88 Corvette won’t start
Thread Starter
7th Gear
Joined: Sep 2020
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88 Corvette won’t start
So my 88 has been sitting for about 8 years and I’ve already replaced fuel sensing unit, fuel pump and filter. MAF relay and burn off relay as well as fuel pump relay. The problem I’m having is the car cranks and won’t start unless I use starting fluid and even at that it will stall out and I’ll have to spray again and play with the throttle for it to not stall out. MAF plugged in or not it’s always the same. But once warmed up it will start. The other issue is once started if I try to throttle it the engine boggles down so it basically idles perfect once warm. Any help is great fully appreciated so thanks in advance!
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Joined: Sep 2013
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From: Cape Coral, Florida
If it starts will starting fluid you obviously have a fuel delivery issue so I would look at the fuel pump...did you look at fuel pressure and associated wiring ??
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Hello Jacob Cardona,
Welcome to the Corvette Forum!
On my 1988 Coupe I was surprised after letting the car sit for a year or more the fuel supply line was rusted shut internally by the water absorbed by the Ethanol. I had to run a new fuel supply line to get the engine to run properly. I measured the fuel flow over time of the factory supply line and a rubber line, this made the problem very obvious as the factory supply line could not supply enough to drive the Corvette. I also had a brake line that popped as soon as I stepped on it hard. Had to replace the brake lines on the 1988 which is not a fun job.
Do you have a Fuel Pressure Gauge to see what kind of pressures your fuel system is making? How about the Factory Service Manuals for the 1988 model year Corvette? Both are critical for owning a 1988 C4 and keeping it on the road.
The other BIG problem I had was voltages were not close to 12 volts inside the car. Measure the battery voltage at the battery, next measure it at the fuse panel on end of dashboard on passengers side. If the two are the same you are okay, if the voltages are different then you have likely got corrosion on the post where the fusible links get their power from. I removed the ring connectors and cleaned each one and the post itself. When re-assembled the fuse panel had the same voltage as the batteries. My radio had 12 volts supplied to it instead of 10.2 or whatever it was. Since you have opened it up before I would be curious what voltage the fuel pump is getting while running, the fuel pump runs a whole lot better on 12 volts than 10 Vdc.
I have also had full power go to a fuse but not get through the fuse (even thought it is good) due to corrosion on aluminum bladed fuses. That was easy, just replace them with quality fuses...
At 8 years without running you will definitely need a new Oxygen Sensor as they are only good for 24 months. The same goes for the Fuel Pressure Regulator as it has a replaceable diaphragm that is "eaten up" my the ethanol in todays gasoline. If you have not replaced it already you will need to replace this as well. Also look for bad Vacuum leaks. The hoses on these cars have dried up and started falling apart. I would replace every single hose on the engine coolant system and vacuum system. Be sure the EGR Vacuum Solenoid is still functional by making sure it gets the vacuum signal and that the EGR valve can move a bit when vacuum is applied.
Do you have access to a scanner or something that would allow you to see the engine in action? This would really help. See if you know anybody with a scanner, it has to be able to work on the OBD1 cars like your Corvette. I bought a Snap On MT2500 from a fellow member and love being able to watch the engine working.
You need to stop throwing parts at the Corvette, this gets very expensive fast. The other thing is don't "run" the engine on Starting fluid too often as it is hard on the pistons and rings. Certainly don't "Keep it running" with starter fluid...
Your Corvette should prime the fuel system when the key is turned to start. You need to follow a trouble shooting chart in the FSM as it is designed with only the Corvettes in mind. The FSM's are a two book set for the 1988, one mechanical and one electrical. You really need to have these if you plan on owning an older Corvette.
Drain the old gas out and fill it with good fresh fuel. Check the distributor cap and make sure the ignition is working by verifying the spark at each cylinder. Also check the spark, is it a bright flash or a weak spark? I use a tool that I can measure the strength of the spark with. At some point you might try a NOID device to verify that your eight fuel injectors are still working properly. After eight years I would seriously think about replacing them with newer units as the old ones fail using Ethanol through them. After 8 years of sitting I would replace them. I use South Bay Injectors but there are plenty of suppliers out there. While you are at it you might change the spark plugs and wires as they are older and might start failing.
