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Tomble's 1983 Mitsubishi Starion GSR-X ultimate beginner restoration/fumbling


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Getting the engine started is a milestone I want my partner to be there for so putting it off until the holidays when we have the time.  So in the mean time let's take a look at our fuel system.

I read that fuel drains slowly so I didn't bother to raise the back of the car to fit jerry cans/buckets under, instead opting to just use a pan and ice cream container and swap them over.  This went poorly...  But at least I didn't roll a 1 so the garage and everything is intact and I just have to deal with the fact that I need to keep all the doors open for a while.


Also poor: my preparation.  I bought a 10L jerry can and for some brain fart reason decided that is all I'd need.  I had a couple more litres than would fit in it so I threw it in an old container and let it evap outside until I could get another one. 

15 year old fuel smells and looks pretty bad.  My old container was dirty so I was hoping that the crud at the bottom was already there. Foreshadowing



Fast forward to weekend: Partner is over!   I want to see what is borked and what can be cleaned and re-used.

She removed the wheel and dropped the fuel tank after a bunch of dirt/fuel to the face. What a trooper.


I disassembled it and found probably the first truly effed functional pieces of the car.  



I'm actually shocked at how bad this has rusted.  It's like the rust has generated its own cities and infrastructure on these tubes.  This float mechanism is truly beyond hope.




I was hoping to be able to clean the in-tank filter and re-use it, but it's $15 from amayama and it looks like I'll need to find some other bits too so shrug emoji.

I gave the tank a quick zhuzh with a smol brush and left it outside to tackle another day.  I can hear debris shift around when I tilt it. A brief shitty look inside is inconclusive - definitely some rusty bois floating around in there but not sure what the tank itself looks like.  The exterior has some minor surface rust in places, hidden under the geological layers of dirt.  It sucks that the holes are so small, definitely won't be able to get my arm in there to clean it properly, so we may have to wait for some solvents to arrive courtesy of partner's chemistry connections.


As a side, the paint around the drain hole peeled off from the fuel.  Seems like a design flaw... also the fact that the heat guard can't be removed so treating up in there is going to be "fun".



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  • 2 weeks later...

After some googling and video watching I figured a few things out

  1. the click is the relay near the ECU in the passenger side activating, and this click means that relay (and the electrical system) is probably all good
  2. there's a control terminal on the starter solenoid which is meant to have a cable going into it :shock:

Here's the ECU, being good looking


But our starter only has the one cable actually:


Also it's really hard to see back there, that's a camera shot because there's no actual line of sight to the back of the solinoid. 

... Wait what's this?


Sure enough there's a dangly boi in the engine bay that slots right on (hard to do when you can't see it!).  The prev-prev owner must have removed it with dizzy etc.  So we plugged it in and gave it another ignition test...

... and no dice.  But the solenoid activates!  Hallelujah - that means it's not an electrical problem!

After much fandangling with next to no space and funny angles under the car, partner manages to get the two bolts undone to haul the starter out.  Here she is standing in triumph.


We gave it a quick test on the bench by grounding the case and 12v'ing the positive terminal, then bridging the control terminal with a screwdriver.  The starter clicked and whirred into life.  Probably still bad but an interesting turn of events given that the motor wasn't spinning at all inside the car, even after some hammer hitting.  So we chucked it back on the car, first just with the wires attached (it spins when ignition is turned, hooray?), then with it properly seated, and gave it another whirl.

It struggles, hard.  The battery's CC rating is fine, and doesn't drop below 10.4v while cranking.  I doubt that's the problem.

The starter also still randomly fails to engage sometimes.  So I think the reason it's struggling is just that it's old and shitty.


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The spec for the spark plugs is meant to be 0.8mm according to the interwebs.  Ours are all over the show so I bent them back into shape which won't help now but may later, especially because I don't want to put fresh plugs into the engine with the #3 threads being what they are.



Before compression testing I decided to get in there with a cheap endoscope (I got it because there are so many times I wish I had a better angle on stuff that's obscured, see: starter solenoid).  Angling it is hard because it's just on a normal electrical cable.  I'm smart so I only took 3 pics and didn't label them, so here's 1/4 of the sides of 3 random cylinders. 




