1991 C4 Corvette Basic not Starting
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Joined: Sep 2014
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From: San Antonio Tx
1991 C4 Corvette Basic not Starting
Hello experts I need help bad.
What could cause the car to start up and shut down? To me it is starving for gas because it fires turns on and turns right off. We have replaced the Oxygen sensor, plugs, wires Battery and distributor. Isn't there a throttle positioner that would cause the car to act like that? I checked the Firing on the wires and they are correct. I do not want to take it to the Dealer because they are expensive and I don't to take it to a shop because they rip you off and replace parts that do not need replacing. I am 60 years old and I have a broken rotator Cuff or I would do it. Thanks in advance for your help.
What could cause the car to start up and shut down? To me it is starving for gas because it fires turns on and turns right off. We have replaced the Oxygen sensor, plugs, wires Battery and distributor. Isn't there a throttle positioner that would cause the car to act like that? I checked the Firing on the wires and they are correct. I do not want to take it to the Dealer because they are expensive and I don't to take it to a shop because they rip you off and replace parts that do not need replacing. I am 60 years old and I have a broken rotator Cuff or I would do it. Thanks in advance for your help.
Team Owner
Joined: Jul 2004
Posts: 28,472
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From: Hartford WI
3 options
1. Fix your rotator cuff. I had a torn rotator cuff, torn bicep and ligament or was it tendon in my elbow when I was 46, fixed all 3 in the same day and was able to use the arm slightly to pull fuel injectors out of 2 jetskis within 2 weeks of surgery. Then go do your own diagnosis.
2. We can guess all day long, you can pay someone to put the parts on
3. You can find someone you can trust to do it since you can't DIY for the diagnostics.
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME. I can guess that your fuel pump isn't delivering the goods, the ignition module is flakey, the injectors are shot, your engine temp sensor is bad, your manifold temp sensor is bad, your IAC is bad, etc, etc but we need to get diagnostics first.
1. Fix your rotator cuff. I had a torn rotator cuff, torn bicep and ligament or was it tendon in my elbow when I was 46, fixed all 3 in the same day and was able to use the arm slightly to pull fuel injectors out of 2 jetskis within 2 weeks of surgery. Then go do your own diagnosis.
2. We can guess all day long, you can pay someone to put the parts on
3. You can find someone you can trust to do it since you can't DIY for the diagnostics.
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME. I can guess that your fuel pump isn't delivering the goods, the ignition module is flakey, the injectors are shot, your engine temp sensor is bad, your manifold temp sensor is bad, your IAC is bad, etc, etc but we need to get diagnostics first.
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Joined: Aug 2000
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not sure what your limitations are with the broken cuff - ???
do you have a FSM? if not, get one. don't just start throwing parts at the thing. do proper, systematic, troubleshooting.
do you have any codes?
first thing I would do is check fuel pressure. do you hear your fuel pump kick on for a couple seconds when you first turn the key on? install a fuel pressure gauge on the Schrader valve - key on, you should get approximately 42psi for a couple seconds, then pressure should drop to around 37psi and hold for some period of time.
(my best guess) it almost sounds like the fuel pump is DOA, but without me under the hood, i'm just second guessing. start with the basics - fuel, spark, timing.... as for the fuel pump, it could be something as simple as a blown fuse - ???
good luck - keep us informed.
do you have a FSM? if not, get one. don't just start throwing parts at the thing. do proper, systematic, troubleshooting.
do you have any codes?
first thing I would do is check fuel pressure. do you hear your fuel pump kick on for a couple seconds when you first turn the key on? install a fuel pressure gauge on the Schrader valve - key on, you should get approximately 42psi for a couple seconds, then pressure should drop to around 37psi and hold for some period of time.
(my best guess) it almost sounds like the fuel pump is DOA, but without me under the hood, i'm just second guessing. start with the basics - fuel, spark, timing.... as for the fuel pump, it could be something as simple as a blown fuse - ???
good luck - keep us informed.
Last edited by Joe C; Jul 16, 2016 at 04:53 AM.
Thread Starter
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Joined: Sep 2014
Posts: 64
Likes: 1
From: San Antonio Tx
1991 Corvette C4 Basic Starts and dies in an instant
Hello I thought I did mention that the Spark Plugs are new, Wires are new and Distributor is new as well the Rotor. I pulled the #1 plug and it was carboned up. I don’t know if the shops did not change them out. I put one new plug back in #1 and see what it looks like after I run it some, I just need it to run first.
How do I check Fuel Pressure, is there a gauge or Shadetree way to do it?
What is a FSM, scanner, DVOM and a fuel pressure gauge?
