Proud New Owner-1992 NSX

[gears&tears]

Hello everyone!

I am the proud new owner of a 1992 Berlina NSX, with 100,900 miles. I purchased it from a gentleman (a retired mechanic) who owned and worked on the car himself for about a decade. I could tell he was meticulous about certain things. https://photos.app.goo.gl/NEhVDAo7e7kXYVAYA

Pros:
-it had full service done at 100k
-timing belt/service recently completed
-new brake rotors and master cylinder
-water pump, new A/C compressor
-new starter, injectors, fuel pump, coils, plugs, and O2 sensors
-Comptech headers and exhaust
-new(ish) paint
-car drives well, feels solid, motor feels healthy, and hits those nostalgic notes

Cons:
-the car was declared salvage, and later given rebuilt title from CA (2004). From my understanding, they are one of a few states that requires an inspection to get rebuilt title
-radio doesn't work. Has power, but no sound.
-small tear in drivers side seat

My buddy and I took a look at the car on a lift, and we didn't see anything glaring, but a light residue of oil under what I assumed to be the oil pan. No evidence of frame damage or repair. No evidence of damage to suspension as far as I could tell.

I plan on having the trans, clutch, and coolant fluids replaced, as I want to make sure it's done. All coolant lines, and other rubber hoses have been replaced.

I did a fair amount of research, on this forum and other resources, before purchasing this car, and am curious about a few things.

1) the snap ring was never adressed as far as he knows, but the way he put it was, "if it hasn't caused an issue by now, it's probably not going to." I read that only certain transmission codes were affected. So, would it be safe to assume that I won't have to worry about this?

2) is there a trick to turn the TCS off? I pushed the button (while driving and still) but no light went on indicating the system was off

3) I've read capacitors/relays frequently go bad. Are there any parts that would be recommended to pre-emptively change out?

4) is there a way to change the clutch engagement point, which seems to be fairly high?

My plan is to get the Quaife steering rack, new wheels and tires, carbon fiber trim to replace all the worn pieces, and upgrade the steering wheel, radio, and shifter knob. I will likely upgrade to new ABS system. Ultimately, I have plans to twin turbo car through SOS, because why not. I see it as a weekend/track car. For that reason, I won't touch the gearing ratios.

Any and all suggestions/advice are welcome! I look forward to being a member of NSXCA, and participating in regional and national events. I'm grateful and elated to be a part of this passionate community of enthusiasts.

https://photos.app.goo.gl/NEhVDAo7e7kXYVAYA

 

[gears&tears]

Also, If you live in southern Florida area, I would love to meet up!

 

[Honcho]

Welcome to NSX Prime! Congrats on the 91, you've joined one of the best car communities in the world.

A salvage NSX is always a bit of a gamble, but since it's a CA title, I feel a little better about it. If the rebuilder must certify to the state, there likely is a record of who did the work. Contrary to popular opinion, these cars can be fully rebuilt to OEM standards without compromising safety, if the work is done properly. You may want to do some sleuthing and see if you can figure out who the shop was and call them.

In the meantime, one thing you can do for peace of mind is pull the fenders and quarter panels. They're actually quite easy to remove and you can get a good look at the unibody frame. Check the crumple zones on the front panels- they should be completely straight and evenly spaced:




Check the rear panels for bends, dents or seams on the stamped sections:




You can download the body repair manual from our library and measure a "X" on the front and rear sections of the frame using the control points from the manual. This will tell you definitively if it's bent at all. I did this on my NSX for peace of mind.

Finally, the most critical thing to look for is issues on the front frame rails and extruded side sills.



These are the things that protect your physical safety more than other sections of the car. You're looking for welded seams, excessive bondo, globs of panel adhesive where it should not be. Many disreputable (read cheap) body shops won't follow the body repair manual because it takes too long and involves complex cuts and plug welding. Instead, they cut the damaged section off the car and seam weld a new section on. I think welders call it a butt-joint. Two flat panels next to each other. The issue here is this introduces a failure point on a part that was designed to transfer load. Think of folding a piece of paper. When you pull on the two sides, where does it rip? Same concept here, except the metal buckles violently and snaps off.

Shops know this (and that they can be criminally liable for the shoddy repair if it results in death or serious injury), so they try to cover the seams with bondo, panel adhesive, and/or undercoat. This has happened to several Prime members over the years, who thought they bought a solid car and had a scary accident revealing a cut-and-paste repair. Thankfully they were all ok. But, I always recommend checking, especially for salvage cars and any NSX with a Florida title. I'm willing to bet that a lot of the "pristine" NSXs that make their way through BaT have these well-concealed issues. You can check the side sills by just getting under the car. The frame rails can be inspected by removing the wheel well covers. Given your car's prior ownership, it's likely that it is fine. Mechanics generally know to look for stuff like this.

