Wow... what a crazy week! Got back on Saturday afternoon from the honeymoon. Went straight to work installing the correct heater core and fixing a few other things.

I found what the short was, although it doesn't show up on the schematic. On the 1974, there are 5 wires that go to that switch. Two purple, one green, and two pink. One pink was marked with a white strip. I believe it's part of the fasten seat belt safety system. Disconnecting the green and pink connector didn't fix it, which was what really had me stumped. It's a direct short to ground for me.

My dad said the P.O. disconnected all of the fasten seat belt system in the car. My guess is that it broke and they disabled it by removing all of the switches. In time I'll figure it out. I still need to remove the driver's side dash to run new speaker wires and install the new speaker, clean and tighten the headlight switch, fix the air vent, and inspect the wiring for rat presents.

Good news for the weekend:

• Reverse lights worked for the first time in 30 years.
• Heater core installed and doesn't leak.
• New heater hose.
• Repaired passenger side air vent.
• Vacuumed years of dirt and debris from the rear hatches.
• Fixed oil pressure switch.
• Repaired front calipers installed.
• Found a potential short wrapped around the shifter cable. (My first thought was that was the short)
• Fresh antifreeze. Prestone 50/50 because it's properly mixed and they probably use diluted water.

Bad news:

• I learned more of the history of the car. Apparently my dad didn't take good care of the car before he built the garage. It sat outside for a while with it's leaky T-Tops and rear window where the car would fill and sit with water after it rained. This explains so much of the rust issues the car has on the inside. The rear window and new weather stripping is high on the list of repairs to do to the car. Rear window should be cheap I think. Weather stripping should be the same.
• More electrical stuff. I keep finding loose connectors around the car with nothing for them to go to. I also keep seeing 'repairs' my dad has done over the years. There is a red wire run from the starter solenoid through the firewall because the ignition wire wasn't working right. He didn't route the wire very well and it just goes up and over the exhaust headers and looks like doodoo. Wire caps? Aren't those supposed to be for home wiring? I don't even know what they went to. Corroded wires around the wiper motor. Wiper motor works, but the washer has never worked. Maybe a correlation?
• Speedometer cable is broken in two places... I can only hope it's an easy repair once I remove the dash. It's got a bad right angle coming out of the transmission. I know there is a right angled adapter for the tach cable coming out of the distributor, but I haven't heard of one for the speedometer.
• It's hotter than hell in South Mississippi. It makes working on the car miserable.

One of the best things I love about the car is the engine. 39 years old, never rebuilt, in need of a tune up (plugs, points, probably a carb cleaning), but fires right up and doesn't smoke a bit. Sounds damn good too! I can't wait to actually drive the car.

Overall a good weekend of repairs for the 'easy' stuff. Still waiting on my mechanic to get a day free to fix the transmission and rear differential seals. Definitely looks like a money pit of a car. But I know this already. I ordered the books and they should get here later this week. Maybe I can answer some of my own questions.

 

You have a new wife and a new Corvette, your living the dream!

Extra wire at the NSS:
In 74 you had to buckle up before the car would start, that was a real bummer so many people disconnected or bypassed that system. There's several parts to that system.



and here's the schematic for that:


The rear glass weatherstrip is an easy repair. Remove the interior trim and glass. Clean well, apply new sealer tape and reinstall.

The 74 service manual and aim will come in handy.

 

Long time update... been really busy moving to a new house and fixing the car...

To follow up on my last post, I ended up removing the wire that was shorting from the switch. I haven't investigated why it was shorting, but I do know the P.O. removed the seat belt system, and by the looks of it, he had no idea what he was doing.

I've been doing a lot of work under the hood and under the car. My dad and I swapped out the rear seal of the transmission and the front seal of the differential. Now the diff no longer leaks and the transmission leaked less.

Then my dad changed the transmission seal and filter. That further reduced the leaking, but it still has a slight leak. Right now I cannot afford to drop the transmission to get a little leak fixed, so I'm hoping some Lucas transmission fix will swell the gasket to keep it from leaking anymore.

Today I changed all of the belts. The power steering belt I installed before was too short and was causing the alternator belt to rub on it. Also, I couldn't remove the PS cap to refill it. Also, the PS is now leaking. There are some rough looking hoses, so that's the first thing I'll check with it.

