Hello, I have inherited my late Fathers 1982 Corvette. It was found at a business in San Antonio stashed and neglected with no engine or trans. After a extensive refurb of paint, interior and engine and trans install it was back on the road again. Dad drove it on occasion it never seamed to run like it should and health issues came along. The Vette was stored in his garage then. Upon his passing it was given to me. I put a new battery in her and dropped the tank and got rid of the old fuel that was still in it. The engine and trans combo is a 1995 LT1 and 350th. I put in 10 gal. of non ethanol 92 octane and attempted to start her up. She turned over and and eventully sputtered just alittle but never came to life. I had fire to plugs but suspect the fuel was not there. I put a pressure guage on the rail and did not get any reading. I then diconnected the fuel line to the regulator and turned the key on and a slow stearm of fuel came out and was caught by a container I put there. I think it should have 35 to 45 psi of fuel at least. I put a new pump in that is for a 1995 LT1 and I have no pressure and do not hear the prime or pump run. Went home scraching my brain and researched some more. Going back today to check fuel sending power and wiring, also to check oil pressure sender connector wiring and also see if I can find a fuel pump relay somewhere on the car. Wish me luck, thanks for your time, Craig.

 

first just hot wire the pump with pressure gauge hooked up and everything off. it may have even still been the 11-12 lb pump the crossfire lived with. but now that it is something else, it will all have to be figured out-fabbed. that optispark? worst ignition setup and worse yet location anybody could dream up. 3rdgen may have more information than us as it is a camaro setup basically. welcome aboard. one guy here has an LT1 in his 75. there is a lot of info in his thread. here it is... https://www.corvetteforum.com/forums...en-2-swap.html

 

I bet it is one beautiful car with a bad-*** engine.

You might do better posting this question in the C4 Tech section since those guys deal with these motors (and Optisparks) all the time.

Some pics would be nice.

 

The earlier LT1's are Totally different than the later 1992-1996 LT-1's. The later LT1's need a specific fuel pressure to be able to run. You can't look at fuel flow and determine the fuel pressure. You have to get a fuel pressure gauge and connect it to the fuel rails or wherever the newer LT1's measure their pressure at. Having the right fuel pressure (~43 psi) is CRITICAL to the car being able to run properly. On the C4's they use a fusible link that supplies the power to the fuse that supplies power to the fuel pump. The fusible link gets it's power from the battery positive side and then goes to the fuse block. I would start by checking the electrical connections and ensure they are clean starting at the battery.

If I were in your shoes I would remove the connector to the fuel pump and apply 12 volts to the fuel pump to see it work and make pressure. On my 1988 the fuel pump assembly has three wires going to the fuel pump. One is red and a bit larger in diameter the middle one is purple and is the signal coming from the fuel level sender and the remaining wire is brown or black and is the ground. Check with a multi-meter to ensure the ground is there and giving you a solid signal. When the key is first turned on the fuel pump will run for a few seconds and stop as it just primes the fuel lines with pressure so if it stops in a couple seconds that is why. If you hold the key to crank the battery power should be at the fuel pump's red wire as long as the fuel pump is grounded. I use a device called a Power Probe which allows me to put battery voltage at the tip when I push the rocker switch forward. Be careful applying power to the fuel pump if the tank is open and fumes are around. This test of putting 12 volts to the fuel pump with the ground attached to ground should make the fuel pump run if it can.
This is where you NEED a fuel pressure gauge to ensure it is making the right fuel pressure(~43 psi) needed for the newer LT1's. If the pump works there then go to the next step and see if the Fuel Pump Relay is working and power is getting through it. If there is no power getting through your relay then you need to trace it and find the open circuit. Your Corvette should supply the power to the fuel pump through a relay and that should get gas to the front of the car. Up front there will be a fuel pressure regulator that is also very important. The Fuel pressure regulator has a diaphragm that goes bad and they do have a bad habit of failing due to Ethanol being left in them. I would also look around to be sure that the fuel in not leaking out anywhere.
On my 1988 C4 the fuel was being pumped but nothing made it to the front of the Corvette as the fuel line had corroded shut internally. This is becoming more common as the ethanol absorbs moisture and then it sits and rusts. My fuel line appeared perfect but nothing would get through it. One good way is to open the fuel filter and check that fuel is flowing through it. My blockage was at the lowest point in the fuel line which was under the passengers seat in 1988. The fuel lines were attached to the right frame rail and underneath the car.

As mentioned by derekderek whom so eloquently put it the Opti Ignition was a piece of junk from the get go. They are notorious for failing at any time when they are installed in the car. You need a scanner to watch the Opti at work to be sure everything is working as it should be. The biggest part of the problems with Opti ignition systems is the simple fact that they have not made any replacement parts that are worth a damn. To be sure that you have a spark I would suggest that you test the end of each spark plug wire by using a timing light to be absolutely sure that it is firing on all eight cylinders. Just move the probe that goes on the #1 cylinder when setting the timing to each cylinder and watch to see if the timing light flashes as that would suggest that the spark is actually happening there.