1) the snap ring was never adressed as far as he knows, but the way he put it was, "if it hasn't caused an issue by now, it's probably not going to." I read that only certain transmission codes were affected. So, would it be safe to assume that I won't have to worry about this?
You still may because of how the cutting bit moved out of spec as the cases were cut. The bit was reset periodically, so only the first few cases on the line after that were likely 100% in spec and then started to drift out of spec again. We've recently seen a rash of snap ring failures in NSXs with more than 100k miles, which tells me they were probably the cases on the line that were closer to the reset, but not close enough in time to get a full 100% cut. There's just no way to know, since you can't measure the clearance. I changed out the case on my 5-speed for the Zero even though it had ~75k miles for peace of mind. You might be lucky and have a case that was cut right after they re-adjusted the cutting bit- if so, then it won't fail.

2) is there a trick to turn the TCS off? I pushed the button (while driving and still) but no light went on indicating the system was off
The TCS switch can actually fail and has started doing so on the older cars. The symptom is exactly as you describe: push the button and nothing happens. One thing to check before that is that the TCS unit behind the drivers seat is plugged in. If it's unplugged, you'll never get a TCS light.

3) I've read capacitors/relays frequently go bad. Are there any parts that would be recommended to pre-emptively change out?
The most critical are the gauge cluster caps. NSXs have been lost to fire as a result of this issue. Other common ones are the climate control unit and radio.

4) is there a way to change the clutch engagement point, which seems to be fairly high?
Not really. The NSX catches "high". I know it feels weird, but that's how it's supposed to be. One thing you can do is adjust clutch pedal travel to the spec listed in the service manual. It doesn't affect the engagement point much though.

 

[gears&tears]

Thanks Honcho! I'll take your advice, and take a closer look under the body panels next chance I get.

 

[jrho]

Just from my personal experience of having my snap ring range transmission fail at 138k, I would at least check the condition of the snap ring. If I remember correctly, this can be done through an inspection port to see if it's intact (not a sure fire way to tell that you don't have an issue but if it's in one piece it's a good start) while doing a transmission fluid change. Sounds like you got a great example of an NSX. I wouldn't be shy of a rebuilt title NSX as long as it's been repaired properly. It's a great way to get into one at a reduced price.

 

[gears&tears]

@Honcho : those pics are super helpful, thank you! love the build by the way. Chef's kiss.

@jrho: Yikes. that's unnerving. looked through nsxtscy85's thread, and looks pretty simple to just peek at. I'll post pics since I wont know what a good vs bad one looks like

I have driven it a bit for the past couple days (owned for less than a week, unregistered in FL at this time), and I've noticed a few things I'm hoping y'all can clarify.

Inspecting the engine bay, I found this rubber hose. Looks like it snapped off the fuel evap canister? Does it need replacement?





If anyone notices anything else amiss in the engine bay, please advise.

In an attempt to diagnose the radio malfunction, I took a look at the sub, and surrounding wiring. I believe I'm missing a trim piece or carpet, as I don't think all of this should be exposed? Also, there are blue, grey, and pink connectors loose. What are these for, and should they be plugged in somewhere?






And finally, but perhaps most pressing in southern Florida, is the weak AC. Previous owner reports the compressor was changed one year ago, and charged with 134a. The passenger side seems cold, but the drivers side, not so much. The fans seem to be working, as the air flow is strong, but maybe slightly weaker on the drivers side. Anyone have any idea how this could be? Clogged vents somehow?

Some cursory reading lead me down the path of bad receivers/driers/ expansion valves/ evaporators, but I imagine that would cause the whole cabin to be warm, and not just one side. I'm planning on flushing and recharging the system with 134a to see if that makes a difference.

As always, thanks for the help.

 

[ih8ricerz]

Congrats on your purchase!! I just picked up a 92 Berlina NSX as well... such an awesome car that makes you grin every time you accelerate!

 

[gears&tears]

Congrats on your purchase!! I just picked up a 92 Berlina NSX as well... such an awesome car that makes you grin every time you accelerate!

Couldn't agree more. Congratulations and welcome!

 

[Honcho]

Let's start with the engine bay pic



The good:

• You appear to have the Science of Speed oil pressure sensor relocation product (Number 1 above). It's a nice product.
• Your coolant overflow tank looks like the Dali Racing "jug" unit. It's very sturdy and should last a long time. Just make sure to clean and pressure test the cap to make sure it's doing its job. They can get crusty.

