1995 Eclipse GST

[Lintu]

This is the Build Thread for 1995 Eclipse GST. Reply below.

 

[Lintu]

Update on my 1995 Eclipse GS-T (Imported to Brazil).
I’ve been bringing the car back to proper OEM mechanical condition after a LOT of previous-owner “creativity.”
Here’s everything I’ve done so far:

ECU / Electronics

Installed a new 27C512 EPROM with the stock 1995 GS-T bin, burned using a TOP2049 programmer inside a WinXP VM. (TKS @steve )

Original EPROM chip was preserved; socket was present and intact.

After installing the correct bin, OBD2 started working perfectly, and I can now log everything through Torque.

TPS was misaligned — corrected.

 

[Lintu]

Sensors / Engine Management

Replaced the front O2 sensor (pre-cat) with a proper 4-wire unit.
The previous one had spliced wires, incorrect heater connections, and wasn’t working.

CEL (P0135) is gone.

Cleaned the MAF and MAF CEL is gone.

 

[Lintu]

Fuel System

Removed a sketchy T-fitting that fed an aftermarket in-cabin fuel pressure gauge.

Installed a new FRAM fuel filter.

Added a 5/16" straight connector from filter to rail, restoring OEM-style routing.

No leaks and fuel delivery feels smoother.

Fuel pump does not prime at key-ON — still verifying if this is normal on a 1995 ECU or related to the charging system.

 

[Lintu]

Ignition

Previous owner was running mixed plugs (BKR6E + BKR7ESB-D).

Installed the correct copper NGK plugs (OEM heat range).

Still trying to find good spark plug wires to replace.

Had oil leak In valve cover, caused by bolts being literally finger-loose.

Tightened all bolts properly and the oil seepage stopped completely.

 

[Lintu]

Intake / Throttle

TPS is now calibrated and reports correctly.

Throttle cable wasn’t reaching full travel — adjusted pedal end to get full range. Probably, the cable is not originally meant for a 2GDSM and is too long. Will replace it eventually.

Idle quality improved after TPS fix.

 

[Lintu]

Vacuum / Solenoids

FPR solenoid and wastegate solenoid were bypassed by the previous owner.

Currently running straight turbo → actuator, and straight manifold vacuum to the FPR.

I plan to restore the OEM vacuum routing once I source new hoses.

 

[Lintu]

Cooling

Cooling system was bled, previous owner ran it with tap water ( oh god.. why? )

Replaced with correct coolant

transmission side fan works correctly, the car cicles the fan correctly with the temperature.

A/C Fan is not installed. Previous owner took it out because previous fan melted for some reason.

The car is not overheating, but I still need to install it back ( I have the fan. It was in the trunk when I got the car ).

 

[Lintu]

Electrical / Charging System

OBD logs show low charging voltage (13.0–13.6V while driving).

Interior/exterior lights flicker at idle.

Strong suspicion of a weak alternator or failing internal voltage regulator.

My plan is to measure alternator, and, If low, I’ll try to service it (brushes + regulator + rectifier).

 

[Lintu]

Drivetrain / Clutch

Clutch engagement point was drifting upward, to the point of not being able to put it in gear. Adjusted the master cylinder rod inside the cabin.

Still unsure whether master/slave are worn, but they currently hold pressure and operate consistently if i adjust it to the very end of the pedal, meaning i have very little cluch course in the pedal (as if 90% of the pedal course is dead)

Trans mounts appear blown. Probably the cause of harsh shifts and drivetrain lash.

 

[Lintu]

Miscellaneous

Removed a very questionable “brake cooling” contraption made from a plastic bottle and hoses zip-tied under the car.

Cleaned old electrical tape, splices and cut wires.

Found two thin cut wires (brown and black) near the coolant pressure cap area, leading into the cabin. Im still tracing what they belong to (alarm/anti-theft maybe?)

 

[Lintu]

Well, I think my alternator died.

Got battery light on while driving out of work. checked and got 11V on the battery terminals.

I got the alternator out, and im trying to understand how to bench test it. Any thoughts?

Should the car start with no alternator ( only over a known charged battery )?

Thanks!

 

[Lintu]

Hey guys, quick update on the charging issue:

My car died while driving a few days ago. The battery light came on, the brake warning light came on too, and voltage kept dropping until I had to limp it home running only on the battery. The next day it started normally a few times during testing, but eventually got harder and harder to crank, until it wouldn’t start at all.

With the alternator out of the car:

Lamp test on the L wire was working (bulb lit with ignition ON, turned off when spinning)

But the alternator output never rose above battery voltage

Even after installing a new regulator and rectifier, the alternator still wouldn’t charge

At that point the OEM alternator was confirmed dead (regulator + something else).

Backup alternator attempt

I had a used Pajero/Montero alternator that looked identical internally but had different mounting ears.
I swapped the ENTIRE internal assembly (rotor, stator, rectifier, regulator) into the original Eclipse housing.

Tried testing it at home with a cordless drill — rotor excited, lamp went out, but output stayed around 12.1V, so I suspected the drill wasn’t giving enough RPM.

Took the Frankenstein alternator to a professional auto-electric shop.
On a proper belt-driven tester:

It charged perfectly: 14.2V
Output stable under load
Regulator and rectifier confirmed good

So the swap worked — the Pajero internals are fully compatible with the 2G Eclipse when installed in the DSM housing.

