1996 Collector Edition Corvette

[MostMint]

Here is what I would do:

Fix the fuel sending unit

You have two choices. The first is to get another one. I'm thinking this should be under $200
The second is to fix the current one. You will want to determine if the pump works. This might affect your decision. The rust you have does not look worse than what mine had so the sending unit may be salvageable.

If you choose to repair then disassemble the entire unit, dry it out and clean off the rust. Use the water pressure trick to flush out the pressure and return lines on the sending unit. You should be able to disassemble the fuel sending unit and clean the rust out of it. If you break it then you can just get a new fuel sending unit assembly. Once you clean the rust off everything you can reassemble all but the pump and check the sending unit.

After that you can try the fuel pump. Clean all the rust off it and reconnect it to the sending unit. I used zip ties around the outside to hold it in place. You'll want to hear the pump cycle when you turn the key on. If it doesn't cycle you will need a new pump. You can get the pump separate or as part of the sending unit. If it cycles you will want to flush it out too. This one I'd probably use kerosene.

At this point you will want a new fuel sock - these are cheap


Clean out the fuel lines. You will need to flush out the fuel lines. We'll take the system one line at a time
1) remove the fuel filter
2) disconnect the fuel lines from the fuel injector rail
3) disconnect both fuel lines from fuel sending unit (already done it appears)
4) for each line, I would want to get that rusty fuel/water combo out of the lines. What I did was put water into the lines, then blow it out with compressed air. There are three lines (tank to filter, filter to rail, rail to tank). Keep doing this until what comes out the other end is clean. You can use kerosene or whatever else you want, but the water will flush out all the junk and no messy cleanup.
5) after this I would get a new filter and reassemble

Clean out the fuel injector rail
1) The fuel pressure regulator may also be full of rust. I don't know where this is located on the LT4 but you will want to remove it and clean it out. If it's beyond cleaning get a replacement.
2) The same process you used to flush out the fuel lines you will want to use to flush out the fuel injector rails.
There is a distinct possibility that rust bits made it to the injectors. Depending on what comes out of the injector rails can help guide your decision. If there is just rust color liquid and no chunks it might be OK. Worst case it you get the whole system flushed and the injectors are blocked and they need to be cleaned or replaced.
3) put the pressure regulator back in

put the system back to fuel
1) reassemble all the fuel lines, but do not connect the return line to the sending unit, get a piece of hose and direct it to a bucket
2) put a gallon or two of gas in the tank
3) cycle the fuel pump until clean fuel is coming into the bucket
4) reattach the return line

The water for flushing should not do much damage, as it will only be in there a short time, as opposed to the 3-4 years this one sat with moisture in the tank, and the final assemble will flush out the last bits of moisture and any residuals missed during the flushing. The reason I cleaned out all the lines is to minimize stuff in the filter, and stuff headed to the injectors.

My best guess as to why this happens is these cars have a evap canister that allows air to come in but not go out so easily which I believe is the cause of the water getting into the tank. It's worse when they are left low on fuel.

Would be willing to talk about this so let me know if you want to call and talk it out further

[wxo]

Today I didn't accomplish very much. I disconnected the fuel lines from the fuel rail before I began to remove the rail. I spent time cleaning out the pecan shells that the squirrels left on the intake manifold.

Along the way I found a vacuum connection that has obviously been broken and leaking for a long time.

Once the fuel rail was out, I pulled an injector to see what things look like. I struck water again.

Next time I plan to try to clean out the rail and the pressure regulator and then move on to the injectors. I hope to be able to learn how to test them to determine if they are still salvageable along with the regulator.

[GMJohnny]

WXO,

Reading about the rusty fuel lines —- I’m wondering if there’s a solution you could make up with rust
remover ( CLR ?? ) in it that you could use to help expedite the process and make it so you only have to
flush them a couple of times and it will be a really thorough flush. Just a thought.

GM

[wxo]

I don't know yet how bad the fuel lines are. I haven't gotten to that point yet. I have been on the phone with Mostmint to get his advice and understand what I am up against. One of his fuel lines actually ruptured. He's been there. The CLR or equivalent is a good idea. I will seriously consider that. Thanks.

[wxo]

I'm still picking at the fuel system. I am now focused on the injectors, fuel rail, and pressure regulator. I disassembled the fuel rail assembly and saw that the water contamination was bad. Rust on the injectors leads me to believe that water has sat in this system for years. I was able to have a long phone conversation with Rich Jensen of CruzinPerformance in Michigan. He has 30 years in the injector rebuilding business. He is currently laid up after shoulder surgery and was gracious enough to agree to a phone call on Sunday. Rich took on any and all of my questions about fuel injectors and related questions. I asked him why the part number on my injectors doesn't match the information I found on the web. To answer the question he went out to his garage and looked at one of the two LT4 crate engines he bought back in the 90's to verify that my part number is the same on his engines. You can't get better verification than that.

Bottom line he stated that water is the enemy of injectors and attempting to rebuild mine would probably be futile. OEM injectors for this LT4 are hard to find and expensive. Rich said that injector technology has greatly improved since the 90's and I'd be better off with something newer. I'm looking at ACCEL injectors with the same specs.

The pressure regulator in the Vette is, as expected, clogged with rust also. Rich suggested an adjustable one, but for now, to keep things simple, I'm going with just a replacement.

