When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm in need of some thoughts/advice on a situation I just started to experience. The car has been driving impeccably for the past month and started to feel little weird out of no where on my drive home yesterday.
I was able to get to my original destination without any signs of performance issues or any indications that one may arise. Then about 2 minutes into my short drive back home, I was in 3rd gear when the car started to lag a little when pressing the gas, then it started to sputter and not respond to acceleration for a second. I was able to down shift into 2nd and get home with no issues.
Driving it a little later to see what was going on and the car started to do the same thing, now in 2nd gear, but with even more sputtering and a backfire sound when I'd shift. It got to the point where I had to pull off to the side of the road and wait a few minutes before turning around, because it just wouldn't drive when I tried to accelerate.
A little back story: I purchased this car a little over a month ago and it's my first C3. I've had it looked over, oil/fluids changed, and it just had gotten new plug wires before I purchased. Some funky things I have noticed only within the past week: there are a few drop of some brownish/dark orangish fluid in the garage where it's parked, and there's been two times I've taken the ignition cylinder out when I turned the car off and it was really really warm/borderline too hot to touch.
I appreciate any insights and guidance y'all might have for me!
Sounds like it is either a fuel or spark issue.
First, remove the air cleaner and push the throttle linkage. You should see fuel squirt in the carb.
If no squirt, you most likely have a bad accelerator pump.
If you have squirt, check distributor for spark advance problem.
I am sure others will chime in with much more detailed instructions, but this should get you started with the diagnosis...
Sounds like fuel starvation to me, not related to the accelerator pump. Start with easy stuff like the fuel filter. Taking off the fuel line putting it into a container and cranking the engine to see how much fuel it delivers, checking fuel pressure etc.
Mechanical fuel pumps fail, and is the most likely cause if the filter is not clogged.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
look into the gas tank with a flashlight and see if there is any water or sludge floating around in there. You should be able to see the sock as well, it should look whiteish and look like a windsock. IF it isnt it maybe collapsed and blocking fuel flow. Get a fuel pressure gauge at the carb and see what pressure your pump is putting out, they go bad.
THEN I would get a bucket and put it under the fuel pump, disconnect it and let the fuel drain from the tank and pull the gauge / pickup out the bottom and check the sock. then blow through the lines with compressed air to see if it blows easily and if any sludge comes out. start there, then maybe have your carb rebuilt if its a Qjet or rebuild it yourself if you can read Cliff Ruggles book.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
When you say you took out the ignition cylinder out, are you talking about the ignition lock cylinder which is what you said or are you talking about the ignition coil which can get hot and they do go bad.
Also do you know what ignition points are and how to adjust the points and the dwell. IF you messed with the distributor you could have messed them up
When you say you took out the ignition cylinder out, are you talking about the ignition lock cylinder which is what you said or are you talking about the ignition coil which can get hot and they do go bad.
Also do you know what ignition points are and how to adjust the points and the dwell. IF you messed with the distributor you could have messed them up
Yes, I'm talking about the ignition lock cylinder, not the ignition coil.
I'm not aware of what ignition points are or how to adjust them. I'll do a little searching on here to see if it's something I could have altered by accident.
Originally Posted by HeadsU.P.
Sputter, lags, not respond to throttle?
And twice you pulled the ignition switch and it was burning up?
Look no further. And don't drive it. In fact, disconnect the NEG battery before you burn your garage down with the car in it.
Your IGN source going to ground. You no longer have 12 volts. So, the coil does not have 12V. Your plugs are not getting enough voltage to fire.
Why the need to pull the IGN switch? Starting issues? IGN key issues? There is a lot missing to this story.
My apologies on the miscommunication, Rescue Rogers helped me name the thing I'm talking about more appropriately, it's the ignition lock cylinder (see below for reference).
When I turn my car off, about 90% of the time I pull the key out the ignition lock cylinder comes out with it. On two occasions in the past week IGN lock cylinder was pretty dang hot to the touch!
Sounds like it is either a fuel or spark issue.
First, remove the air cleaner and push the throttle linkage. You should see fuel squirt in the carb.
