The Top Mitsubishi Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

What would cause this to ecu

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Should I be worried if I replace the ecu that it's gonna happen right away?





 

belize1334

Well-known member
Joined
Nov 18, 2003
Messages
3,316
Location
Bozeman, MT
Someone will likely correct me but I believe those are the ISC drivers. A faulty ISC will fry them and it'll do it again to the next one. Replace the ISC motor (or block it off) before you replace the ECU.
 

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Also can I use a 1g ecu? I think I noticed that the cases are slightly different? Can I just switch it between cases or is that a big no-no?
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
Yes, ISC shorted out causing a blown driver.

Yes, 1G ECUs are the same but have a different eprom chip, but it will run as long as it is for a 5speed. Auto ECUs are programmed for smaller injectors.

If you get a 1G ECU and want to be completely correct, Send the blown ECU and the new 1G ECU to me and I will recap, clean, and socket the new ECU and then pull the chip out of the GVR4 unit and slide it into the new socketed 1G.

And then if you ever want to do a Keydiver chip or DSM Link, your all set.
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
BTW - Sometimes a blown ECU can be fixed. If I can repair it, it would cost you $20 for labor/cleaning and $5 each for drivers. PM me if you want more info.
 

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
What would cause it to short out? I bought the isc a few months ago from autozone with warranty(maybe not the best idea?)
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
1 of the 4 coils inside an ISC shorts out or a shorted wire from ECU to ISC.
 

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Ok. PM sent and I'll check out the isc and wiring.
 

holeshotmoe

Well-known member
Joined
Apr 7, 2005
Messages
1,291
Location
MD
The chip might have already been cooked by your old ISC. The new ISC is probably fine. I replaced mine and then found the smoked driver later when I was checking the caps for leaks. There's a simple procedure to check it ISC CHECK
 
Last edited:

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Will I be ok throwing in a 1g non-eprom ecu while the original is getting repaired?
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
Yes, as long as the ISC checks out OK. If it is from an Automatic car, just drive it easy, the injectors will be mapped for 390 injectors instead of 450s.
 

Wizardawd

Well-known member
Joined
Aug 7, 2007
Messages
1,323
Location
Franklin, NC
No need to drive it easy...the AT ECU actually adds a touch too much fuel. But, it actually works out fairly close as the 1g AT 390cc were run at like 43psi and the 450cc 1g MT were at 32psi.

Wiz
 

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Threw in the 1g ecu. Doesn't start. The fuel pump won't kick on until after I get done cranking the engine. No matter how long I crank. My old ecu works but obviously the idle is eff'd.
 

ktmrider

Well-known member
Joined
Sep 10, 2007
Messages
3,128
Location
Tempe, AZ
Quote:
Why won't the 1g ecu work?



click - Maybe from a 90 and/or needs the wire swap as per link
 

stevep

Well-known member
Joined
Oct 23, 2004
Messages
416
Location
St. Charles, IL USA
There is no difference on a 90 ECU that would cause issue with activating the fuel pump. It's likely the other ECU is also damaged.

I just noticed that both ISC drivers are blown on the original. IC105 went big time but IC107 is also blown.
 
Last edited:

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
Yea I gotta figure out what I want to do. Get my original sent off and wait it out. Or just buy a known working ecu and get it socketed/chipped. Sending mine will probably be cheaper eh?
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
A spare is not a bad idea if this is a DD.
 

OMFGeofffff

Well-known member
Joined
May 5, 2006
Messages
867
Location
Burnsville, MN
I just bought an auto eprom ecu. Terry can I send my ecu's to you to switch out my old chip into the automatic? The auto is already socketed but my original isn't. If anyone knows who else can do this for let me know. Terry I'm sending you a PM too if you don't look at this.
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
I can swap things around for you.
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned

Recent Forum Posts

Top