[Project Car] 1986 Prelude "Lucy"

I did a bit of body work. The left taillight was busted so I finally got around to swapping in the replacement that was supplied by the seller. The left front fender was rusted, so I replaced that with a spare. There's still quite a bit of work left in fixing all these small penny sized rust spots all over the body.

I pulled out the carbs and manifold and discovered that I left the original gasket on. Woops! I removed it but it took some time and a razorblade. A total pain in the ass. Instead of using a premade gasket, this time I tried RTV high temp stuff, which should work. I noticed gas goo under the carbs where the carbs attach to the manifold, so that must have been leaking too. I tightened the bolts on the carbs which I hope fixed the issue. Maybe those O-ring gaskets are just trash and I need to put RTV on that too.

I started it up again and it does run better, but still runs rough. I'm making progress, but it's slow, since all this process of tuning/troubleshooting carbs is new to me.

Haven't done anything with the carbs since my last post. It's at a state where it can run well enough to drive around the block, and that'll do for now.

The car is from Minnesota, and the previous owner said it has been driven during winter at times, so when I purchased Lucy, I expected rust. There's some rust in the undercarrage, and some rusted through metal on the rear wheelwell, which is typical. There was a hole rusted through the left fender, which I already replaced. I am most concerned about the fuel filler pipe behind the gas cover, because if that's rusted through it's going to be a lot of work to fix. All that being said, I was expecting worse, but frankly as far as the frame goes, the rust isn't bad. I've seen worse and I've owned worse.

The big problem with rust, ironically, is all the surface rust. There are small rust spots all over the body. If there were a few, it'd be easy to deal with, but there must be over a hundred of them. They vary in size from a quarter to a pin head. Some places have long scratch marks, as if someone keyed it. There are a lot of spots, mostly on the roof and trunk, where the clearcoat and paint have worn off, but haven't rusted because the primer is still intact. It surprises me that a car from Minnesota has issues with paint failure.

For the undercarrage I can spray wool wax or some other rust inhibitor to prevent it from getting worse. It's the undercarrage so it doesn't matter if it looks messy. For all the painted areas, I'll have to do more work to make it a paint-able surface. If it's surface rust, grind it out. If it's rusted through, cut it out.

I started the process of grinding out the rust spots with a dremel and grindstone. Then once its bare metal I spray some WD40 to keep it from flash rusting. (I'd rather use dry coat but stores don't carry it so whatever WD40 will work.) After all the rust it removed, I plan to apply Bondo gold body filler to areas that need it, sand the rest of the painted surfaces, and apply epoxy primer. From my research it should be OK to use epoxy primer on painted surfaces, but I don't know much about painting.

I drove the car around a bit. Speedometer stopped working. I discovered that the mechanic that swapped the engine forgot to put the pin in the speedometer cable that keeps it in place, so the cable broke and I had to replace it. I hate paying money for shoddy work.

Almost all of the surface rust on the body is removed. There are some rust spots on the door by the trim pieces, but I have to remove the trim pieces to clear the rust. It took a long time because there are so many! I've never seen paint fail this way. With a paintbrush and UPOL bonding primer I touched up every bare spot. It looks ridiculous, but that should keep it from rusting while it sits in the garage.



Obviously a full paint job is required. If I repainted it as-is that would result in noticeable dips in all the uneven spots caused by my rust removal. Stripping all the paint is an option, but that takes a lot of time. I think sanding the whole body, then repainting is the way to go. I've never repainted a car and this is an unusual circumstance so I really don't know what the best approach is. Maybe I should slap bumper stickers over every spot, then clearcoat the entire car.

I'm happy to say there are only a few spots that have rusted through. These are more of a concern because I have to cut out the part, then reconstruct the removed metal some way. The biggest area where this is the case is at the fuel filler neck. Water must have pooled behind the fuel door and caused all that rust. I'll have to cut out that rust spot, shape and attach some metal/plastic part to replace that metal, then reattach the fuel filler neck. I'm not looking forward to it, but at least I don't have to make it look pretty.

The fuel filler neck housing rusted, so that required fixing. This is tricky to fix because it must be repaired in a way where water cannot get into the trunk. Water can come at it from the outside behind the gas lid, or from the inner wheel well, so it has to be sealed from both sides. What makes it even harder is it must have all the necessary holes and structural support to hold the fuel filler neck.