I also swapped out the master cylinder for a brand new one. I believe I mentioned that I purchased one, but I just now installed it. Wasn't bad. The old fluid was unbelievably dirty. I purged the system by just leaving the bleeder valves cracked and slowly pumped the brakes until the fluid turned clear. Not sure what everyone uses, but I ended up putting in Valvoline DOT3/4 fluid as that's what I had put in my daily driver a while back and still had a ton left.

I also just swapped out all of the old plugs. They were Autolites, and I put in AC Delco copper ones. I also just purchased new coil and point conversion kit. I saw a few people really like the Pertronix system, so I got the Ignitor III and their Flamethrower III coil to match it. New AC Delco cap, rotor, and vacuum advance as well. Vacuum advance piston doesn't work at all and just leaks.

The car has/had NAPA Belden plug wires, but over the years, one broke and my dad replaced just that one, and then there are a few in need of repair. They have a lifetime warranty from June 1989 (older than me!), so I tried my luck at NAPA, but it doesn't look like they're going to honor the warranty without a readable receipt.... which is bull crap IMO. I have the warranty card with all of the information on it, so that should be enough.

I also neatened up all of the electrical that has fallen apart over the years. The starter solenoid wiring was a mess and just hanging over the exhaust headers. I found the clips they go in and mounted them in. I also have a temporary solution for the plug wires until I get the shields. Just using some tie-wire and heat shrink tubing to hold them off of the headers. Seems to work pretty well so far.

Also I got the headlights working great. The vacuum relays leaked really bad. I tried soaking them in brake fluid and massaging the gaskets, but they were done for. $60 and I got some new ones that work better than ever.

The horn still has me stumped. There is a break in the wire between the button and the relay. I have about 6 things planned when I remove the steering column... eventually I'll do it.

I do have a few questions.

The Stingray emblems on both sides of the car came lose. One I lost on the road on my first drive, and the other my pants snagged on and ripped it off. My dad had a spare emblem, but it was used. Is there a place I can purchase pre-cut adhesive tape for them?

The steering box is worn out I believe. I read up on how to adjust it to take out some slack. I loosened the nut while holding the bolt in place, then barely turned the bolt and then tightened the nut again. It wasn't much better, so I tried it again, but apparently that was it. It's maxed out. What's the recommendation? New or rebuild?

Also the radiator is starting to leak. As far as I know, it's the original, which means I should just get a new one because this one is likely getting rotten. The aluminum ones look nice, but they're pricey. Wilcox has the best price I've seen on them. Mid and CC are about $100 more. Or... I can get one from RockAuto or similar for around $250, but they're not aluminum. Any suggestions?

Sorry for the long post. It was a BIG update.

Thanks,
Ryan

 

There are 4 core aluminium rads on eBay new for under $200.00 from a variety of places. Some have welded billet filler and tank if I remember correctly and the built in trans coolers.

 

Yep... well I'm definitely losing coolant now. I ordered a Champion Cooling aluminum radiator from eBay. Saw a few good reviews on this forum of them and I don't have the money for a $500 one. If it will last 5 - 10 years, then I'm happy. Supposedly it has a lifetime warranty, billet filler and trans cooler built in.

For the past few days I haven't been able to get the car to run consistently. Friday night I tried to take my wife for a drive but the car was struggling to idle properly and missing really bad. Went out the next morning and started up and ran just fine. Went for a drive and came back and then it was idling about twice as high. I checked to see if the throttle cable was stuck, but the throttle plate was sitting flush on the idle set screw, so it was really just idling higher than before. Lowered the throttle down to prevent my transmission from clunking so bad when shifting. Later started it up and it was idling too low. Idled it back up and haven't touched it since. I thought it might have been the Seafoam I ran through the tank. Missing came from Seafoam dislodging some funk and clogging the jets, then idling high because the blockage cleared and it had better fuel flow, but when it idled too low again, I got really stumped.

I replaced the plug wires with Duralast ones... lifetime warranty and price point seemed good. I 'broke down' shortly after replacing them and found the plug wire from the coil to the distributor came off. Thankfully, that was it. Popped the hood, found it, plugged it back in, started it up, and took off again. I don't think I had it plugged in all the way.

 

make sure to post how it fits, maybe post a link

 

It's been a while since I posted. College and life has been hectic.