Does the engine have fresh oil in it? That has to be changed out right away, you don't want to use 8 year old oil. You might want to add a quart of Marvel Mystery Oil to the engine oil to help loosen things back up. I would change it again after another 100 miles and drain it and fill it with good fresh oil.
While trouble shooting you might unplug the power going to the 9th injector in case it is dumping raw fuel into your engine. It is located on the drivers side rear of the intake plenum. Sometimes they get stuck open or closed, either way you want to rule it out as the main issue.
Any questions and we would be happy to help you. There are enough of us on this Forum to figure out what is wrong with your 1988 C4! I have had mine for close to 25 years and fixed just about everything.
Welcome to the Corvette Forum!
On my 1988 Coupe I was surprised after letting the car sit for a year or more the fuel supply line was rusted shut internally by the water absorbed by the Ethanol. I had to run a new fuel supply line to get the engine to run properly. I measured the fuel flow over time of the factory supply line and a rubber line, this made the problem very obvious as the factory supply line could not supply enough to drive the Corvette. I also had a brake line that popped as soon as I stepped on it hard. Had to replace the brake lines on the 1988 which is not a fun job.
Do you have a Fuel Pressure Gauge to see what kind of pressures your fuel system is making? How about the Factory Service Manuals for the 1988 model year Corvette? Both are critical for owning a 1988 C4 and keeping it on the road.
The other BIG problem I had was voltages were not close to 12 volts inside the car. Measure the battery voltage at the battery, next measure it at the fuse panel on end of dashboard on passengers side. If the two are the same you are okay, if the voltages are different then you have likely got corrosion on the post where the fusible links get their power from. I removed the ring connectors and cleaned each one and the post itself. When re-assembled the fuse panel had the same voltage as the batteries. My radio had 12 volts supplied to it instead of 10.2 or whatever it was. Since you have opened it up before I would be curious what voltage the fuel pump is getting while running, the fuel pump runs a whole lot better on 12 volts than 10 Vdc.
I have also had full power go to a fuse but not get through the fuse (even thought it is good) due to corrosion on aluminum bladed fuses. That was easy, just replace them with quality fuses...
At 8 years without running you will definitely need a new Oxygen Sensor as they are only good for 24 months. The same goes for the Fuel Pressure Regulator as it has a replaceable diaphragm that is "eaten up" my the ethanol in todays gasoline. If you have not replaced it already you will need to replace this as well. Also look for bad Vacuum leaks. The hoses on these cars have dried up and started falling apart. I would replace every single hose on the engine coolant system and vacuum system. Be sure the EGR Vacuum Solenoid is still functional by making sure it gets the vacuum signal and that the EGR valve can move a bit when vacuum is applied.
Do you have access to a scanner or something that would allow you to see the engine in action? This would really help. See if you know anybody with a scanner, it has to be able to work on the OBD1 cars like your Corvette. I bought a Snap On MT2500 from a fellow member and love being able to watch the engine working.
You need to stop throwing parts at the Corvette, this gets very expensive fast. The other thing is don't "run" the engine on Starting fluid too often as it is hard on the pistons and rings. Certainly don't "Keep it running" with starter fluid...
Your Corvette should prime the fuel system when the key is turned to start. You need to follow a trouble shooting chart in the FSM as it is designed with only the Corvettes in mind. The FSM's are a two book set for the 1988, one mechanical and one electrical. You really need to have these if you plan on owning an older Corvette.
Drain the old gas out and fill it with good fresh fuel. Check the distributor cap and make sure the ignition is working by verifying the spark at each cylinder. Also check the spark, is it a bright flash or a weak spark? I use a tool that I can measure the strength of the spark with. At some point you might try a NOID device to verify that your eight fuel injectors are still working properly. After eight years I would seriously think about replacing them with newer units as the old ones fail using Ethanol through them. After 8 years of sitting I would replace them. I use South Bay Injectors but there are plenty of suppliers out there. While you are at it you might change the spark plugs and wires as they are older and might start failing.
