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1995 Mitsubishi 3000GT VR-4
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136 Posts
Discussion Starter #121
My first go at a 3D printed boost leak checker worked for the most part, but I noticed it start to slip around 10psi... I didn't print a big enough lip for the MAF's band clamp to grab onto.









I changed up the design and have a new one printing, should be good to go by morning.





My rear turbo IC pipe seal arrived from 3SX, so I'll get that installed and see how I'm doing on leaks after that.
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #122
The car is showing up on jack stands in Street View… I think that means I’m taking too long. It’s about time for another update (almost a year later).



I printed a more robust leak checker and replaced my rear turbo IC pipe seal. Seems like the remaining leaks after that were from the throttle body shaft seals and fuel injector seals.



Fixing those leaks alone wouldn’t have knocked the car out for the past 11 months, but troubleshooting the fuel pump got me sufficiently side-tracked with engine bay wiring issues. I hooked up a direct reading gauge to the fuel rail so that I could watch pressure while driving to see if the 0/1 bit switching I was seeing in my logs was messing with my line pressure. What I found right away that tripped me up was a pressure response I was seeing in conjunction with some erroneous electrical loads. The biggest being the turn signals and brake lights: with the car idling I would have rock solid fuel pressure at 43-44 psi. Put the turn signal on and I’d get a 3-4 psi drop in sequence with the blinking of the signal (or a solid drop with the application of the brake pedal). This is also consistent with a dimming of all the interior lights when these loads are activated, which I think I’ve mentioned before in this thread.

To keep chugging along, I could have hotwired the pump directly to isolate it from the rest of the car. But with the poor condition of a lot of the weatherproof connectors in the engine bay, I thought it best to try and get them all sorted out. Hopefully this will get to the root of the problem -or problems likely- instead of just putting a band aid over the fuel pump system alone.

Oil Pressure Sender.
 

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1995 Mitsubishi 3000GT VR-4
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136 Posts
Discussion Starter #123
Knock Sensor -This one was completely cracked away on the sensor side. That’s all supposed to be shielded.



The harness side, down into the loom a bit, showed some insulation splitting too (the white wire):



I found the same stuff in the Rear O2 Sensor harness-side:

 

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1995 Mitsubishi 3000GT VR-4
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136 Posts
Discussion Starter #124
The injectors and throttle body got their service too. Here’s the report back from the injector cleaner. They weren’t too bad I don’t think, considering their age and mileage (212K).



I disassembled and cleaned the throttle body, and replaced the shaft seals and the coolant gasket. There was lots of good advice here that made this pretty painless, such as remembering to strike a line across your springs so you can wind them back the correct amount, and to grind down the peened-over throttle plate screws to help with removal.

Throttle Body Seal.


Throttle Body Coolant Gasket.


 

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1995 Mitsubishi 3000GT VR-4
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136 Posts
Discussion Starter #125
On to the re-wiring:
First off, a huge thanks to Brad at Sheridan Engineering for kitting together all of the OEM style connectors. He was great to deal with, offered me tons of advice and help, and is very reasonable on the cost for everything. Apart from the connector kit, I scrounged up 18 and 16 AWG stranded TEFZEL wire, open barrel splices, heat shrink tubing, loom, high temp electrical tape, and slowly started plugging away one connector at a time.

I pulled out the solenoid rack and started working on that first. It was nice beginning with this small harness as I was able to get familiar with the crimp connectors and re-pinning each terminal while being able to work comfortably at the bench. I was also able to eliminate the solenoid and wiring for the EGR system at the same time (Brad’s kit included pin plugs for empty terminals in the OEM connectors).







Next I moved on to the MAF connector. Once I started de-pinning this one, I was surprised to find that the wire and terminals were still in real good shape. The crimped ends of the wires had nice shiny copper with no signs of corrosion, and the insulation was still colorful and flexible under the loom. The only real bad part was the connector itself, which had a broken lock tab and wire boot retainer. So I decided to replace the connector only on this one and just moved the original wires over.





After that I replaced the old knock sensor with an OEM unit that I got from 3SX.

 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #126
Then on to the real fun stuff: making pigtails out of my new connectors and splicing them into the engine harness. I started with the end of the line that runs across the forward cylinder bank. This part contains the cam and crank sensors, the front three injectors, and an O2 sensor connector. Most of them are straight forward, I clip off the old connector, and progressively cut back along the wire until I find supple insulation and clean copper. I’m crimping all my junctions with open barrel splices, so I strip away about an 1/8th of an inch from each wire, dab it in dielectric grease, then crimp it and heat shrink it.











