First of all, hello everyone, I am writing from Türkiye. I have a 1972 model 454 big block c3 corvette. The engine of the vehicle is not working right now.I took the car out of the garage in the evening as a routine. After driving 1 km, the engine suddenly stopped. The fuel was a little low but not so low that it would not start. Then I thought it might be the fuel and filled it with fuel. It still did not start. I thought it might be the fuel pump fault, so I disconnected the hose going to the carburetor and started the starter, and the fuel filled the bottle very quickly. I thought it might be the spark plug and saw that I had 2-3 burnt spark plugs. I put in 8 new spark plugs and it still did not work. There is ignition in the spark plugs, the starter works but the engine does not start. I am waiting for your help, thank you in advance. Meanwhile, when I press the starter, a very loud explosion sound comes from the exhaust.

 

Hello, writing to you from Australia.
Welcome to the forum!
Loud bang from the exhaust when trying to start makes it sound like perhaps it's jumped time.
Just a guess of course.
3 things you need for your engine to run.
Compression
Spark
Fuel
Not likely you lost Compression all of a sudden and without loud noises.
You checked the fuel pump. And fuel delivery seems fine. Did you remove the airfilter lid, look inside while pumping the throttle to see if fuel is spraying? Have you tryed giving it a shot of starter fluid?
And then there's spark. You say you have spark. But has it jumped time? If the spark is at the wrong time loud banging happens but engines don't run.
Try putting a timing light on it while you crank the starter. Is the timing close? Nylon teeth on timing chain sprockets on these engines are prone to failure.

 

First of all, thank you very much for your interest. Yes, after about 4-5 seconds after starting the car, if I push it, there is a loud popping sound from the exhaust. We removed the air filter, but of course I can't say for sure whether the fuel is going in or not. We just removed the hose going to the carburetor, started it with an empty canister and filled it, and I saw that it worked without any problems. You say there may be a jumping problem. Could I encounter such a problem on its own without changing the location of the cables? Because I didn't open the hood and touch anything. By the way, yes, when the engine stopped while driving, it stopped very quietly. There was no strange noise. Other than that, I didn't try to start it with starter fluid.

 

And by the way, if I may add, the mechanic told me that the carbon in the distributor cap was finished. But the mechanics here really don't know much about American cars.

 

Welcome to the Corvette Forum Alican1903!

Your mechanic was right, that distributor cap is SHOT... With a new cap and rotor do you get a spark at the spark plugs? It sounds like an ignition issue to me from your description and after looking at your distributor cap it appears that you might want to start with a good tune up. I see the distributor has corrosion so verify the ignition points and condenser are working properly. You might try another ignition coil as they are known for failing in many different ways. I have seen a bunch of the ignition coils fail over the past couple of years. The ignition coils that sit for any time can fail as they start to warm up.

Has the car ever had any bad electrical shorts recently? Does the Horn relay have power getting to it? I ask this because there are two fusible links that protect the power getting to the fuse block. Does the fuse block have power getting to it? If not then the fusible links should be tested for conductivity. They are located near the starter motor and go up to the Horn relay on the drivers side.

I would check the ignition system carefully for any loose wires or broken connections. My C4 was intermittently cutting out while driving, I searched high and low and found nothing until I noticed the power terminal was loose and making/breaking the connection which was making the car act really strange.

Does the gasoline in Turkey have Ethanol in it for better emissions? Ethanol is like brake fluid and absorbs moisture, over time ethanol can rust shut the fuel lines internally. I had this happen on my C4 and it was hard to diagnose.

It has been many years since I have been in Turkey, I once lived in Ankara and then down in Adana for a few years. Turkey is a beautiful country and it must be fun to have a Corvette over there. I used to love going to the beaches. Once I drove from Turkey to Israel only to not be able to enter Israel. We spent two weeks at a beachfront in Lebanon while the world was in Chaos because of the Cuban Embargo. I still remember getting ice teas on the beach back then in Beirut, it was so peaceful back then. I hope to return to Turkey once again before getting too old.

 

alican,

Your mechanic has a "good eye" to catch that dist cap issue. Few people even look in there.

Not sure your parts availability in your area, but you need to order a Cap & Rotor as a set, soon.
The center terminal is shot. And likely the center of the rotor is bad also. And for what it's worth, there is a huge difference between a $19.95 set and a $50 set.

This is an easy fix. Just mark all plug wires with masking tape & a Sharpie. Swap both parts out.
Should be good to go.

There might be some electrical resistance issues going on here with your IGN system. Pretty rare for the center cap terminal to corrode that bad.
Maybe someone will chime in on some tests to perform for voltage & resistance, using an OHM meter.