Does the engine have fresh oil in it? That has to be changed out right away, you don't want to use 8 year old oil. You might want to add a quart of Marvel Mystery Oil to the engine oil to help loosen things back up. I would change it again after another 100 miles and drain it and fill it with good fresh oil.
While trouble shooting you might unplug the power going to the 9th injector in case it is dumping raw fuel into your engine. It is located on the drivers side rear of the intake plenum. Sometimes they get stuck open or closed, either way you want to rule it out as the main issue.
Any questions and we would be happy to help you. There are enough of us on this Forum to figure out what is wrong with your 1988 C4! I have had mine for close to 25 years and fixed just about everything.
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
Hello Jacob Cardona,
Welcome to the Corvette Forum!
On my 1988 Coupe I was surprised after letting the car sit for a year or more the fuel supply line was rusted shut internally by the water absorbed by the Ethanol. I had to run a new fuel supply line to get the engine to run properly. I measured the fuel flow over time of the factory supply line and a rubber line, this made the problem very obvious as the factory supply line could not supply enough to drive the Corvette. I also had a brake line that popped as soon as I stepped on it hard. Had to replace the brake lines on the 1988 which is not a fun job.
Do you have a Fuel Pressure Gauge to see what kind of pressures your fuel system is making? How about the Factory Service Manuals for the 1988 model year Corvette? Both are critical for owning a 1988 C4 and keeping it on the road.
The other BIG problem I had was voltages were not close to 12 volts inside the car. Measure the battery voltage at the battery, next measure it at the fuse panel on end of dashboard on passengers side. If the two are the same you are okay, if the voltages are different then you have likely got corrosion on the post where the fusible links get their power from. I removed the ring connectors and cleaned each one and the post itself. When re-assembled the fuse panel had the same voltage as the batteries. My radio had 12 volts supplied to it instead of 10.2 or whatever it was. Since you have opened it up before I would be curious what voltage the fuel pump is getting while running, the fuel pump runs a whole lot better on 12 volts than 10 Vdc.
I have also had full power go to a fuse but not get through the fuse (even thought it is good) due to corrosion on aluminum bladed fuses. That was easy, just replace them with quality fuses...
At 8 years without running you will definitely need a new Oxygen Sensor as they are only good for 24 months. The same goes for the Fuel Pressure Regulator as it has a replaceable diaphragm that is "eaten up" my the ethanol in todays gasoline. If you have not replaced it already you will need to replace this as well. Also look for bad Vacuum leaks. The hoses on these cars have dried up and started falling apart. I would replace every single hose on the engine coolant system and vacuum system. Be sure the EGR Vacuum Solenoid is still functional by making sure it gets the vacuum signal and that the EGR valve can move a bit when vacuum is applied.
Do you have access to a scanner or something that would allow you to see the engine in action? This would really help. See if you know anybody with a scanner, it has to be able to work on the OBD1 cars like your Corvette. I bought a Snap On MT2500 from a fellow member and love being able to watch the engine working.
You need to stop throwing parts at the Corvette, this gets very expensive fast. The other thing is don't "run" the engine on Starting fluid too often as it is hard on the pistons and rings. Certainly don't "Keep it running" with starter fluid...
Your Corvette should prime the fuel system when the key is turned to start. You need to follow a trouble shooting chart in the FSM as it is designed with only the Corvettes in mind. The FSM's are a two book set for the 1988, one mechanical and one electrical. You really need to have these if you plan on owning an older Corvette.
Drain the old gas out and fill it with good fresh fuel. Check the distributor cap and make sure the ignition is working by verifying the spark at each cylinder. Also check the spark, is it a bright flash or a weak spark? I use a tool that I can measure the strength of the spark with. At some point you might try a NOID device to verify that your eight fuel injectors are still working properly. After eight years I would seriously think about replacing them with newer units as the old ones fail using Ethanol through them. After 8 years of sitting I would replace them. I use South Bay Injectors but there are plenty of suppliers out there. While you are at it you might change the spark plugs and wires as they are older and might start failing.