The O2 sensor was a pain in the ass because two of the four wires are a shielded pair. It wasn’t hard finding the replacement wire, but pulling back the shielding braid, crimping, shrinking, re-meshing the braids, and shrinking again made for a lot of layers. It all managed to remain nice and flexible though, so hopefully it won’t give me any problems down the road.









Which is where I stand today. The front portion of the harness is complete with tape and loom, ready to go back in the harness holder –after I 3D print a new one.



I still have to do the rest of the connectors hanging on the bracket near the thermostat housing, along with the TPS connector, and the rear fuel injector connector and sub-harness. After that, I’ll have a boost gauge and fuel pressure gauge that I need to run to the cabin so I can monitor those once I finally get the car off the stands and start driving again. Fingers-crossed that’ll happen before the Street View car comes through my neighborhood again.
 

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Great inspiration and perseverance on the vehicle. It's great to still see people heavily involved in these cars and its even better for newer guys like me who is starting to jump into to see stuff like this. Can't wait for the day you finish!
 

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Well done, nice to see!
I noticed that you labeled the white wires with the color they replaced. Just a heads up to make sure that label does not fade with time/heat/oil :)
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #129
Great inspiration and perseverance on the vehicle. It's great to still see people heavily involved in these cars and its even better for newer guys like me who is starting to jump into to see stuff like this. Can't wait for the day you finish!
Thanks man. I can't wait either. There's a lot of competing priorities going on, but there's also a lot of laziness on my part. I shouldn't be going to bed before 10pm on a Saturday while there's still work to be done:)

Well done, nice to see!
I noticed that you labeled the white wires with the color they replaced. Just a heads up to make sure that label does not fade with time/heat/oil :)
Yeah I was sure to make all my labels on a laser printer, that should keep it from fading over time. I actually have a big sheet of them I made in Excel, I use an exacto knife to cut them out one at a time as needed. We'll see if the clear tubing I picked stands the test of time. I was sure to buy Raychem for the black stuff that is actually supporting the wire spices, but the clear that I found was just the Chinese Special on Amazon.
 

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1G Foglights b!tches
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Impressive!
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #132
I kept clipping back a bunch of the oil pressure switch wire to find un-corroded copper. Which means I had to tear into the intake and coolant lines so I could access more of the main harness. Removed pre-turbo pipes, rear turbo intercooler pipe/hose, radiator lines, coils, front bank plug wires, and the PTU.


After that I was able to get all three wires for connector B-06, which has the oil pressure switch wire, oil pressure gauge unit wire, and power steering pressure switch wire.


Lots of cleaning followed as well. It looks like all of the camshaft endcap seals are bad, so it’ll only be a matter of time before it gets all dirty again. I’ll live with those until it’s time to do the timing belt next.


While I have all these parts out, I’ll rerun all the vacuum lines as well since a bunch of them are still the originals.
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #133
Messing around with the vacuum lines and I came across an open port on the gearbox. Does anyone know if I'm missing a plug here? Is this just an inspection port for the clutch?


 

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Looks like fun. Lol


Sent from my iPhone using Tapatalk
 

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1995 Mitsubishi 3000GT VR-4
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136 Posts
Discussion Starter #136

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #137
Wiring just won't quit! So many connections...
Rear fuel injector harness.


Main harness.



Finally completed this one. That's is all the sensors/injectors running across the front cylinder bank, all the sensors up around the throttle body, on the gearbox, and up to the solenoid rack. I still have a few more to do along the firewall, but almost there. Then I can start putting everything back together!


She's daddy's little helper now. Pretty sure she couldn't walk when I put the car up on stands for the re-wire :)
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #138
There’s a few connectors left in the kit that are not installed, but the original factory ones still look like they’re in good shape, so I figure it’s best to leave them at this point. Which means I’m finally turning the corner on this maintenance “session” and actually putting parts back into the car. I rerouted the main harness and attached it to its keepers on the gearbox so it’ll remain clear of the shift linkages. I also took this opportunity to install the PTU and coil pack, since I remember how much of a pain those are once you have all the air and coolant lines in place on that side of the motor.



Before it got too crowded with bigger pipes and tubes, I also replaced the four vacuum lines that lead to the front turbo wastegate and all the EVAP equipment. I’m using some thick-wall, high-temp silicon tubing from Amazon. Hopefully it’ll last another 25+ years. I was actually surprised, all of the original tubing in this region was still nice and supple and without any apparent cracks.



I was able to get a good look and feel on the impeller of the forward turbo as well. Looks to be in real good shape. No oil, no shaft play at all, and no FOD hits on any of the blades.



To wrap things up in this corner of the engine bay, I attached the new connectors to the plugs on the PTU, coil pack, and coolant sensors in the fill tube body. Made sure all my blue rags were pulled from each air/coolant line, cleaned up the incoming lines, and brought in the upper and lower radiator lines, and the cross tube from the driver’s side intercooler.