If no squirt, you most likely have a bad accelerator pump.
If you have squirt, check distributor for spark advance problem.
I am sure others will chime in with much more detailed instructions, but this should get you started with the diagnosis...
Originally Posted by REELAV8R
Sounds like fuel starvation to me, not related to the accelerator pump. Start with easy stuff like the fuel filter. Taking off the fuel line putting it into a container and cranking the engine to see how much fuel it delivers, checking fuel pressure etc.
Mechanical fuel pumps fail, and is the most likely cause if the filter is not clogged.
Originally Posted by Rescue Rogers
look into the gas tank with a flashlight and see if there is any water or sludge floating around in there. You should be able to see the sock as well, it should look whiteish and look like a windsock. IF it isnt it maybe collapsed and blocking fuel flow. Get a fuel pressure gauge at the carb and see what pressure your pump is putting out, they go bad.
THEN I would get a bucket and put it under the fuel pump, disconnect it and let the fuel drain from the tank and pull the gauge / pickup out the bottom and check the sock. then blow through the lines with compressed air to see if it blows easily and if any sludge comes out. start there, then maybe have your carb rebuilt if its a Qjet or rebuild it yourself if you can read Cliff Ruggles book.
Thank you all for some actionable things to do and look for!! I'll report back with any progress
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Your ignition switch could be bad. I had similar issues that kept changing symptoms. That switch should never get hot. The key lock just switches the positions but if the switch its in is having issues the heat can transfer.
Be aware that as far as I know the 68 ignition switch replacements do not have the light bulb receptical cast into them. I would buy one from Lectric Limited if they make them. Lou.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Lou is right. You can find new in the box originals on ebay but you will pay 3 x the price. I did cause its worth every penny to have original electrical parts
Looking into new ignition switches now, including ebay!
I ran all the diagnostics suggested and can report back that the only issue I came across was maybe the sock in the fuel tank. I researched what it's supposed to look like but each time i try to look in the tank I just notice the reflection of the opening and do not see a sock (image below).
For a multi pronged approach, I'm replacing the air filter, & fuel filter, now the ignition switch and maybe the sock.
I can see the sock in your picture, but the black stuff could be the sock has disintigrated and breaking apart. Lou.
...yep, the sock is definitely there, just looks black instead of white-probably clogged with dirt, dust, debris. You also may have water or moisture in the fuel in that tank. Water will be at the bottom and will look like small pools, or bubbles.
Making some progress as parts come in and time permits during the holidays.
After emptying the gas tank and pulling out the sending unit, I was able to figure out the tank isn't rusted out and that the sock was completely ripped:
Also, the fuel filter next to the tank was disgusting:
Going to be blowing the fuel lines out with an air compressor and attaching a new filter as it comes in (luckily had bought a sending unit sock & gas tank ring/gasket on a feeling.)
Just wanted some thoughts on why it could have gotten so dirty and beyond putting an additive in with the fuel what can I do to clear this up, then also keep it from happening again 🤔
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
The red stuff is rust, probably from condensation, some of the other bits could be from the old sock or the inside of the filter coming apart. I would flush the lines to see if they are fullnof crap and replace the pickup. Did you say the inside of the tank is rust free?
Im guessing the p.o. was having issues with crap makingnit from his tank to the carb and thats why that filter is thrre. Its not an OEM filter.....stock filters were in the carbs
The red stuff is rust, probably from condensation, some of the other bits could be from the old sock or the inside of the filter coming apart. I would flush the lines to see if they are fullnof crap and replace the pickup. Did you say the inside of the tank is rust free?
Im guessing the p.o. was having issues with crap makingnit from his tank to the carb and thats why that filter is thrre. Its not an OEM filter.....stock filters were in the carbs
Looking into replacing the pickup now and even the tank (upon further examination once it dried and I got some more videos of the inside, it was looking crusty and little rusty.)
Just bypassed that other filter since it's not OEM, added some Marvel's Mystery Oil back to the fuel I took out because that was all clear, and the car has been doing better than it has in my possession!!
Truly appreciate your input and guidance Double R!!