The Opti ignition is located in the worst place they could think of and is frequently known for getting moisture inside them and corroding up internally. The system uses a disc that rotates and the light is supposed to shine through the tiny holes which then triggers the spark to happen. The part that is supposed to see the light signal is the one part that goes bad very often and since nobody makes new ones the re-builders seem to favor the Mitsubishi sensors when rebuilding the Opti units. To remove the Opti ignition system to work on it requires a lot of work as you need to remove the water pump. The later Opti units had vent holes on them with a tube connected. If you see any coolant or oil around the opti then there might be problems associated with the Opti system.

Parts for the Opti are few and far apart and getting more expensive by the day. For your sake I hope that the Opti still works in your new to you Corvette. If not get a GM shop manual otherwise referred to as a Factory Service Manual and use it for troubleshooting the systems. It is critical that you use the GM FSM and not another brand as the GM is the most accurate and has the best troubleshooting charts and solutions. It is also critical that you get the FSM for the specific year of the engine used in your Corvette. You can buy the hard copies for about $90 or you can go to RockAuto and buy a DVD copy for about $35. Either one will work but you will have to have one to be able to properly take care of the Corvette with the LT1 engine.

Whomever chose the LT1 engine for the 1982 Corvette must have "thought" it was an improvement over the original Crossfire engine it came with. I would not have ever considered the LT1 engine unless it was from the early 1970 models. You might want to consider getting the LT1 that is in there out of the car and replace it with a crossfire and make the car more original. There are people who are not crazy about the crossfire but they do work and more reliably than the Later LT1's. I live in Virginia and for a 1982 Corvette used on the highways would have to have a 1982 or newer engine with properly operating Emissions equipment on it including the catalytic converters. There are plenty of very happy Crossfire people on the C4 part of the Corvette Forum. There are folks with 12 second Corvettes using the crossfire engine so it is possible to make a nice Corvette out of the Crossfire engine.

Get yourself the FSM and go ahead and try to get the LT1 to work and if you can good for you. If you have any major problems with the Opti then your choices are limited and it will cost you a bunch of money. Once the car gets fuel pressure to the injectors then you will be able to tell if the ignition is working or not. If the engine will not run or start with good solid fuel pressure then you need to start looking closer to your Opti unit. A lot of times the problems are caused by bad electrical connections so be sure that every connection is clean and free of corrosion.

If you want to learn more about the newer LT1's I would go to the C4 section of this forum and start reading and learning. There are lots of guys with years of LT1 experience who can help you a bit more than C3 owners. The newer LT1's were used in a variety of GM cars but the re-builders have been buying them up as fast as they can to get parts to rebuild the units on the roads. I hope that I have helped point you in a direction to find the problem in your 1982 Corvette. I am sorry for the loss of your father and I would like to see your experience be a good one with your Corvette. They can be awesome cars when they work properly!

Best regards,
Chris

 

Pictures! We need pictures!!!

 

Thanks derek, Harness connector going to tank I found that the fuel pump power feed was dead, no 12 volts to it. The other power lead for the gauge is operational and fine. Trying to back track power wire but disappears thru left 1/4 panel. I will take your idea and feed the pump 12V and see if that makes it come alive. Yep I know all about that opticrap piece. Might look into the alternative ignition they have out, the name escapes at this time, but they have separate coils for each cyl.

 

Thanks, Chris, for your very informative reply. I have done some research on the Opti spark and yes, it is a poor system and unreliable. I'm old school and grew up in the early 70's on the west coast during the muscle car era. I have a carbureted 350 4 bolt main complete engine. It has stage II bow tie heads that have had additional porting done to them in and complete ignition system. I have a 700thm, 350thm and a 400tm, so just have to get to work. lol.

 

700r4. sell the other 3.

 

So I go back to the Vette yesterday to do some more diagnosing. Power probe the tank unit connector and check wiring. Ground wire fine and secure to chassis. Pink wire has low voltage power to the dash gauge and is working fine. Tan wire that feeds the Fuel Pump is dead. A white wire color was sliced in and leads along frame and up into the Left quarter panel. From what I have read it should go to the fuel pump relay. Info I searched for reads the relay is behind the battery and accessed thru a plastic panel screwed in behind the left seat. And also list it to be on the firewall. I go to tech article on 95' with the LT1 which my car has in it and it shows the pump gets its 12 volts from the oil pressure sensor mounted on the rear of the engine block. I guess I will pull battery and access door behind the seat to see if it is there. Then if not go under the hood. As mentioned I will first connect 12v to wire. I installed a 95' new pump with the correct pressure for the LT1 couple days ago so confident there would be no problem having it operate. Being 6'1" and contorting in the small confines is a work out, lol.

 

the oil pressure switch is a safety thing so if you lose oil pressure it shuts fuel pump off. but there has to be another power supply for startup as otherwise you will never get oil pressure to close the switch. i don't know it that was used on 82's or not. so most likely you will have to figure out the system that was used to power that fuel pump and adapt-fab it to be workable yet have the needed safety cutoff(s). send bucaneer a PM. he is the crossfire guy. so he will know how the 82 is-was originally wired and if it would work on later model setup.

 

Thanks Derek, will do if I am unable to locate the relay in the rear compartment or the firewall.