My next task in this mini fuel system project is to find new 0-rings for all these components (except the injectors). "The Beat Goes On"

[wxo]

I decided on these injectors:
https://smile.amazon.com/gp/product/B00 ... UTF8&psc=1

I was able to learn that Viton o-rings are the best choice of material for the fuel rail and related parts. It is chemical resistant and has a higher temperature range than the other choices. So a box of these babies are on the way.

Next I turned my attention back to the gas tank since the new pump hanger assembly had arrived from Amazon. The only one of these available that I could find is from Delphi which, I believe, has a very good reputation since it is a GM supplier. For some reason, I decided to look at the assembly to see if I could find out where it was made. Looking around the filler neck, I noticed this:

So I turned it over to get a look at the bottom side and saw this:

The plating was poor and serious rust had formed. I can't tell you how glad I was to have looked this over. It could have been serious trouble in the future if I had used it. Just to let Delphi know, I called their support and they were less than useless. One guy tried to say that this was a Chinese knockoff. It was made in China all right, but it was in an official nice looking Delphi box professionally packed.
So, now I'm back to searching the web again. This time I looked at RockAuto and they had the same one for a bit less, so I ordered it. I'll look it over carefully when it arrives and hope that the one I got had slipped through quality control. We will see.
Tomorrow I hope to take on the difficult task of removing the fuel filter and flushing the gas lines. I have it all jacked up and ready to go.

[Maverick]

When ordering parts the last few years, maybe 20-25% had some issue when they arrived. Don't know how the pros cope with it. Here's hoping the RockAuto part is OK. Any issue with returning the part you have?

[wxo]

No problem at all returning with Amazon. I marked it defective on the return and UPS will pick it up tomorrow.

GM Johnny suggested I use a rust remover to help clean out the fuel lines. Today I watched a Youtube video by the "Project Farm" testing rust removers. From that I ordered some Evapo-Rust. I intend to fill the lines with it and let it stand for a few hours before rinsing it away.

BTW, John, CLR turned out to be one of the most ineffective rust removers in the test.

[wxo]

This project is moving along well, but removing the fuel filter turned out to be a major project. I found out that a convertible has a major X brace across the bottom of the car which stiffens the chassis. None of the YouTube videos showing how to remove the fuel filter mention this for obvious reasons. It also turns out that this brace interferes with access to the fuel filter. So off it had to come. In fact, when I finally removed the filter and saw that it was an "AC" brand, I believe it has never been changed. Also for obvious reasons. I blew into it and could tell that there was significant resistance. The car could probably run like this, but not well.

The last thing I did today was to blow out the fuel lines and fill them with Evapo-Rust from Maverick's stash. I plugged the lower ends of the tubing and poured the rust remover in from the top with a very small funnel. I believe I succeeded in getting them nice and full.

I wonder what other surprises are in store for me.

[wxo]

Since I'm still waiting for parts for the fuel system, I decided to let the fuel lines soak for another day. So, I turned my attention to the front brakes. With the front end tilted up, I've never had such convenient access to the front suspension for brake work. This turned out to be really handy when I tried to remove the rotor. It was rusted tightly on the hub and nothing I did would make it budge, so off to the internet for some ideas. This one did the trick and rather easily: https://youtu.be/SCmOxn8k8qk . Once off, I decided to give the rotor an Evapo-Rust treatment overnight. My plan is to remove the rust so that I can get a better measurement of the thickness. I'm hoping there is enough material there to have them resurfaced. I also ordered replacement rubber brake hoses for all four wheels. I'm not sure of the condition of the caliper pistons. I believe I will just get a kit and rebuild them. They are special calipers with the word "Corvette" cast into them for the Collector Edition. Finally, my Accel injectors came today. It will be a fine day when I can put them to work.

[MostMint]

we couldn't find rear calipers so we rebuilt them on mine. It's been too long I can't recall specifics but it not too difficult

[wxo]

we couldn't find rear calipers so we rebuilt them on mine. It's been too long I can't recall specifics but it not too difficult

I've rebuilt quite a few calipers. It's not difficult.

[wxo]

I took the left front rotor out of Evapo-Rust, sprayed it with water to clean it up and measured the thickness. It was 1.075" and the minimum is 1". They are not deeply grooved, so I believe I can have them successfully resurfaced. I also removed the right front rotor today. It was not stuck on the hub like the other one. I'm planning to take them both to the machine shop tomorrow morning.

The other news is that my second fuel pump hanger assembly arrived today from Rockauto. Opening the box, I saw that it had the same rust problem! Since Rockauto has discontinued phone support, my only option was to return it, hoping for a charm on the third one. If I get a third bad one, I'm thinking about fixing the rust myself. I think I should be able to remove the rust with Evapo-Rust and then coat it with something to prevent it from coming back and also resist the gasoline environment of the filler neck. I'm open to ideas if you want to chime in.

I flushed out the gas lines nearest to the engine and followed with a blast of air. They are hanging to air dry now. I still have the lines from the tank to the gas filter soaking. I hope to get to them tomorrow.

The next thing I need to tackle is pulling the plugs and getting some penetrating oil soaking in the cylinders in preparation for startup. The Beat Goes On...and I'm enjoying the heck out of this.

[Maverick]

Haven't used this but I bet it's good. I liked all the POR products I have used.

https://por15.com/products/fuel-tank-sealer

Have you turned the engine by hand yet?

[wxo]

I will look into POR15 as a possibility. There is a spring loaded mechanism for the flap in the filler neck. I'm not sure if POR15 would work in that case.
I have not turned the engine by hand as yet.