1990 corvette problem
Thread Starter
Advanced
Joined: Oct 2025
Posts: 57
Likes: 2
From: des moines
1990 corvette problem
Hey guys, I’ve got a 1990 Corvette C4 and I recently replaced the passenger-side exhaust manifold. After the install, I took it for a drive and noticed my voltage dropped to 0. The car started back up for a few moments but then died again, so I had to tow it home.
It’ll start if I spray starter fluid, but it won’t stay running. I let it sit for a couple of days, and now it only cranks over once before stopping. When I turn the key, it makes a really loud clicking noise and then the car “dies.” The battery is fully charged, the starter works fine, and the fuel pump is brand new.
Could this be a fuel problem or something electrical? Any ideas on where I should start looking?
It’ll start if I spray starter fluid, but it won’t stay running. I let it sit for a couple of days, and now it only cranks over once before stopping. When I turn the key, it makes a really loud clicking noise and then the car “dies.” The battery is fully charged, the starter works fine, and the fuel pump is brand new.
Could this be a fuel problem or something electrical? Any ideas on where I should start looking?
Drifting
Joined: Sep 2022
Posts: 1,480
Likes: 395
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
A second thread will not help folks work with you through your issue.
The way it tends to work is you give the symptoms and folks talk through the possibles. it doesn't always go quickly - be patient.
When a suggestion is given either try it, or explain why you don't want to try it, or that you already have. But remember this. Many folks here have a massive amount of experience with these specific 30+ year old cars. They want to help but they have their own lives to live. Talk things through, be thorough in your replies - we aren't there to see things.
And my last thought... remember the car's computer is in control. It thinks that everything is still the way it was when it left the factory. Sensors that look good might not be. Connections could have buildup on them. Everything has been worn down over time. Good Luck.
The way it tends to work is you give the symptoms and folks talk through the possibles. it doesn't always go quickly - be patient.
When a suggestion is given either try it, or explain why you don't want to try it, or that you already have. But remember this. Many folks here have a massive amount of experience with these specific 30+ year old cars. They want to help but they have their own lives to live. Talk things through, be thorough in your replies - we aren't there to see things.
And my last thought... remember the car's computer is in control. It thinks that everything is still the way it was when it left the factory. Sensors that look good might not be. Connections could have buildup on them. Everything has been worn down over time. Good Luck.
Melting Slicks
Joined: May 2003
Posts: 2,078
Likes: 281
From: Dyersburg TN
A lot going on, maybe overlapping failures so here goes...
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
Thread Starter
Advanced
Joined: Oct 2025
Posts: 57
Likes: 2
From: des moines
A lot going on, maybe overlapping failures so here goes...
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
Thread Starter
Advanced
Joined: Oct 2025
Posts: 57
Likes: 2
From: des moines
A lot going on, maybe overlapping failures so here goes...
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
"my voltage drops to zero" - if alternator is working you should have around 14.5 volts. If alternator dies it will drop to around 12.0 volts then slowly lower as battery is used. A sudden drop to zero is an open circuit. Start checking cables at battery. There is a large junction box also right beside the battery.
"start if I spray starter fluid" - you got no fuel. Bad fuse, bad relay or bad pump. Check pressure at fuel rail with a gauge then check fuse and relay with test light
"really loud clicking noise" - this is usually a discharged battery or bad starter solenoid. Starter solenoid engages (first click), amperage jumps as motor tries to run causing loose connection / bad solenoid to fail and solenoid releases (second click). Have the battery checked and put a charger on it overnight.
Good luck with your car. Post results here to further zero in on issues
Drifting
Joined: Nov 2018
Posts: 1,798
Likes: 579
From: Mays Landing, NJ
It could be the pump. When you turn the key to on position (not start position) do you hear the pump come on for a couple of seconds? You may need someone to turn the key so you can listen at rear of car. If you don't hear it running you may indeed have a bad pump, but it would be safe to put a volt meter on the hot wire at pump to ensure its actually getting 12 volts.
Drifting
Joined: Nov 2018
Posts: 1,760
Likes: 647
From: USA
Hey guys, I’ve got a 1990 Corvette C4 and I recently replaced the passenger-side exhaust manifold. After the install, I took it for a drive and noticed my voltage dropped to 0. The car started back up for a few moments but then died again, so I had to tow it home.
It’ll start if I spray starter fluid, but it won’t stay running. I let it sit for a couple of days, and now it only cranks over once before stopping. When I turn the key, it makes a really loud clicking noise and then the car “dies.” The battery is fully charged, the starter works fine, and the fuel pump is brand new.
Could this be a fuel problem or something electrical? Any ideas on where I should start looking?
It’ll start if I spray starter fluid, but it won’t stay running. I let it sit for a couple of days, and now it only cranks over once before stopping. When I turn the key, it makes a really loud clicking noise and then the car “dies.” The battery is fully charged, the starter works fine, and the fuel pump is brand new.
Could this be a fuel problem or something electrical? Any ideas on where I should start looking?