Even with the good alternator installed, the car still wouldn’t start.
Spray-fuel made it fire, so I checked the fuel system:

Fuel line was only dripping

Pulled the pump assembly: Pump was completely rusted and dead

Luckily the previous owner had left a brand new fuel pump in the trunk

Installed the new pump and added ~5 liters of fuel directly into the tank bowl.

Fuel pressure returned immediately

After that, the engine fired up and ran strong.

14.2V while revving

13.5V at idle with headlights + radiator fan on

I’m still replacing the battery (voltage drops too fast during crank), but I think everything else is working perfectly now!

 

[Lintu]

Hey guys,

Just wanted to share a real fix for a very common (and confusing) 2G DSM speedometer problem, in case it helps someone else.

Symptoms

Speedometer needle almost dead

Only barely moves off zero (or stops around ~20 mph)

OBD vehicle speed is correct

Odometer and trip meter work perfectly

Cruise control does not engage

RPM, fuel, temp gauges all normal


This makes you think VSS, wiring, ECU, etc… but none of that was the problem.


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Important diagnosis

VSS signal was confirmed OK (OBD reads speed correctly)

Odometer uses the same VSS signal → since odometer worked, VSS was not the issue

Speedometer motor (air-core) measured 150Ω / 150Ω on both coils → motor is GOOD


So the problem had to be inside the speedometer electronics, not the sensor.


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Root cause

Inside the speedometer module there is a small PCB that drives the air-core needle motor using a proprietary Denso ASIC (mine marked SE125).

One of the small electrolytic capacitors (6.8µF) in that circuit had failed.

Out of circuit measurement:

Initially reads ~5µF

Then drops to ~800nF

Then goes open


Classic dried / failing electrolytic.

Because this capacitor is part of the signal conditioning / gain network, the driver IC was still “working”, but with almost no output current, so the needle would only barely move.


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The fix

Replaced the bad 6.8µF electrolytic with a 10µF (higher voltage, 105°C) capacitor

Reassembled the cluster


Result: Speedometer works 100% again
Needle moves normally
Cruise control works again

No VSS replacement, no ECU, no wiring repair.


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Extra notes

The two large capacitors in the module are for the odometer motor, not the speedometer needle

The critical ones are the small electrolytics near the speedometer driver IC

If one failed, the others are probably close behind → good idea to recap them all

The ASIC itself is almost never bad



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Takeaway

If your 2G DSM speedometer:

barely moves

but odometer + OBD speed are correct


* Check and replace the small electrolytic capacitors in the speedometer module
It’s a 30-year-old electronics problem, not a sensor problem.

Hope this helps someone

In case anyone needs reference for the speedometer repair, here is the bad capacitor:

 

[Lintu]

Hey Guys!

Another day, another problem in DSMland!

The alternator/water pump belt snapped mid-drive ( lighting up the dash lamps just like my christmas tree), which stopped coolant circulation and caused a brief overheat.

What happened:

Belt failure, water pump stopped, alternator stopped, PS stopped.

I was close enough to bring her back home.

Just as I parked, shut her off and opened the hood, coolant boiled and was expelled through the expansion tank drain (not the radiator cap).

Let her cool down and checked coolant and oil levels.

Oil was fine, but she lost coolant ( empty expansion tank )

Fix:

Replaced all three accessory belts:

A/C
Alternator / Water Pump
Power Steering

Refilled coolant (I calculate she lost ~3L during boil-over...)

Bled the cooling system

Results:

Engine starts and runs perfectly

Fan cycles normally (ON ~100°C / OFF ~95°C via OBD)

No coolant pressurization issues

No oil contamination

No abnormal noises ( at least no NEW ones )

Conclusion:

Overheat was circumstantial, caused only by the broken belt.

Belts were old and worn out.

No head gasket issues, no internal damage.

Car is back on the road (for now )

 

[Lintu]

Hey guys,

Just a quick update:

While going through the spare parts that came in the trunk from the previous owner, I realized I actually had everything needed to recirculate the BOV, even though it’s not the OEM one (the car was running VTA when I bought it).

I went ahead and recirculated it back to the intake, and the ECU seems to like it a lot:
MPG went from “HELL NO” back to normal

Throttle transitions are smoother

Shifts feel noticeably cleaner

Idle was already OK before, but the overall drivability improved after recirculation.

Only downside is… no more PSHHH between shifts

But honestly, I’d rather keep it stock and let the ECU be happy for now.

 

[Lintu]

Hello guys!

I’ve reinstalled the factory cassette/radio + CD units.

Thanks for keeping them, previous owner

Can’t beat that orange vibe!



The unit had a ton of cold and cracked solder joints on the PCB, so it took me a good four or five days to get everything working perfectly.

I also ended up wiring a brand-new harness, with both male and female connectors, since the previous owner had cut the OEM female connector.

I’m still missing both front/dash speakers, but it already feels great to blast some old K7 tapes!

Cheers!

 

[Lintu]

Hey guys!

Just wanted to share a few interior photos of the car as it sits today.

From factory, the interior was fully gray, but at some point a previous owner went for a two-tone change, reupholstering the leather parts in cream — seats, armrest, portions of the door panels, etc.

Even though it’s not 100% factory anymore, I think the contrast works really well and gives the cabin a lighter, more upscale feel, while still keeping the overall OEM vibe.

I’ve been slowly bringing everything else back to period-correct details (radio, lighting, trim), so it’s nice to see how the interior has its own story along the way!

Sharing a few pics below — hope you guys like it!

 

[Lintu]

Now, some exterior photos!

It is slowly getting there!

Cheers!