The not-so-good: It's evident that this engine was removed during the rebuild process and put back in in a somewhat sloppy way.

2 - This engine ground is not stock. It look like someone crimped a Home Depot terminal ring on a wire and then slipped the factory (ripped) boot over it. The factory part is:
3 - These are not the factory fuel hoses and present a fire risk. The factory hoses are quite expensive, so it seems the rebuilder wanted to cut corners here. Also, it looks like the fuel filter may be missing? The hose part numbers are: 17707-SL0-A31 and 16722-PR7-A03
4 - All of the visible coolant hoses are using a jubilee-style hose clamp. These clamps will cause serious leaks over time as they crush the hose. The factory clamps adjust tension as the rubber expands and contracts. People have lost NSX engines due to these clamps- air gets sucked in and blows the head gasket. Unfortunately, to repair properly, you need to replace the hose along with the clamp, since the jubilee clamps damage the hose. It may be worth it to inspect all the hoses and replace any clamps that are missing. It's probably cheaper to buy a hose set from SOS and then replace as needed. You can get the clamps from Acura or JDM Honda.
5 - This is not the factory vacuum hose. It looks like it was taken from another car and patched into the intake manifold. The factory part is: 17725-SL0-A02
6 - Yes, you're correct that the purge canister has broken at the nipple for the vacuum hose. This is a critical part of the fuel system that is responsible for purging dangerous fuel vapors from the tank. It should be replaced. The part number is: 17300-SL0-A34 though it may have been superseded by a newer part. Also, if you look at the vapor hose attached to the canister (with red lettering) and follow it down, it does not connect to a factory hose. This is going to your gas tank. The part number is: 17721-SL0-A02. My NSX is in the parking garage at work right now, but on my way home, I'll snap a pic of the hoses to show you what goes where. None of these hoses are right.

Finally, that mushroom filter is terrible- you're basically sucking sand into your engine. I would try to find the OEM airbox and use the standard paper filter element.

The story I'm seeing from this picture is that the engine was very hastily and roughly removed from the chassis after the accident. Whoever the monkey was that did it probably cut all the hoses, wires and lines with a sawzall and threw the pieces away- you know, the ones that had all the factory clamps on them. Now you have to fix his crappy work lol.

Although the jubilee clamps scare me, if they aren't leaking you can get away with it for a while. Instead, I'd make task number 1 the fuel system. It's a critical safety component. You need to drop the fuel tank and inventory the non-OEM lines. Believe it or not, dropping the tank isn't that bad of a job if you drain it first. I would make sure to sort out any missing/hacked hoses and replace them with OEM. Make sure that fuel is getting from the tank to the engine using all factory fittings. Next, make sure that all of the purge canister hoses are OEM and coming off the tank to the canister. While the tank is out, it's time to consider replacing the fuel pump- they tend to get tired around 100k miles on the NSX. Rock Auto has OEM-equivalent units.

Once you get the fuel system sorted, I would move on to the coolant hoses and clamps and get those sorted. You can get the purge canister and airbox from a scrapyard or a vendor like ATR Parts. I think there may be a few airboxes for sale in the marketplace here on Prime as well.

Hope this helps.

 

[gears&tears]

Honcho, you are a saint. I feel like I should be paying for this.

With regards to the fueling system, the seller reports he just replaced the fuel pump, injectors and fuel sender. Perhaps he mistakenly replaced the OEM fuel lines, thinking that "newer was better?"

Maybe he was going for this....
https://www.nsxprime.com/threads/running-larger-fuel-lines.162261/post-1590566

I guess my humble question, before I buy the OEM parts, would there be a problem with running high-quality, braided fuel lines? Is there a way to run them safely? I plan on FI in the future, would that be a consideration? Reading the aforementioned thread, a few people have had no issues in high-power applications. Forgive my ignorance if I'm way off.

In any case, I went ahead and purchased a new evap cannister (#6) and OEM hoses that go with it (#5 in your lovely diagram). Would you happen to know if the clamps I need are 91406-SL0-931 or 95002-41050-04?

With the regards to the coolant hoses, the seller also reports very recently replacing those with silicone hoses. Does that make a difference? Is this the proper clamp? 19513-PE0-003

I'm quite embarrassed to admit that I drove the car before noticing the air filter myself. I took the path of least resistance, and ordered a replacement HKS filter. Really hoping I didn't eff anything up.

Here's another pic of the engine bay. I found some janky aftermarket engine bay light set-up....unless that's factory??
See green wire at the back of the bay. If there's anything else I should consider, might as well rip off the whole Band-Aid.

 

[Honcho]

Grabbed a pic when I got home.