Does the engine have fresh oil in it? That has to be changed out right away, you don't want to use 8 year old oil. You might want to add a quart of Marvel Mystery Oil to the engine oil to help loosen things back up. I would change it again after another 100 miles and drain it and fill it with good fresh oil.
While trouble shooting you might unplug the power going to the 9th injector in case it is dumping raw fuel into your engine. It is located on the drivers side rear of the intake plenum. Sometimes they get stuck open or closed, either way you want to rule it out as the main issue.
Any questions and we would be happy to help you. There are enough of us on this Forum to figure out what is wrong with your 1988 C4! I have had mine for close to 25 years and fixed just about everything.
Welcome to the Corvette Forum!
On my 1988 Coupe I was surprised after letting the car sit for a year or more the fuel supply line was rusted shut internally by the water absorbed by the Ethanol. I had to run a new fuel supply line to get the engine to run properly. I measured the fuel flow over time of the factory supply line and a rubber line, this made the problem very obvious as the factory supply line could not supply enough to drive the Corvette. I also had a brake line that popped as soon as I stepped on it hard. Had to replace the brake lines on the 1988 which is not a fun job.
Do you have a Fuel Pressure Gauge to see what kind of pressures your fuel system is making? How about the Factory Service Manuals for the 1988 model year Corvette? Both are critical for owning a 1988 C4 and keeping it on the road.
The other BIG problem I had was voltages were not close to 12 volts inside the car. Measure the battery voltage at the battery, next measure it at the fuse panel on end of dashboard on passengers side. If the two are the same you are okay, if the voltages are different then you have likely got corrosion on the post where the fusible links get their power from. I removed the ring connectors and cleaned each one and the post itself. When re-assembled the fuse panel had the same voltage as the batteries. My radio had 12 volts supplied to it instead of 10.2 or whatever it was. Since you have opened it up before I would be curious what voltage the fuel pump is getting while running, the fuel pump runs a whole lot better on 12 volts than 10 Vdc.
I have also had full power go to a fuse but not get through the fuse (even thought it is good) due to corrosion on aluminum bladed fuses. That was easy, just replace them with quality fuses...
At 8 years without running you will definitely need a new Oxygen Sensor as they are only good for 24 months. The same goes for the Fuel Pressure Regulator as it has a replaceable diaphragm that is "eaten up" my the ethanol in todays gasoline. If you have not replaced it already you will need to replace this as well. Also look for bad Vacuum leaks. The hoses on these cars have dried up and started falling apart. I would replace every single hose on the engine coolant system and vacuum system. Be sure the EGR Vacuum Solenoid is still functional by making sure it gets the vacuum signal and that the EGR valve can move a bit when vacuum is applied.
Do you have access to a scanner or something that would allow you to see the engine in action? This would really help. See if you know anybody with a scanner, it has to be able to work on the OBD1 cars like your Corvette. I bought a Snap On MT2500 from a fellow member and love being able to watch the engine working.
You need to stop throwing parts at the Corvette, this gets very expensive fast. The other thing is don't "run" the engine on Starting fluid too often as it is hard on the pistons and rings. Certainly don't "Keep it running" with starter fluid...
Your Corvette should prime the fuel system when the key is turned to start. You need to follow a trouble shooting chart in the FSM as it is designed with only the Corvettes in mind. The FSM's are a two book set for the 1988, one mechanical and one electrical. You really need to have these if you plan on owning an older Corvette.
Drain the old gas out and fill it with good fresh fuel. Check the distributor cap and make sure the ignition is working by verifying the spark at each cylinder. Also check the spark, is it a bright flash or a weak spark? I use a tool that I can measure the strength of the spark with. At some point you might try a NOID device to verify that your eight fuel injectors are still working properly. After eight years I would seriously think about replacing them with newer units as the old ones fail using Ethanol through them. After 8 years of sitting I would replace them. I use South Bay Injectors but there are plenty of suppliers out there. While you are at it you might change the spark plugs and wires as they are older and might start failing.
Does the engine have fresh oil in it? That has to be changed out right away, you don't want to use 8 year old oil. You might want to add a quart of Marvel Mystery Oil to the engine oil to help loosen things back up. I would change it again after another 100 miles and drain it and fill it with good fresh oil.