That’s it for now. Pretty happy about bringing parts back in. Next is to setup the parts washer so I can get cleaning on the upper and lower intake manifold. I want to place the upper manifold with the throttle body into position so I can do a one-for-one replacement of all of those vacuum lines next. I won’t be installing it permanently at this point as I’m going to want to run the motor over a bit with all six plugs out so I can get the oil system primed up before the initial start. Will be a good time for a compression check as well.
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #139
Got the parts washer setup for cleaning out the manifold set –it would have been nice to have this up and running a few years ago when I was pulling the dirty sub-frame braces out of the car.


Then I dropped in the lower intake manifold, installed my cleaned fuel nozzles into the rail assembly, then wrapped up all the fuel connections. These parts should be in for good now, so I used all new gaskets and torqued everything to their final values.


I started positioning the upper manifold assembly, and realized my Ninja Performance fuel rail pressure port needed a chamfer added so that it would clear the runner to cylinder six.


Once I had the clearance needed, I installed the upper manifold and throttle body, so I could check out how I did on all my rewired connector lengths as well as replace all the original vacuum lines.



I looks like all the new wire connectors will reach their sensors, which is a huge relief because I really didn’t want to go back to wiring. The upper manifold is only in temporarily for now so I can get a proper fit on all the new vacuum lines. Once those are all replaced, I’ll pull it back out, take out all the plugs, and do some motoring with the starter to prime up the oil system since it’s been down for so long. I’ll also take the opportunity to run a compression check before installing the upper manifold for good. She’s getting there!
 

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1995 Mitsubishi 3000GT VR-4
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Discussion Starter #140
Back to it the past few nights: I installed the battery and the MAF/filter assembly, re-fogged the cylinders in prep for motoring with the starter, and drained the fuel tank. I started drawing out the old gas (it has been sitting now for ~2.5 years) through the fill tube with a hand siphon and only pulled about three gallons out before it started running dry. I figured I was near the end of it, but turns out the siphon never made it much past the elbow in the tank. I ended up pulling almost 15 gallons out through the tank drain plug. This wouldn’t have been a big deal, but having to do it under the car and starting and stopping the drain several times along the way to empty out my catch bin made a huge mess.



After that was all cleaned up I loaded five gallons of fresh 93, and purged over a gallon of that through the lines to the fuel rail connection point by jumping the fuel pump. I made sure to collect and discard all the old stuff from the lines without letting it get into the rail loop since my refurbished injectors are already installed. After the system was completely purged, I buttoned it up and attempted a pressure test. I’ve got a gauge pressure line routed into the cabin. A quick jump of the pump again showed around 80 psi at the entrance of the loop with no injectors firing. I believe 40-50 psi is what the FPR is supposed to govern when things are static. After disconnecting my jumper wire to check things out, I noticed I had gas leaking through the diaphragm and into the vacuum port on the back of the regulator. This is the original FPR, so I’m guessing sitting dry for over two years finally wore out the internals so they couldn’t hold back the pressure anymore. I had an aftermarket Intermotor brand one from Advance in supply that my dad had tried years ago as a fix to the running issues. When he didn’t see any difference in the way it ran I think he put the OEM one back in and kept the one from Advance as a spare. However, it leaked even worse than the first one. I suspect that once these units are exposed to fuel on one side of diaphragm, they can’t sit unpreserved for long before they start to degrade. I only hope now that I didn’t hurt the solenoid since it got flooded as well once the vacuum line started taking on fuel.



Which means I couldn’t go as far as to start the car yet. I topped off the coolant (the Leslie no spill funnel is awesome!), pulled all my blue rags, removed fuse 12 from the cabin so the fuel pump and PTU wouldn’t energize, and cranked it over for a few 20-second runs to mix up the oil and ensure that oil pressure was building on the gauge. I don’t have the plugs in yet, so the cranking is effortless for the most part. With this done at least I know I have a primed and redistributed oil system, fresh fuel, and full coolant, so I should be in good shape for the first start once I get the FPR replaced.



Last thing to do for the night was to put in a set of new spark plugs, route and connect the ignition cables, and tidy up a few more hose and cable routings going over the gearbox.



I’ve got a new aftermarket FPR on order with O’Reilly, which should arrive in a day. I hope it works well enough to get this thing back on the road. I’ll consider it temporary as I need to upgrade the fuel lines from the filter since they’re all still original. I figure I’ll go with a good aftermarket FPR setup and replace all of that as a kit. In the meantime I’ll work on installing the upper intake manifold, throttle body, and the rest of the pipes for all of the charged air lines. Fingers crossed I can have a successful first start in the next couple of days!
 
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