There are three hoses on the purge canister. The hose with the number 6/9 (depending on how you view it lol) is the vacuum control line that goes to the purge solenoid in the vacuum control box. It is actually two rubber pieces connected by a hard plastic shaped line that clips into the factory airbox. You can see a little bit of the plastic in the picture. This is the vacuum control line (95005-35008, 3.5mm) that opens and closes the purge valve on top of the canister. I can't seem to find the part number for the plastic section. The hose with the regular OEM hose clamp (95002-41050-04, 10.5mm) is the vapor purge line that connects to the nipple on the throttle body (17725-SL0-A02). This hose also clips into the factory airbox (there are yellowish-white marks on the hose, you can see one in the pic) and provides a path for fuel vapor to be drawn back into the engine to be burned. The last hose with the little wire clamp (95002-02104) is a fuel-grade rubber line that connects to the 2-way valve on the gas tank. This draws vapor up from the tank into the canister. Honda doesn't sell the hose section anymore, so you have to buy a bulk roll of hose (95001-55008) .Sometimes a cool Honda service department guy will let you buy a shorter length. I bought a 10m roll since I replaced all of the hoses on the gas tank and most of them are this size. There is one more hose you can't see- the fresh air draw hose on the bottom of the canister. Honda calls it a "drain" but it actually connects to a 1-way valve (like the PCV valve) at the bottom of the car to draw fresh air into the canister when it purges vapor. The new hose is pink. Again, you have to buy a roll of it (95003-40003), but the OEM cut length is 380mm. To "complete" the assembly, you'll need the little back hose bracket that pushes into the metal bracket holding the fuse box (91592-SL0-003). This should get your fuel vapor purge system fully sorted.



I guess my humble question, before I buy the OEM parts, would there be a problem with running high-quality, braided fuel lines? Is there a way to run them safely? I plan on FI in the future, would that be a consideration? Reading the aforementioned thread, a few people have had no issues in high-power applications. Forgive my ignorance if I'm way off.
Generally, a high-quality AN fitting using professionally crimped hose ends can work with a good braided ethanol-rated fuel hose. One of the issues with braided lines is that grit and silica can work its way into the mesh and rub away at the interior rubber as the mesh flexes. However, that takes a long time. The down side is you can't really see the wear. I personally was not willing to take the risk when dealing with gasoline. In my case, I replaced the rubber sections with Parker Wavemaster Marine fuel hose and had them professionally crimped like OEM.


I wasn't willing to gamble with braided lines and AN fittings, but that's just me. Plenty of cars use them just fine. The key is to find a good fabricator who uses quality materials and take the time to lay out the hose shape so that they fit well and don't rub on anything. FWIW, it's probably cheaper to just buy new OEM lines and they will last 20 years. They will flow plenty of fuel to supply the supercharger. From what I can see in your picture, they used a hose clamp to put the blue fitting on the fuel hose. These should be ferrule crimped like in the above pic for safety.

In any case, I went ahead and purchased a new evap cannister (#6) and OEM hoses that go with it (#5 in your lovely diagram). Would you happen to know if the clamps I need are 91406-SL0-931 or 95002-41050-04?
95002-41050-04

With the regards to the coolant hoses, the seller also reports very recently replacing those with silicone hoses. Does that make a difference? Is this the proper clamp? 19513-PE0-003
Silicone hoses are the fad in the tuner scene since they have better heat resistance than rubber and plenty of people use them. However, I was advised by one of the NSX engineers to stick with the OEM rubber and have followed that advice. I've never seen silicone fail though. You should still use OEM clamps with the silicone hoses and if they have been crushed by the jubilee clips, replace them.

I'm quite embarrassed to admit that I drove the car before noticing the air filter myself. I took the path of least resistance, and ordered a replacement HKS filter. Really hoping I didn't eff anything up.
Don't worry about it. It's not like using that filter will make your engine explode. The issue is the fine silica dust will over time cause wear on your main bearings and degrade your ring seals.

A few other things I noticed in the engine bay is that there's something going on with your fuel pump resistor(16717-PR7-A01. It looks like it has some blue and red Home Depot crimp connectors on it. and the other side doesn't look like the factory harness. Maybe he jumped the resistor to force the pump into high mode all the time? Also, you appear to be missing the fuel return hard line (17740-SL0-030 and 37867-RH2-E00, clamps are 91406-SL0-931). It's the line that goes from the pressure regulator back into the gas tank. They used a steel braided hose instead and it looks like it's just flopping around in there. Given the bodgy state of the fuel system, I'd pull the injector coves and see what he "replaced" the injectors with, making sure there are no gas leaks at the fuel rail.