While trouble shooting you might unplug the power going to the 9th injector in case it is dumping raw fuel into your engine. It is located on the drivers side rear of the intake plenum. Sometimes they get stuck open or closed, either way you want to rule it out as the main issue.
Any questions and we would be happy to help you. There are enough of us on this Forum to figure out what is wrong with your 1988 C4! I have had mine for close to 25 years and fixed just about everything.
I did change oil about six months ago when I started trying to get this car running again as well as drain and put fresh gas. I have already tried going through the hassle of removing the fuel injectors but I couldn’t get the bolts on the fuel rail loosened and I didn’t want them to snap so I just kind of put it back together and hoped it wasn’t that but I guess I’ll have to give it another shot.
The battery should be good as I just got it about a month ago and I don’t usually keep it connected. I usually Keep it disconnected until I want to attempt to start it.
ill look online for a FSM As well as that snap on connector you talked about Because I don’t have a scanner or know of anyone in my area that has one.I would actually rather buy one then take it to a mechanic.
Pro
Joined: Aug 2020
Posts: 647
Likes: 126
From: Liliha Bakery stuffing my face with coco puffs!
What's the temperature like in your neck of the woods? I'm just wondering if a non functioning cold start injector is part of the problem. Engine temps above ~93*F it is not in use for engine start. If in use during start, stays on for ~8 seconds.
Last edited by stew86MCSS396; Sep 28, 2020 at 04:07 AM.
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Hello again Jacob,
Disconnect the rubber line that attaches to the fuel output under the fuel pump plate over the gas tank filler. After you disconnect the supply line you can attach a rubber line and feed it into the fuel filter. I used a gallon glass bottle to catch the gasoline safely. Be sure to have a fire extinguisher at all times when working on the fuel tank. I ran the fuel pump with the original hose attached and then I bypassed the origninal fuel line.
Try heating the bolts up with a Hot air gun (NO Torch) and then apply penetrating oil to get sucked back into the joint.
The Snap On MT 2500 was the tool to have in the 1980's. They are very inexpensive today and fairly common on Ebay.
Disconnect the rubber line that attaches to the fuel output under the fuel pump plate over the gas tank filler. After you disconnect the supply line you can attach a rubber line and feed it into the fuel filter. I used a gallon glass bottle to catch the gasoline safely. Be sure to have a fire extinguisher at all times when working on the fuel tank. I ran the fuel pump with the original hose attached and then I bypassed the origninal fuel line.
Try heating the bolts up with a Hot air gun (NO Torch) and then apply penetrating oil to get sucked back into the joint.
The Snap On MT 2500 was the tool to have in the 1980's. They are very inexpensive today and fairly common on Ebay.
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
in San Antonio so it’s about 85. Temperatures always changing fast in Texas haha
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Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
Hello again Jacob,
Disconnect the rubber line that attaches to the fuel output under the fuel pump plate over the gas tank filler. After you disconnect the supply line you can attach a rubber line and feed it into the fuel filter. I used a gallon glass bottle to catch the gasoline safely. Be sure to have a fire extinguisher at all times when working on the fuel tank. I ran the fuel pump with the original hose attached and then I bypassed the origninal fuel line.
Try heating the bolts up with a Hot air gun (NO Torch) and then apply penetrating oil to get sucked back into the joint.
The Snap On MT 2500 was the tool to have in the 1980's. They are very inexpensive today and fairly common on Ebay.
Disconnect the rubber line that attaches to the fuel output under the fuel pump plate over the gas tank filler. After you disconnect the supply line you can attach a rubber line and feed it into the fuel filter. I used a gallon glass bottle to catch the gasoline safely. Be sure to have a fire extinguisher at all times when working on the fuel tank. I ran the fuel pump with the original hose attached and then I bypassed the origninal fuel line.
Try heating the bolts up with a Hot air gun (NO Torch) and then apply penetrating oil to get sucked back into the joint.
The Snap On MT 2500 was the tool to have in the 1980's. They are very inexpensive today and fairly common on Ebay.
