Auto GSX 2.3L with Genesis Coupe 2.0T Pistons

[DSMPT]

I started replacing the heater hoses, but ended up doing below.

- Replaced Heater hoses
- Replaced Brake booster hose and check valve
- Replaced Throttle body coolant lines
- Replaced Fuel feed line from filter to rail
- Replaced Fuel pressure regulator return line
- Replaced Intake manifold with EVO 2
- Replaced Injectors with 560cc
- Cleaned water/methanol injection nozzle and nitrous jets
- Switched the nozzle location between the water/methanol and the nitrous.

 

[GIB]

You are a mad scientist!
This can come in handy if we run out of options. (Likely with how hard it is to get parts anyway, thanks Mitsubishi )

 

[DSMPT]

They started to open stores where I live in Mexico since last year. Just stopped by after pumping the gas.

 

[DSMPT]

Engineering Sample 2g ECU.
I have seen some engineering sample ECUs for different Mitsubishi cars before but this is the first time I see one that is DSM specific.
This is a prototype of MD313046 which is the Japan spec turbo 95-96 ECU. I have a MD313046 as a spare and by comparing both, it's interesting that the motherboard is totally different. And I know that the Japan spec ECU is non eprom and has the same motherboard as EVO 4 ECU, but this one has a totally different motherboard with EPROM and a 30 pin connector. It's labeled as "Gain 1.5", I have no idea gain for what, and unfortunately I have no method to read the code. But the ECU itself seems working as it should. It just started my 2g.

 

[DSMPT]

It rained unusually a lot last summer and it destroyed the streets and still terrible condition, so I haven't driven my DSMs. A few days back I moved the 2g to clean the garage. Nothing happened at the first attempt to crank, just heard the fuel pump priming while cranking. At the 2nd attempt, it cranked and started but I felt the starter spun a bit slower than usual like with a weak battery. Next day when I checked, it didn't crank at all, even no clicking sound. Thought the starter relay went bad but the starter was getting the signal while cranking. It was simply time to replace/rebuild the starter.
Found a cheap new starter at a local parts store, the store told me that it won't fit with a turbo 4g63. Because the manufacturer doesn't show GST or GSX. but it showed 2g Eclipse 2.4 auto. I was sure that they are the same, so I just bought it and removed the old one and compared. Yeah they are the same and it's strongly cranking again.

 

[fwdmaster]

For a change of pace, planning to put the 2g back as it was before. With the JDM taillights, early EVO intake manifold, stock 2g exhaust manifold w/ ARC heat shield.
View attachment 720857
View attachment 720859

Looks awesome ,that arc heatshield looks so cool!

 

[DSMPT]

After replaced the starter, recently at the cold start, something has been making the idle unstable sometimes, obviously one or two cylinders have no or miss fire but if I keep sending the gas a bit to avoid engine stall, shortly the idle gets back stable and run as it should. And this happens mostly at the first attempt when the engine is cold. Confirmed that all cylinder had good spark and fuel. When it's not happening I ran a leakdown and compression test, all good, all cylinder has 245-255 psi compression when hot.

Next day after the compression test, it got crank no start, and I could easily realize by sound that there was very low or no compression while cranking. I cranked by hand and specific cylinder had metal snapping sound at certain degree like some compressed valve springs snap back or flex plate bolt contacting something.

The first thing came up to mind was bent valves as the piston to valve clearance is tight on this engine, but I was almost certain that it couldn't be since the timing is good and the leakdown and compression test result was great when I cranked last time.

Next thing came up to mind was valve train components failure, like something is wrong with lifters, valve springs or valve guides. I removed the valve cover and found some cylinder's intake side lifters that are in the base cycle were pumped up which mean those intake valves were open for some reason when they should be closed.
I was gonna to remove all the lifters by the removal tool to clean and bleed down. I found almost all intake valves don't go down naturally while I was prying the springs down. If I heated the valve stems by a heat gun for few seconds, the valves started to move. I guess that something is wrong with valves to guides clearance, mostly the valves and worn guides are gummed up by tar or so. Seems like the sound I heard was from compressed valve spring snap back and sudden valve shutting in the middle of base cycle. Anyways it's time to rebuild the head.I will remove the head soon.