I started by removing the wheel and the fuel filler neck. (Of course I plugged up the rubber fuel hoses for safety.) I started by taking a dremel and grinding away the rust. Then I took navel jelly rust dissolver and pasted it over the rusted area to remove rust from various pits and groves that are hard to access. Then I sprayed the area with a water hose to remove dust and the navel jelly and let it dry. What remained was an area that had a lot of holes, but enough structure where I could fill it in. I took a sheet of fiberglass, cut out a hole for the fuel filler, then dipped the fiberglass in resin epoxy and pasted it over the area. Did this twice, for the front and back. I don't like using resin because it's sticky and viscus like corn syrup, so it makes a mess and tends to flow down. However, from my experience it makes a strong bond and with the metal/fiberglass backing it makes a decent structure. Once the resin cured, I drilled holes for the screws that were covered up, filled in any remaining gaps with silicone gel, then reinstalled the fuel filler neck.

The filler neck is attached to resin with fiberglass and metal backing. It's a bit risky to do this because the filler neck could cause the resin to stress and break, so I'm hoping there is enough metal to provide structural support. If this repair fails I'll have to do it again with a metal plate. As for it being watertight, I expect I'll have to go through one or more iterations of spraying water on it, then touching up with more silicone gel, to get at any remaining gaps.

Pulled out the fuel mixture screws to inspect them and found two are broken on one of the carbs. The part thats broken off is stuck in the idling feed holes. I tried to tap out the stuck broken needle in the hole and it won't come out. I'll have to either drill out the hole or buy a new carb.

I tried tapping it out the broken idle mixture needle but it was stuck in there good. Tried drilling it out but I was just slightly off on the angle and ended up putting in a hole where one shouldnt be. So that turned out to be a $500 lesson in just how gentle my touch has to be with those screws.

I put the new carb on, replaced the idle mixture screws on the other carb, re-seated the old carb, then tried tuning it. Balanced the carbs, but it still ran rough. I determined that cyl 2 wasnt contributing. I determined that by pulling each spark plug wire at the distributor cap individually and listening to the idle. (If the idle gets worse when the spark plug wire is pulled, that means that cylinder is contributing. If the idle stays the same, the cylinder isn't contributing.) I removed the progression hole inspection cover for that cyl and didn't see any fuel so figured it was a vacuum leak. Removed and re-seated the carb on the manifold and idle was still rough, but this time on cyl 1. This started a process of just reseating and fiddling with the carb to get the engine to fire on all cylinders. Eventually I repeatedly blipped the throttle and after I did that it idled OK. I captured the event on my gopro. I have no idea why that worked.

It still isn't running right. If I slowly open the throttle a bit it'll start backfiring out the carbs and running worse, so something weird is going on with the progression phase. You can see/hear that in the video too.

At this point I've tuned it as well as I can with the janky linkage setup. The throttle doesn't reliably spring all the way back so I had to add a spring to pull it back. The rod itself bends slightly when the throttle cable pulls at it. The cable itself is mounted with a zip tie and moves when pulled. Fixing it might require buying a new linkage setup.

The car is drive-able now! I'm quite glad I made this milestone. All that money and effort has finally lead to a running driving Prelude. It sounds great too!

I finally tackled the lingering problem of the disconnected temperature sensor. As I may have mentioned many posts ago, the temperature sensor that connects to the instrument cluster that tells you the coolant temperature is plugged into the stock manifold, which I of course replaced, so I had to figure out where else to plug it in. I was thinking of so many ways it could be done. Maybe I could 3d print a plastic housing. Maybe I could get a 1liter aluminum tank and tap in some threads. The solution ended up being way easier: just replace the vacuum temperature sensor in the thermostat housing. It wasn't being used anyway. All I needed was an adapter. Now my temperature gauge works again. In fact, it's more accurate now that it's attached to the thermostat housing instead of the manifold.

The solution for the throttle cable wasn't so easy. There's about an inch clearance between the hood and the top of the carburetor so any linkage would have to either mount to the bottom or be low profile enough to fit. There are throttle cable mounts that attach to the bottom that I considered but I'd have to get another throttle cable to go with it and do other extra work anyway. I ended up cobbling together a solution using a couple brackets and bolts from the hardware store. To make things fit I had to do some drilling and cutting. It just barely fits. If the mount was only a cm forward it would bump into the hood. Nevertheless it does fit and does hold the cable.