
iTrader: (3)
 
Joined: Aug 2014
Posts: 94
Likes: 0
From: .
Originally Posted by robbyredneck
could be . i had a lq4 t76 turbo regal that had a relay **** the bed and behaved very poorly. it degraded though and would present in fuel pressure nosing over. can you go back to one pump but keep both circuits and test them individually?
Both circuits work I can tell because the #1 (main relay pump) shows about 35-40 psi at idle.
#2 pump doesn't power on until I'm in boost (so it hasn't powered on yet)

I mentioned it to my tuner and he didn't act like that was an issue.
I'm pretty sure the click is normal I mean it is a relay that turns on and off. Not sure why it's so loud now.

And tuner also told me a little bit of oil is normal in the CAS housing.
So now I'm back to square one. And have no idea what's wrong.

Last edited by evolvedevo91; Dec 22, 2014 at 06:48 PM.
Reply



All times are GMT -7. The time now is 03:35 PM.