1990 Eclipse GSX AWD Revival

[t0ny]

Removed the tank and it was as bad as I thought, maybe a little worse. The rear frame cross brace is pretty rusty, two of the three bolts are missing/loose and several spots are pretty thin. The left side isn't as bad but still rusty. It would probably take some clever welding to get reinforcement in place for the tank bolts. The side you can't see (frame facing rear is very clean).

The tank is poor condition with one good size rust "crack" and leaking at the seam due to rust. I'm not sure if those can be sealed up or if it would be better to search out a replacement. It's hard to imagine a junkyard tank in the midwest would be much better.


rear frame cross brace (and loose/missing tank support bolts)

gas tank rust, leaking seam and rust hole

Rust above rear diff, passes the screwdriver test

 

[t0ny]

So, looking at the above (I can get better pics if needed), I need some honest advice: The rear cross piece is concerning, there may be enough metal to put in some reinforcement but it would be difficult for sure. Thoughts?

The tank is rusty on the inside, which can likely be dealt with but there's a crack which may be patch-able and a seam leak. We have the tank doing a vinegar soak to see if it can help with some of the surface but we'll probably need something stronger. Sloshing it around, we found the seam leak. That is all concerning as well

Those are the two big hurdles right now and you can probably guess the condition of the sending unit from the photo above. That's probably the worst of the rust that I've seen, it's probably not insurmountable but definitely gives me pause to think about what we can do (budget is NOT unlimited) versus what we expect to get when its done as we haven't even really touched the drivetrain much. All advice appreciated.

 

[Mech Addict]

Ouch! Rust on the unibody is something that can’t simply be replaced like other parts. So not to jump past your current concerns, but it seems like you need to assess all the frame rust in total to understand just how big a mess this is. At least at a scoping level. Particularly at structural points.
The rust you showed isn’t beyond repair. It’s an area that’s pretty well hidden, so functional is good enough. How are you with a mig?

The tank is a bigger deal. Finding a donor is near impossible. Fixing that is going to take a lot more than vinegar. I’ve used the kit from Eastwood on two projects now. It comes with phosphoric acid as one of the steps. Stopping the rust on the outside will also be key, so it doesn’t get weaker after the inside is sealed. I assume they make some gas tank repair putty for small holes; luckily I didn’t need to find out.

 

[t0ny]

Well the good news is I found a local place that refurbishes gas tanks. I don't think it's too far gone so I'll take it over for an assessment to see what can be done. The frame is another task. I don't weld so I'd need to get someone to come out to assess.

One question, our fuel sender is pretty rusty and scaly but appears to be all there. I assume the fuel pump is shot but is there a bench test for a sender? Apply 12v and voltmeter? Thanks!

 

[Mech Addict]

Its a simple variable resistor. Just use an ohm meter. I can’t recall the range off-hand. Its in the FSM. Somthing like 5 empty to 110 full ohms, but that might be a bit off. It should change smoothly with the sweep of the float arm.

 

[Mech Addict]

I was close. The range is 3 ohm to 110 ohm. The key is that it varies smoothly between them as the arm is swept through its range. It’s essentially a winding of wire with a needle that drags across the windings. Eventually many windings become one continuous slab, and have only one single resistance.

 

[t0ny]

Alas time flies. I finally took the tank to a local shop. It needs to be sandblasted and patched in a few places, resealed and it should be good to go for about $600. We were able to get some ohm readings off the sender so that was some good news. I will need to go back and sweep the arm to see how the value changes.

Unfortunately, it doesn't look like we're going to be moving much further, life got in the way and I had 3 other cars to fix. The gsx will probably be posted in the classifieds soon to see if there's any interest in the car as a whole. I'm giving my son a few days to decide what he wants to do. Time is short and he's moving away in 2 months.

Thanks for all the help and feedback.