I guess the harsh line is the end of the head's travel, the coffee grounds are metal filings or carbon deposits, and the diagonal scratches are factory boring marks.  When I google "worn cylinder wall" I get a lot of pictures of prettier looking walls though... :X.  How bad is it doc?


Compression testing is all over the show.

1- 158
2- 103*
3- 130 (carefully threaded on)
4- 120


I did #2 first and since it was such an outlier I went back to it after lubricating to get 120 psi, supposedly different readings before and after lubrication means worn piston rings.  This is my surprised face: :tongue:  






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  • 3 weeks later...

So of the three high pressure fuel hoses it looks like two have been munted over the years.  This time it's the one at the rear that connects the fuel pump to the metal fuel line running to the front, and it has two holes in it.  As the video above shows these holes do a fantastic job of high-pressure sprinkling fuel all over the show.  It even got into the wiring sheath on the fuel pump.  Won't have to pull those weeds for a while at least.



The good news is the L&P bracket is holding up great, Tom 1 Mitsubishi 0.

Rather than head over to hydratech again I decided to give repairing this one a go myself first.  This meant going out and nabbing a vice (been meaning to get one) and a cutoff tool (which will be handy for some other things too and also meaning to get).  I've already got the fuel hose and clamps.  I saw a guide a guy made removing extremely similar ferrules from a hose, he used a much smaller dremel but I'm hoping I can skip that and get away with the cut off tool.



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I got away with the cut off tool.




Not too much drama and air tools are fun :)

(I later moved the clamps a little closer to the ends)

But when it came time to re-assemble the banjo onto the pump, I noticed that there weren't any crush washers previously.  @ProZac confirmed that there should be some and that the (checks notes) "pulsation dampener" side's washer has some cutout bits to allow fuel to flow out of the dampener and into the banjo fitting, I had some extra copper washers that were large enough but didn't have these cutouts:


It should look kind of like this:


Or this:



The gouges are not ideal but that's what I get for being a dumb and holding it steady with raw pliers.  Better than nothing.

I marked the notches of the dampener on the outside with vivid so I could line it up with the copper washer and installed. 




My neighbour was over and implored me not to tighten it "too much", shouldn't have listened. 


While the washer is definitely not an amazing washer it still should have been tightened/crushed a lot harder.  But my hose fix works perfectly!

So after mulling whether I really wanted to take it all off and mess around with it again I decided instead to just get some goggles on and tighten it further in-place.  I still didn't really go as far as I could have but I took it to "acceptable dribble".


Then I went and did some checking of things :)

The good

  • Revs and speedo work, not sure if boostometer works
  • No dashboard warning lights (suspicious)
  • Heater works
  • Brakes seem totally functional - at low speed :P
  • Able to go into drive/reverse and move forward and back without drama, she wants to move - at low speed...
  • After 5 minutes the fuel dribble stopped entirely...?? I'll take it

The bad

  • A/C didn't kick in at all :(

The ugly

  • When done messing around I let the turbo timer do its thing for a minute while I inspected the exhaust and stuff.  After the engine shut down I noticed some very whispy smoke coming from the turbo area.  Not enough to capture on camera and I couldn't trace it to an exact area.  Giant shruggy shoulders but I assume stuff shouldn't be smoking.


I think that mostly concludes what we wanted to do with the engine.  Next couple weeks will be less exciting as I'm waiting for my partner before we do anything else (ie. take it for a spin).  After that it's stripping time...

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  • 2 weeks later...

Partner is down so we took it out for a short legal drive on private roads.

I'm not sure what to point at, but it took a bit of pedal for it to get into second gear (as a reminder it is an auto) - so for a while it just sounded like a very taxed engine moving at 15km/h.  I didn't push it very hard because while the brakes seem fine I wasn't willing to find out how good they'd be if I really needed to stop in a hurry.  We were brave enough to take it down a short steep hill section of private road and it reaaaally struggled to get back up it at about 5km/h (but fortunately did ':D).  

So there's either a power issue or a transmission issue, or both... but we've decided to investigate/solve these problems as we reassemble rather than hold up the stripping process.

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