Guys I badly need your help here. I have recently swapped my 4G15 SOHC cvt transmission engine with 4G94 SOHC and used my current cvt transmission for this upgrade. The installation went perfect and it went down on same engine foundations/mountings. I used the same ECU and cable harness of 4G15 and it went down grip to grip on all sensors except one which I got fitted from a professional guy. Used the throttle body of 4G15 as it had no difference. Initially it didn't started due to the reason that I used same camshaft position sensor which was with 4G15 as I didn't received camshaft sensor with 4G94. I talked to a Mitsubishi guy and he told me that you need to install one compatible with this engine. So I tried multiple ones and one of them worked perfectly and car started perfectly fine. Now I am not getting any check engine lights but here is the problem.

The car runs smoothly without any flaws, shifts gears smoothly but after doing around 8 to 9 miles every time the car speed cluster goes crazy up and down and immediately after doing this transmission N light starts blinking and car doesn't shifts gear. Leave the car untouched for some hours and it again runs smoothly 8 to 9 miles and start doing same.


Can any expert guide me over here. What did I missed? as I am lost here and don't know what to do. Please this is kind of urgent.

 

I'd say by you dropping a 2.0 motor into a car with a pcm that's programmed for a 1.5 is the problem.

 

If the PCM is the real problem why does the car even starts and works fine for 9 miles and than start giving problem.

 

Is your ecu from the 1.5l engine? Is it tuned or still has the stock 1.5l rom in it?

 

Yes ECU is from 1.5l engine and It has still the 1.5l stock rom on it.

 

Sounds like it is going into a "limp" mode

 

I looked into this a little bit more, it's most likely not due to the difference in motor sizes and rom(although still possible, just less likely), that would have a bigger effect on an auto transmission and not cvt. If that were the case it would go into limp mode almost instantly once the car were started up. It's most likely that the transmission is overheating after that long of a drive.

 

Problem solved guys. It was going into limp mode due to low voltage and amps and that was caused due to a small battery with less amps. Switched the battery to 70amps and problem resolved.

Now I have another question. To take out the proper juice from 4g94 do I need to upgrade 4g15 stock ecu rom to 4g94 ecu rom? Is it doable if yes how and from where can I get the rom. Are there any risks affiliated with this rom upgrade.

 

I would be careful because the CVT trans is different from our 4g94 so our rom might not work?

 

From my understanding of CVT's there are no actual shift points programmed in the PCM like with an automatic, it just takes input from a few different sensors(mostly the maf) to determine the correct gearing ratio. Like eusgen said, be very careful with that because the 2.0 doesn't come with the CVT as an option, it may do more harm than good.

 

Ive had that kind of tranny and motor (4g15) with my old lancer. Redline is 7k. I used to shift at 6500.

Just wondering why did you choose the 94 instead of the 92 or 93 mivec engines ?