I have recently picked up a 100 percent original 1981 Corvette, 46,000 miles, all original paint, interior, computer system etc. It is probably the most original car I have ever owned, even down to original spark plugs and wires etc. So the question is, should I stick with the original computerized carb and dizzy (which will cost around 300+ to restore or more if I need to replace sensors) Or just ditch it and install a regular carb and dizzy? Vote in the poll and tell me what you think.

 

I think the value is always enhanced keeping it original. Unless you plan on major performance modifications for competition That's what I would do.

 

So why monkey with it?

 

If you replace the original equipment, just keep it stored away so you have the option of reinstalling it later.

DC

 

If it's in good shape I would keep it original and tune it with the correct parts.

 

the computer in my '81 work flawlessly. it starts up every time with no issues, idles great, runs great, good fuel mileage for no overdrive. (16-18mpg).

Why take it out? it might cost you $300 if you have to replace EVERY sensor and the ECM at the same time. otherwise, parts are cheap, and rarely go bad. and you can still modify for more HP with the stock setup

 

The problem is that trouble shooting electronics is not my strongpoint. In this car, I have no idea if the ECM is any good or if it is even getting power. The check engine light does not come on at all, the smog pump is missing and Im sure I would have to buy all new sensors and even some wiring. Ill have to think on it a little

 

Ben what s the overall condition of all the components and the car? Awards like the NCRS Bowtie and Bloomington Gold Survivor come to mind when someone speaks of such originality. Would you be interested in attempting to work towards such an award?

What are your goals for the car?

 

I removed all the smog stuff on my 81. have true dualls, set timing to 12 degrees, had the elec quad carb worked over and still have the computer. runs flawlessly. its no beast but better than factory. next step is cam ,heads and better headers and plan on keeping comp.

 

The car is super original, but I dont think that it would qualify for any of those type of awards. I mean the paint yes is original, but the paint on the bumpers is all faded and not glossy like the rest of the factory paint. The interior is all original, but I will have to replace the carpet seeing it did not come with any. Everything under the hood is factory. I guess I am not really versed much un the NCRS type stuff. I wonder when people are looking for C3s if they are looking for more original cars or not. I personally LOVE original cars, because honestly that is a look tha is hard to mess up. I mean all mods and customization are in the eyes of the beholder...

 

namvet6869...
Interesting. But what does that have to do with the poster's question?

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If the car is in 'original' condition and all the computerized engine hardware is there and working, why would you remove it? If you do, then you no longer have an 'original' condition vehicle. You would be better off spending less and buying one that has already been modified.

The '81 car has the OBD-I diagnostic system. If you check out the car, see if the "Check Engine" light comes on when you turn the key to "ON" position (prior to starting the engine). If it does, then the bulb has not burned out or been removed. Then start the engine and see if the C/E light goes out. If it does, then the computer senses that the "system" is operational. That's a good indication that the induction and ignition systems are working as expected.

If the engine starts well, idles well and operates as expected when you drive it, that would indicate that the systems are good.

If the C/E light does NOT light with ignition ON but engine not yet started, either the bulb is burned out or it has been removed so that the C/E light will not be ON when the engine is operating--not a good sign for that car.

 

the smog pump is not part of the system. you can unplug it along with the EGR and not get a Check engine light on. Mine is currently out of the car as well.

The main parts are the carb, throttle position sensor, mixture control solenoid, the distributor, the coolant temp sensor, and the o2 sensor.

if you pull the ashtray out, you'll see a connector under it. just the first two terminals with the key on and the check engine light should flash a code 12 if everything is ok.

 

that is the real reason why I asked if it makes a difference, BC on my car it seemss like the whole computer system is totally shot. Cel does not light and I get no response from the computer

 

i'd check the bulb first like 7T1 said. my bulb was burnt out when I bought my car. replaced it and everything works fine now. You'll definitely need the GM service manual for the car though.

 

It seems like you're really not sure what you may be up against. Before you do something rash let a friend who is knowledgeable about automotive electronics or a fellow Corvette guy take a look at the car. Things may not be "bad" as you think they could be.
If the car is all original don't be to quick to start modding it.

 

if its not broke , don't fix it

if you want to hot rod , why not start with a homeless non original car to monkey with and wrench on.

to me this is working backwards , why spend the money for original , if the goal is something different .

lots of lonesome project cars , needing love and Transplants of modern motors and 383 's and alike.

 

A bunch of thoughts come to mind. Here they are in no particular order.

If the smog pump is missing and you aren't too familiar with the system, what leads you to believe that it's all original? A pic from under the hood, especially the top of the carb and distributor connector plug would give us a good hint.

The CEL is the easiest way to check if the system is working properly but not the only one. If you can find a quiet area (a closed garage is good), with a cold engine, put a jumper across the two test pins (no divider between them) in the ALDL plug under your ashtray and turn the ignition to the run position without starting it. You should hear clicking noises from the carb. No clicking, something is wrong.

Another way to check if the computer is doing something is to disconnect the multi pin connector at the carb. Check the timing at idle and again as the revs increase. Now reconnect the plug and do it again. Timing should not change with RPM without the connector but should change with it.

Originality or modify is a choice that only you can make. 81's tend not to be in high demand (relative to other C3's) because they made so many of them so the increase in value for originality caries less of a premium than other years. Having said this, it's hard to register or sell it in many states (like CA) without the original equipment in place and functioning. Just by reducing the market that you might sell it to, you'll tend to get less for it.

Last thought is to not be intimidated by the electronics. The CCC is only slightly more complex than the electronics module in the pulse wiper system. The computer itself tends to either work or not work. The rest of the components in the system are not particularly hard to work with but you kind of need the computer and CEL working to start evaluating and tinkering with these.

 

I checked it before I installed the center gauges, it looked fine to me, but I will check it again.
I dont want to start modding this car, that would be the last thing to do. I already took the car to Tracdogg2 when I got it and he gave me some pointers on it. I would also consider myself a corvette guy, just not one that has ever delt with computerized 1981 systems.

Why do people think I am going to hot rod this car? My intent is nothing like this at all. And how did replacing the carb and dizzy become hotrodding???

I am considering just buying another ECM and seeing if It makes a difference. As you all, know throwing parts at the car is not the best idea, so I am hoping the forum can help.

 

Is the car currently running? I am no expert on this setup but I would keep it stock if I could. I have a good source for hard to find parts. UPEX Auto Supply Dallas, TX. Ask for John. Tell him you know mike. mike...

 

Mike, what kind of parts do they have? Also, I think my 1958 Chevy is ready to see if we can get the ac to work. Any pointers?