It's also time to try to use a 2g 7 bolt tensioner on the 1g 7 bolt. And I will report back.

We can see only one of cylinder #1 intake valves is slightly open. This now happens randomly in any cylinders but the valve will naturally come back to shut by time or when gets hot. It was good that I could find before smashing some valves.

 

[Ineedboostman]

This just happened to me recently when I got my Talon running after it sitting for years. It only had a half tank of old gas so I figured it would be fine to burn it off and put fresh in but it gummed up the intake valve guides and threw two rockers. Hoping It didn't bend a valve but I haven't had the heart to dig back into yet after that happened.

 

[Car Cannibal]

Hey Hiroshi, another custom engineering project you got and pulled off here.

People think I'm nuts for starting my cars every 2 weeks when possible to stop the sitting and shitting I call it. After you've driven in Taxis/Ubers/Limos etc and they're all 200k+ mileage in only 5+ years and 300k+ after 10 and they're all still running well with limited part repairs you realize you gotta start these things or parts rot/seize etc.

 

[DSMPT]

Removed the cylinder head and did a quick inspection.
Most of intake valves are kinda more or less stuck, I couldn't push down the intake valves flawlessly by finger even without valve springs but they moved if I heated a little bit by heat gun and lightly tapped. But sure not smooth as they should.
All intake valve guides have excess carbon deposite buildup inside as expected and causing the intake valves gummed up. Removed the excess carbon inside of few guides by a reamer and the valves started sliding smooth as they should.
All valves are straight, so measured the valve to guide clearance. Some are slightly in loose side but almost all are within the factory spec range like when I inspected last time when I built this engine 10 years ago.

Looks like a good cleaning would still be ok, but I would fully rebuild for another 10+ years of use. I think it's a good time to do the things I was planning.

I would probably do :
- A full cylinder head rebuild.
- Repair and make all exhaust studs thread to M8. Some M8 thread have been drilled and tapped for 3/8 SAE by the previous owner. I have been lazy to do this by removing the exhaust manifold and radiator.
- I will go with much thicker head gasket to give more piston to valve clearance to allow me to run higher lift aftermarket cams in the future in case if I would want.
- Change back to the stock 2g exhaust manifold and ARC exhaust manifold heat shield from the FP exhaust manifold and the Extreme PSI exhaust manifold heat shield
- Also change back to the EVO 2 factory O2 housing from a screamer that was kinda making me embarrassed a little bit when boosting.
- I have a good set of the factory late EVO's beehive springs and retainers in the storage, so I will install them instead of putting back the old 2g stock springs.
- I will try to install the 2g 7 bolt tensioner and 2g arm.

 

[DSMPT]

I just started working on a 2g/EVO 7 bolt tensioner in 1g 7 bolt.
While I was mocking up the 2g tensioner arm in the 1g engine, I used a 6 bolt spare parts engine that has been on a stand because it's easier and the 1g 7 bolt and 6 bolt use the same 1g water pump, so I can check interferences. Not a direct bolt on but it seems like we would be able to make it work in a 1g 7 bolt.
And I actually realized that we could make the 2g tensioner work in a 6 bolt like the pics too. In case if a 7 bolt tensioner would work in a 6 bolt engine, we wouldn't need to be worried about the 6 bolt tensioner gets discontinued. (I am not sure but perhaps it wouldn't work if you have the Kiggly crank trigger)
I can't be sure about anything yet until making the engine actually running. I will report back once the cylinder head comes back from a machine shop.

 

[DSMPT]

I went to pick up the cylinder head, resurfaced, replaced the valve guides and cut the valve seats. Passed a vacuum test, but anyways I always disassemble to inspect by myself. And I will lap the valves if necessary. Found the valve to guide clearance came too tight especially exhaust side. I will re-ream or hone a bit more by myself to adjust it.

The pic below is the thickest Cometic off the shelf head gasket. It's like 3 times thicker than the factory thickness I will use it this time.