 

​​​​​​​Thank you for your help and kind words about my country. I am also in Mersin, which is 70 km away from Adana. If you ever visit this region, please be my guest. Yes, it is really fun to have a vehicle like Corvette in the Mediterranean. I will test the fuse and horn issue and inform you here again. I hope I can start the vehicle as soon as possible and enjoy the trip in the Mediterranean

 

Thank you very much. I don't have any problems with Corvette spare parts here. It is difficult to find cosmetic parts, so I paid around 17,000 USD including taxes to bring Dewitts radiator, air conditioner and cosmetic products from America. But it is easy to find engine related parts. Could you please share a link for the exact same product I need?

 

I bought 8 new Acdelco brand spark plugs. When we tested the spark plugs before buying them, there was a spark, only a few were weak, so we replaced all of them with new ones.

 

Probably not related to your problem but you need to put a breather in the hole I see in your passenger side valve cover. assuming your PCV valve is hooked up on the driver side you do not want it pulling in unfiltered air into your crankcase and carb normally there is a hose assembly that goes from the valve cover to the stock air cleaner which you do not have. also, it would not hurt to remove your air cleaner assembly and take a few pictures of what you have going on with the carb and intake and someone may be able to notice if there are any hose etc. that are not hooked up correctly.
Pat

 

Thank you very much, believe me, I don't even know what the part you call pcv valve is, I just looked it up on the internet and learned it. I will take a detailed photo of the engine tomorrow. I hope I can make my vehicle better with the information you provided.

 

I would start with replacing the distributor cap, rotor and coil.
If the ignition has been changed from the original points and condenser, which it looks like it possibly was, I would check the module.
After that, if it won’t start, I would double check that you are getting fuel into the carb, by removing the air filter lid and while looking into the carb, pump the throttle.
You don’t need to do it while trying to start the car, but if you do, keep your head from being over the top of the carb just in case it backfires.
You should see fuel squirting from the squirters into the ventures.

As suggested by 4 Vettes, a backfire through the exhaust could be caused by the timing chain jumping a tooth, which would be the reason the engine just stopped running.
Don’t keep trying to start or run the engine if the timing chain has jumped, because it can cause serious damage to the engine if you run it.
The original timing gears on these cars were plastic and it is common for them to wear out and fail.
If it is the timing gear and chain, replace them both and install a good steel gear and chain.

 

Sure sounds like an ignition issue or related to me. Did you do ANY maintenance just before this happened or did it just happen out of the blue and it has been running OK? BTW, I've been to Incirlik Turkey and have fond memories of Adana bobs and Efes beer along with lots of pistachio's. GL with your 70.

 

thinking it could be the coil quit as it warmed up, or maybe a loose wire somewhere between the ignition switch and the distrib? don't know how the plugs were tested but seemed odd that some were weaker than others? also, a timing light might help going thru the plug wires to see if the spark is consistent x 8, just some diy thoughts

Hope you enjoy yr big block, really miss my "72!

 

Does your car have electronic ignition and if so what type or if points.

What voltage do you have to the ignition when trying to start vs normal run position ?

When you say you have spark did you pull the lead from a plug and check with a plug laying on a metal part of the engine?

 

If the ignition was swapped from points to electronic or hei, make sure they didn’t use the original resistance wire to the distributor.
That circuit is designed to reduce the voltage to 10.5 volts to protect the original points when starting the engine, but electronic and HEI ignitions require a full 12 volts when cranking the engine to start it.
You need a dedicated 12 volt wire.

 

Hello everyone again, I bought the distributor cap as my mechanic and you in the forum said. However, the new black one did not have metal conductors on it like the old red cap, then when I looked to see if there were any on the cable, there were none on the cable either. Either the red cap is original or the black cap, I do not know which one is correct, I am waiting for your support, thanks in advance

 

So in the end it didn't work because there were no conductors on the cover but it fit into the slot.

 

Your distributor is an aftermarket distributor and the red cap is probably the correct type cap for that distributor.
The black cap you purchased is for an original equipment type distributor and while it may fit, it is not correct for your distributor.
You’ll need to find the correct cap for your distributor.
If your distributor doesn’t have any brand or part numbers on it, you’ll have to do some research to determine what the manufacturer was for that distributor so you can find the correct cap.
When I bought my 73 a prior owner had replaced the distributor for an aftermarket HEI that had no identifying brand or part numbers.
I couldn’t find the correct cap and so I just purchased a new MSD distributor.

 

Beautiful car you have there. Must be quite rare in Turkey. Enjoy!

Looks like you have a standard size distributor. Non Hei. It is not original since it has an aluminum body. With an internal electronic pickup module, no points. Uses clamp down caps. The red color means it may be an aftermarket MSD model or an overseas knock-off.

Your wires are set up for the aftermarket "tower" sockets. Factory uses a "socket" style, but would require different plug wires. These two styles are pretty standard. Racers prefer the MSD style, the wires may be better, they just do not look factory.
Just buy a new MSD style tower cap, and a new rotor. Summit Racing has them. 84335 is for the cap & rotor set.
Link:
Summit Racing




And yes the button in the cap can fail like that, and it happens quickly, without any drama, just dead.