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87 951 VEMS Install

Old 05-08-2017, 06:10 PM
  #46  
gruhsy
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Have you checked your IAC for vac leaks. Just curious.
I posted a thread on here about doing the seal on it.

I just got my new seal in the mail.

Huge difference with the new seal 3mmx33mm

Leaks with old one and no leak with new seal.

Originally Posted by running_cold924 View Post
Ok cool. Talked with Peep, gotta reverse the polarity in VEMs for the IAC valve, should fix the idle surge.
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Old 05-08-2017, 06:17 PM
  #47  
running_cold924
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what seal did you replace? All the hoses are a few years old, even the mounts are new(er)

This is the seal for the body of the valve?
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Old 05-08-2017, 06:59 PM
  #48  
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The internal seal. If you plug one end and blow on the other end it will give you an indication of how good the seal is.

Massive difference with the new seal in on mine compared to the old one.

My idle on my car was bouncing all over the place with the M-tune due to I am sure my IAC. My engine is out of the car at the moment but I am sure it will run much better when I get it back together.

https://rennlist.com/forums/944-turb...tabilizer.html


Originally Posted by running_cold924 View Post
what seal did you replace? All the hoses are a few years old, even the mounts are new(er)

This is the seal for the body of the valve?
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Old 05-08-2017, 07:45 PM
  #49  
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ok, thanks for the heads up!
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Old 05-10-2017, 02:47 AM
  #50  
NCLA951
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I don't have AC and I got tired of leaking IACs so I'm running without one now. As long as I give it a little throttle on first start of the day for a minute or so it does fine. Stupid leaky IACs.
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Old 05-10-2017, 10:00 AM
  #51  
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It is very easy to fix them. I was tired of the same sort of issues. Then I decided [email protected]#$ it and took it apart. Wished I would have done that ages ago. If one has any simple mechanical skills it can easily be done.

Originally Posted by NCLA951 View Post
I don't have AC and I got tired of leaking IACs so I'm running without one now. As long as I give it a little throttle on first start of the day for a minute or so it does fine. Stupid leaky IACs.
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Old 05-10-2017, 02:51 PM
  #52  
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Yeah I fixed one, new o ring and epoxied it shut, then it blew open after, and I grew tired of removing my manifold to mess with it so I just left it out. If I lived in a colder place I might worry about it more.
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Old 05-10-2017, 02:53 PM
  #53  
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If I ever decide to implement some anti lag I'll need it back though. But that will probably be right before I plan on replacing the turbo, crossover and header.
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Old 05-14-2017, 01:04 PM
  #54  
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Default Injector size

Sam, you are using the 80 lb injectors as well so then under engine setup it should be an 841cc injector size right? Mine days 380cc. That may be part of my problem with the idle because changing polarity of my iac didn't fix the problem.
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Old 05-14-2017, 01:18 PM
  #55  
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markl951 posted this pic for the wiring for reference.


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Old 05-14-2017, 01:49 PM
  #56  
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Originally Posted by running_cold924 View Post
Sam, you are using the 80 lb injectors as well so then under engine setup it should be an 841cc injector size right? Mine days 380cc. That may be part of my problem with the idle because changing polarity of my iac didn't fix the problem.
in VEMS the "injector size" box is just for your own reference - changing it doesn't actually change anything about the tune.

you need to tweak the "reqfuel" depending on injector size.
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Old 05-14-2017, 04:10 PM
  #57  
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Default Thanks rocket.

Clears things up some. Looks like I'm sitting right @ 5.0ms, sounds about right with e10(93). I just can't wrap my head around why my idle is ****. I have logs if anyone would like to see them. Totally stumped...
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Old 05-14-2017, 04:24 PM
  #58  
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small changes make a big difference, and you need to adjust the VE table as well.
fwiw my setting for NA injectors is 12ms.
turbo injectors are 50-60% larger than NA so you might need to bump up to 7 or 8ms.

dont bother thinking about fuel ethanol content with reqfuel - get it running smooth and let the VE auto tune figure that out.
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Old 05-14-2017, 04:56 PM
  #59  
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Really, that much? I did the calculation to get the number and it's actually 4.8. you​ running 12 on an n/a is very interesting. I will try bumping mine up and see what happens.
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Old 05-14-2017, 05:06 PM
  #60  
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Req fuel is good to have set correctly but ultimately your VE table and enrichment curves are what determines your fueling. They're all scaling your req fuel, so either way it'll be ok.

On my NA, best idle is around 13-14:1 AFR and it likes about 15-20* of ignition advance. Can you check with a timing light to see if you're actually getting your base timing? All you need is a basic one, the rest is setting up fixed timing temporarily in the tuning software.
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