The radiator fit length and width wise, but it was much thinner than the old one. Cooling hasn't been an issue at all. In fact, I had to replace the thermostat a few weeks back because the engine wasn't warming up enough. Also replaced hoses.

Other things that have been going on...

Instrumentation
Drivetrain:
Fuel & Carburator:
Ignition: Transmission:Other:Also on order is a new gasket for the air filter housing, strut rod bushings for the rear (to remove camber), seatbelts, and heater hose.

When fixing the transmission, I also asked to get the rear-main seal in the engine replaced because it was leaking. Turns out, the entire engine is leaking. All the seals are bad. Along with a valve partially sticking open, I believe it's time to rebuild the 116k mile original engine. Being a college student, many of my young friends are saying to just stick an LS1 in there and be done with it. I believe that will ruin the appeal and value of the car. Currently it does have a numbers-matching L82 in it, which is a pretty rare engine for that year. Any recommendations?

 

ryann,

It's good to see such a young bloke getting involved in such an "old" car. You mentioned that the steering box was bad, many are. You said that the hoses were leaking too. I would recommend that you look at the Borgeson integral power steering box #800108 at www.borgeson.com. This is a late model steering box that is remanufactured to fit our C2 and C3s. It has the control valve and power ram built into it and only needs two hoses to connect it to the factory pump.

I have one in my 1974 L48 coupe and it now steers like a new car. I know that this takes away the "originality" of the car a little, but when you pop the hood, only a Corvette pedant would be able to tell that the box was not factory installed. The steering effort is reduced to less than three turns LTL and the boost is linear, the more you turn the wheel, the more boost you get. It makes driving an old Corvette pleasant.

As well, if you had to repair, rebuild or replace ALL of the main components in your steering system, you would likely spend way more doing that than buying a Borgeson box.

Regards from Down Under.

aussiejohn

 

So this week I looked into the steering issue some more while replacing the known old and cracking hoses.

Most of my play is in the control valve. I'm reading up on it right now, and there is apparently an adjustment nut, which I remember seeing, facing the passenger side of the car.

I greased up all of the joints where I could find a grease fitting. Just greasing the control valve seemed to help quite a bit.

While I was down there, I discovered that the ball joint for the drivers side steering linkage is bad. It has a ton of play in it. I'm going to get this fixed ASAP before it breaks and I crash. I also found that the passenger side wheel bearing is going out. There is a lot of play when moving the wheel around that isn't showing up on the rest of the assembly.

I also did a lot of other work this week. I recently had to replace heater hose and fuel line... well I didn't anticipate changing them when I did, so I had to make due with what the auto parts stores had. I ordered the correct hoses and installed this this weekend. I also pulled the plugs and cleaned them because of hesitation issues and did a compression check.

Keep in mind this is an L82. I'm not sure what other engine compression ratios are, but for mine, I think I should be seeing about 150PSI in each cylinder:

Cylinder:

1. 162 PSI
2. 156 PSI
3. 170 PSI
4. 153 PSI
5. 173 PSI
6. 160 PSI
7. 140 PSI
8. 165 PSI

So, with this information, this tells me this engine probably still has plenty of life in her. Why is the pressure so high though? She does need a good tune up (valve adjustment, new exhaust manifolds).

My concern now is that I often have a bad, intermittent issue with hesitation starting up from a complete stop. It is sometimes bad enough to cause what I think is a backfire. I'm not convinced it's a backfire because usually a backfire is really loud. This is more like the engine is sneezing loudly. Maybe that's because of the air filter and everything attached, unlike an old Briggs & Stratton that backfired since it was new.

Another issue is that the engine doesn't always idle up at start. I know this is controlled by the vacuum advance solenoid, which is then controlled by a number of things in the car. It's controlled by a time-delay relay as well as the TCP system. I did find some information on how TCS works in the 1974 Corvette. Surprising, I found this on Autozone.com:
This makes me believe that my temperature switch is 1) Broken, 2) Has bad wiring.

I also have an intermittent issue with the kickdown solenoid. I believe it is the actual kickdown solenoid and not wiring, but I haven't completely verified that it is not wiring. All I have done is replaced the old weathered connector on the transmission itself. I have also verified that the switch is working. I had to remove it a few weeks ago and rebuild it.