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME.
Hello I thought I did mention that the Spark Plugs are new, Wires are new and Distributor is new as well the Rotor. I pulled the #1 plug and it was carboned up. I don’t know if the shops did not change them out. I put one new plug back in #1 and see what it looks like after I run it some, I just need it to run first.
How do I check Fuel Pressure, is there a gauge or Shadetree way to do it?
What is a FSM, scanner, DVOM and a fuel pressure gauge?
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME.
Thread Starter
Advanced
Joined: Sep 2014
Posts: 64
Likes: 1
From: San Antonio Tx
Hello,
What is a Schrader valve and where is it located? Do you have a Link that you use for your questions?
do you have a FSM? if not, get one. don't just start throwing parts at the thing. do proper, systematic, troubleshooting.
do you have any codes?
first thing I would do is check fuel pressure. do you hear your fuel pump kick on for a couple seconds when you first turn the key on? install a fuel pressure gauge on the Schrader valve - key on, you should get approximately 42psi for a couple seconds, then pressure should drop to around 37psi and hold for some period of time.
(my best guess) it almost sounds like the fuel pump is DOA, but without me under the hood, i'm just second guessing. start with the basics - fuel, spark, timing.... as for the fuel pump, it could be something as simple as a blown fuse - ???
good luck - keep us informed.[/QUOTE]
What is a Schrader valve and where is it located? Do you have a Link that you use for your questions?
do you have a FSM? if not, get one. don't just start throwing parts at the thing. do proper, systematic, troubleshooting.
do you have any codes?
first thing I would do is check fuel pressure. do you hear your fuel pump kick on for a couple seconds when you first turn the key on? install a fuel pressure gauge on the Schrader valve - key on, you should get approximately 42psi for a couple seconds, then pressure should drop to around 37psi and hold for some period of time.
(my best guess) it almost sounds like the fuel pump is DOA, but without me under the hood, i'm just second guessing. start with the basics - fuel, spark, timing.... as for the fuel pump, it could be something as simple as a blown fuse - ???
good luck - keep us informed.
[/QUOTE]
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
I pulled the #1 plug and it was carboned up. I don’t know if the shops did not change them out. I put one new plug back in #1 and see what it looks like after I run it some, I just need it to run first.
How do I check Fuel Pressure, is there a gauge or Shadetree way to do it?
What is a FSM, scanner, DVOM and a fuel pressure gauge?
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME.
How do I check Fuel Pressure, is there a gauge or Shadetree way to do it?
What is a FSM, scanner, DVOM and a fuel pressure gauge?
You need to be able to check spark, fuel pressure, plug wire integrity, spark quality, have a FSM, scanner, DVOM and a fuel pressure gauge to begin. Asking us to tell you what we think is wrong is no different from us guessing ON YOUR DIME.
You are going to have to get a gauge on it. There usually is a way or ways to check it that are good and the Shadetree way probably won't be as good. Longest distance between 2 points is the shortcut. FUEL RAIL. Look at the left rail. There is a nipple there. You need to get a fuel pressure gauge on the rail, turn it on and see what it does.
Factory Shop Manual, Scanner (something that can read data from the ECM and NOT a code reader), Digital Volt Ohm Meter, FUEL PRESSURE GAUGE.
To check if the plug wires are good, get a spray bottle and spray the finest mist you can AROUND, NOT AT, AROUND the plug wires. Do this in a dark garage so you can see if there is any electrical activity. IF there is, your wires are leaking.
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Joined: Sep 2014
Posts: 64
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From: San Antonio Tx
Hey the Plug wires are new. I was thinking about what you said starting it up in the dark looking for jumping fire. I will do that next.
I'm not sure why but it could be that it isn't igniting properly. Hard to say until we get it running.
You are going to have to get a gauge on it. There usually is a way or ways to check it that are good and the Shadetree way probably won't be as good. Longest distance between 2 points is the shortcut. FUEL RAIL. Look at the left rail. There is a nipple there. You need to get a fuel pressure gauge on the rail, turn it on and see what it does.
Factory Shop Manual, Scanner (something that can read data from the ECM and NOT a code reader), Digital Volt Ohm Meter, FUEL PRESSURE GAUGE.
To check if the plug wires are good, get a spray bottle and spray the finest mist you can AROUND, NOT AT, AROUND the plug wires. Do this in a dark garage so you can see if there is any electrical activity. IF there is, your wires are leaking.
You are going to have to get a gauge on it. There usually is a way or ways to check it that are good and the Shadetree way probably won't be as good. Longest distance between 2 points is the shortcut. FUEL RAIL. Look at the left rail. There is a nipple there. You need to get a fuel pressure gauge on the rail, turn it on and see what it does.
