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newbie with idle problem

Quote:
You can always put the old sh*t on and go from there then.




What's the point in that?
 

MMCVR4

Well-known member
Joined
Feb 16, 2005
Messages
740
Location
SoCal
Quoting galant1517:
Is there anywhere to get the ISC other than the dealer? They want $332 + tax.


I googled it and found this - click
 

AnotherNewb

Well-known member
Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
Quoting galant1517:
Quote:
You can always put the old sh*t on and go from there then.




What's the point in that?



Eliminate what has changed. If he can go back to his old ECU and his idle problem clears up /ubbthreads/images/graemlins/dunno.gif
 

Thank you for that link MMCVR4, as for putting the old stuff back in, that doesn't help me figure out what's wrong with my car. It only tells me that my old ecu is too slow or too obsolete or whatever to recognize this issue I'm having. DBossman said it best when he said that jeff (keydiver) wouldn't have the reputation that he does by "f***ing peoples sh*t up". It seems to me that I'm just missing some piece of the puzzle here. .
 

stevep

Well-known member
Joined
Oct 23, 2004
Messages
416
Location
St. Charles, IL USA
Quoting galant1517:
I've got the BISS cranked shut, I've looked fifteen times for air leaks, can a pcv valve be the culprit? The reason I ask is that the other vent on the V/C is to atmosphere.

Is there anywhere to get the ISC other than the dealer? They want $332 + tax. I am really confused about this whole situation because the car idled perfectly on my old ecu and 450's.



Yes, The PCV valve is a path that bypasses the throttle plate. The rocker cover breather needs to be plumbed into the intake or it's a unmetered vacuum leak.

Rock auto sells the new style ISC for about $80.
 

I know there is a site around that rebuilds ISC i remember buying one a couple years back, but really any rebuilt one with a good warranty should do the job i would check out that rock auto one mentioned above.
 

First of all, thank you to everyone who has contributed or even simply read this post. This is easily the most trying issue I've encountered in all my mitsu experience. As it were, I've put the thing back as close to stock as possible, and I've still got the hunting idle. So I'll be removing the intake manifold as soon as spare time allows. I'll be doing an abs delete and cruise control delete at the same tinme so I'll let everyone know how that goes. I can't believe that as soon as I decide to chip my car and put bigger injectors in that something ese decides the crap the bed.
 

AnotherNewb

Well-known member
Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
Quoting 1qkfwd:
The only thing I can suggest is boost leak test the car, then go through all the basics. Did you install the bigger injectors with the chip? Maybe there's a leak somewhere. Injector o-ring maybe.



Still sounds like you need to do a boost leak test. Hoses and couplers split all the time.
 

I build 20 lbs no problem, and the off idle performance hasn't changed much, if at all. But I'll check anyway.
 

AnotherNewb

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Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
Yes, with a boost leak you can still build your target boost, but your turbo will be working harder to do it. However... with a MAS attached to the inlet of the of the turbo, any air the enters post MAS will not be metered.

What I am suggesting is that you have an air leak (i.e. vacuum leak) and unmetered air is entering you engine post MAS causing it to run lean then try to balance your idle out. If you do a boostleak test, you will possibly find a way for air to enter your engine after the MAS. /ubbthreads/images/graemlins/idea.gif
 

I get that. I guess its just weird to me because I used a coupler with a working psi rating of 45 psi and a burst pressure of over 60 psi, all with T-bolt clamps. And I can't see a vacuum line or intake gasket etc would cause a 3100 rpm idle with the throttle open/closed switch unplugged. But failures happen all the time and I usually end up finding the failure point of everything I run on this car. I mean, I snapped a rear axle when my car was bone stock, I've got 43k on it since I've bought it, and I've had 7 trannies in it, 4 clutches, 3 turbos, 2 driveshafts, I'm on my third set of tires, second head gasket, and third water pump. And I'm sure a bunch of other stuff I can't remember. I'm just frustrated.
 

AnotherNewb

Well-known member
Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
/ubbthreads/images/graemlins/uhh.gif .....and a partridge in a pear tree... /ubbthreads/images/graemlins/grin.gif
 

adamvr4

Well-known member
Joined
Sep 18, 2005
Messages
184
Location
skokie/ il
i dont know if this has anything to do with the idle problem but did u install the clutchwire with the chip? Also i had sort of the same problem, but i had an exhaust leak that was causing my oxygen sensor to go bad and causing my idle issues. just throwing it out there!!!
 

14bCrazy

Well-known member
Joined
Mar 25, 2003
Messages
5,707
Location
Virginia
Quoting galant1517:
I get that. I guess its just weird to me because I used a coupler with a working psi rating of 45 psi and a burst pressure of over 60 psi, all with T-bolt clamps. And I can't see a vacuum line or intake gasket etc would cause a 3100 rpm idle with the throttle open/closed switch unplugged. But failures happen all the time and I usually end up finding the failure point of everything I run on this car. I mean, I snapped a rear axle when my car was bone stock, I've got 43k on it since I've bought it, and I've had 7 trannies in it, 4 clutches, 3 turbos, 2 driveshafts, I'm on my third set of tires, second head gasket, and third water pump. And I'm sure a bunch of other stuff I can't remember. I'm just frustrated.



Just do the test. I have had times when I swore that put everything together right only to test it and find that I had a leak. /ubbthreads/images/graemlins/dunno.gif
 

Alright, I've just finished the NT throttle body, ISC/FIAV block off plate, and cruise control delete. It seems to have done the job. No more idle surge, I don't have to deal with the stupid TB elbow anymore, and I got rid of the cruise control that I never used anyway. I still have to reset the ignition timing and the tps, but it runs pretty good. I used a hyundai throttle body, which is worth mentioning because it doesn't use a throttle opem/closed switch. I am not sure as of yet how this will affect me, but I did notice that my low fuel trims jumped from 100% to 138% percent. Also it takes about 3 seconds after closing the throttle for the injector duty cycle and the injector pulse width to drop to zero. The tps reads 12.1% at closed throttle, so maybe these values will change once I've reset the tps to 10%. I have also considered just grounding the throttle open/closed wire, but maybe some of you may be able to reinforce the feeling I have that this probably isn't a good idea. It seems to me that if the ecu always thinks the throttle is closed, regardless of where the tps actually is, that the car won't run right. Thanks y'all.
 

AnotherNewb

Well-known member
Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
Yep. You need the throttle closed switch, other wise be prepaired for stalling. And don't just ground it, that will only make life worse.
 
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