Factory Shop Manual, Scanner (something that can read data from the ECM and NOT a code reader), Digital Volt Ohm Meter, FUEL PRESSURE GAUGE.
To check if the plug wires are good, get a spray bottle and spray the finest mist you can AROUND, NOT AT, AROUND the plug wires. Do this in a dark garage so you can see if there is any electrical activity. IF there is, your wires are leaking.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Then put a known good plug and crank. Do this for each wire and ground the threads. If it sparks, it has to be a strong blue flame. Orange and you have other issues.
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Thread Starter
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Joined: Sep 2014
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From: San Antonio Tx
We know that we have Fire because it starts up for 30 Secs and then shuts off. I am still gonna do the night time test Thank you.
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not sure what you mean referring to a "question link" - ???
Last edited by Joe C; Jul 15, 2016 at 08:58 AM.
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From: Hartford WI
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Sounds like a problem with the VAT system (vehicle anti theft) if the VAT system is not functioning correctly the car will start briefly but shut off immediately. The Security light on the lower left corner of the dash will be on and/or flashing. You can override it, but my advice would be to get it to the dealer and have the issue fixed.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
Sounds like a problem with the VAT system (vehicle anti theft) if the VAT system is not functioning correctly the car will start briefly but shut off immediately. The Security light on the lower left corner of the dash will be on and/or flashing. You can override it, but my advice would be to get it to the dealer and have the issue fixed.
Last edited by Joe C; Jul 16, 2016 at 08:50 AM.
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Joined: Sep 2014
Posts: 64
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From: San Antonio Tx
Fixed it guys. Dumped the fuel tank Added Sta-Bill, Sea Foam, Marvel MYSTERY oIL. Squirted Fuel (high test) in Cyl #1, Checked firing order, got Ms. Rudolf from New Orleans Bourbon St. to give an incandation using her Monkey Foot and it fired right off. The Monkey will never be the same.
Thanks guys I learned a lot. You want something right do it your self. I got the little 16 yr old girl from Oreilly's to raise and lower the hood since I still have a Broken Right Shoulder Cuff. What an adventure! What do you suppose is in Marvel Mystery oil?
Thanks guys I learned a lot. You want something right do it your self. I got the little 16 yr old girl from Oreilly's to raise and lower the hood since I still have a Broken Right Shoulder Cuff. What an adventure! What do you suppose is in Marvel Mystery oil?
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Sounds like a problem with the VAT system (vehicle anti theft) if the VAT system is not functioning correctly the car will start briefly but shut off immediately. The Security light on the lower left corner of the dash will be on and/or flashing. You can override it, but my advice would be to get it to the dealer and have the issue fixed.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Fixed it guys. Dumped the fuel tank Added Sta-Bill, Sea Foam, Marvel MYSTERY oIL. Squirted Fuel (high test) in Cyl #1, Checked firing order, got Ms. Rudolf from New Orleans Bourbon St. to give an incandation using her Monkey Foot and it fired right off. The Monkey will never be the same.
Thanks guys I learned a lot. You want something right do it your self. I got the little 16 yr old girl from Oreilly's to raise and lower the hood since I still have a Broken Right Shoulder Cuff. What an adventure! What do you suppose is in Marvel Mystery oil?
Thanks guys I learned a lot. You want something right do it your self. I got the little 16 yr old girl from Oreilly's to raise and lower the hood since I still have a Broken Right Shoulder Cuff. What an adventure! What do you suppose is in Marvel Mystery oil?
According to an NTSB post aircraft accident investigation published in 2003, a Marvel Mystery Oil sample tested was composed of 74 percent mineral oil, 25 percent stoddard solvent, and 1 percent lard.[3]
According to the company's 2015 safety data sheet:[7]
Petroleum Distillates (Hydrotreated Heavy Naphthenic) also known as mineral oil 60-100%[7]
Petroleum Distillates (Stoddard Solvent) also known as white spirit 10-30%[7]
Tricresyl phosphate 0.1-1.0%[7]
Ortho Dichlorobenzene 0.1-1.0%[7]
Para Dichlorobenzene <0.1%[7]
According to the company's 2015 safety data sheet:[7]
Petroleum Distillates (Hydrotreated Heavy Naphthenic) also known as mineral oil 60-100%[7]
Petroleum Distillates (Stoddard Solvent) also known as white spirit 10-30%[7]
Tricresyl phosphate 0.1-1.0%[7]
Ortho Dichlorobenzene 0.1-1.0%[7]
Para Dichlorobenzene <0.1%[7]