96 lt1 cranks, won't start
Thread Starter
Intermediate
Joined: Aug 2004
Posts: 47
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From: Hartselle Alabama
96 lt1 cranks, won't start
This has happened one time before. I get in the car to start it, it cranks over for a second and i let off the key, expecting the engine to start. It doesn't start, seems like I just needed to hold it for a second longer.
After that happens, the car just turns over and over and will not start. Last time this happened, I came back a few hours later and it started on the first try (it didn't start nearly as easily as it does under normal circumstances.)
Today, same thing happened. Tried to start, but it just cranks and cranks. Came back after work, and still won't start.
Since it cranks i guess it's not a VATS or a starter problem. What could it be?
After that happens, the car just turns over and over and will not start. Last time this happened, I came back a few hours later and it started on the first try (it didn't start nearly as easily as it does under normal circumstances.)
Today, same thing happened. Tried to start, but it just cranks and cranks. Came back after work, and still won't start.
Since it cranks i guess it's not a VATS or a starter problem. What could it be?
Melting Slicks
Joined: Oct 2006
Posts: 2,238
Likes: 10
From: College Station TX
You need 3 things to run: compression, spark, and fuel. Since I doubt you lost compression, you are missing either spark and/or fuel. The first step is to determine which you are missing. Have someone crank it while you hold a spark plug to check for spark, and then make sure you have fuel at the fuel rail by pushing on the Schrader valve.
Melting Slicks
Joined: Oct 2006
Posts: 2,238
Likes: 10
From: College Station TX
Thread Starter
Intermediate
Joined: Aug 2004
Posts: 47
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From: Hartselle Alabama
something I forgot to add:
about a month ago the small coolant hose on the throttle body blew off at 80mph, spraying coolant all over the front of the engine (including the damn opti). I reconnected the hose and tightened the clamp. It cranked and cranked, didn't start. 10 minutes later, it started.
I'm pretty sure the opti got wet, and this problem happened AFTER the coolant incident...
about a month ago the small coolant hose on the throttle body blew off at 80mph, spraying coolant all over the front of the engine (including the damn opti). I reconnected the hose and tightened the clamp. It cranked and cranked, didn't start. 10 minutes later, it started.
I'm pretty sure the opti got wet, and this problem happened AFTER the coolant incident...
Pro
Joined: May 2006
Posts: 536
Likes: 0
From: Humble Texas
not talking down about any one that helps on here because without these guys my car wouldnt be on the road..
if I were you id buy a inexpensive fuel pressure gauge. dont know if you have companys like Harbor Freight, I picked one up for $12.00
thou I had pressure when i relieved it from the shrader valve it wasnt
enough to crank the car... I also replaced my opti cap and rotor which
turned out to be my problem..as well as fuel pump...jus my 2 cents..
again I dont take anything away from these guys most of them have already gone through the problems and know what to look for..
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
I just went thru a whole ordeal similiar to yours on my 96 lt1
not talking down about any one that helps on here because without these guys my car wouldnt be on the road..
if I were you id buy a inexpensive fuel pressure gauge. dont know if you have companys like Harbor Freight, I picked one up for $12.00
thou I had pressure when i relieved it from the shrader valve it wasnt
enough to crank the car... I also replaced my opti cap and rotor which
turned out to be my problem..as well as fuel pump...jus my 2 cents..
again I dont take anything away from these guys most of them have already gone through the problems and know what to look for..
not talking down about any one that helps on here because without these guys my car wouldnt be on the road..
if I were you id buy a inexpensive fuel pressure gauge. dont know if you have companys like Harbor Freight, I picked one up for $12.00
thou I had pressure when i relieved it from the shrader valve it wasnt
enough to crank the car... I also replaced my opti cap and rotor which
turned out to be my problem..as well as fuel pump...jus my 2 cents..
again I dont take anything away from these guys most of them have already gone through the problems and know what to look for..
If I had a coolant leak that doused the Opti, and it didn't crank back up right away, I would remove WP(replace if old), and dis-assemble Opti and clean out any moisture/coolant that may be in there. Depending on age and condition of the Opti, I would replace if necessary. Even though you have the vented Opti, if it took a big gulp of coolant somehow, this could casue problems when you least expect them.Did your starting problem you describe start immediatley after the coolant hose leak, or is this recent ???????
But.........as others have said, first check fuel pressure, followed by spark, as these are easy to do.
Thread Starter
Intermediate
Joined: Aug 2004
Posts: 47
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From: Hartselle Alabama
I've only had the car for a couple of months. The starting problem has happened 2 times, both happened after the coolant leak.
I'm going to check for fuel and spark. I hear the pump running when I try to start it, so I'm pretty sure fuel will be good. If it turns out it is a spark problem. then I'll look towards the opti.
I'm going to check for fuel and spark. I hear the pump running when I try to start it, so I'm pretty sure fuel will be good. If it turns out it is a spark problem. then I'll look towards the opti.
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From what you've described, my money's on the Opti. But check it out to be sure. No sense throwing money at parts, even though Opti's are considerably cheaper now than they were eight years ago when I purchased my 'Vette.
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Thread Starter
Intermediate
Joined: Aug 2004
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From: Hartselle Alabama
I finally got to check spark and fuel.
I primed the fuel pump by turning the key to ON, and then poked the schrader valve with a screwdriver. Fuel shot out of it with a pretty good amount of force (not exacly scientific lol)
Then I had my dad turn it over while I checked for spark. I pulled a plug wire on the passenger side and tried to arc it while the engine was cranking, both on the exhaust manifold and the plug itself. Did on driver side next.
I couldn't get the plug wire to arc on anything while the engine was cranking, so there's no spark.
Now that I know it's a spark problem, how do I determine whether its the optispark unit or something else in the ignition system?
I primed the fuel pump by turning the key to ON, and then poked the schrader valve with a screwdriver. Fuel shot out of it with a pretty good amount of force (not exacly scientific lol)
Then I had my dad turn it over while I checked for spark. I pulled a plug wire on the passenger side and tried to arc it while the engine was cranking, both on the exhaust manifold and the plug itself. Did on driver side next.
I couldn't get the plug wire to arc on anything while the engine was cranking, so there's no spark.
Now that I know it's a spark problem, how do I determine whether its the optispark unit or something else in the ignition system?
Drifting
Joined: Jul 2007
Posts: 1,294
Likes: 37
Don't waste your time elsewhere. . . its the Opti if you have no spark after a coolant bath....
I finally got to check spark and fuel.
I primed the fuel pump by turning the key to ON, and then poked the schrader valve with a screwdriver. Fuel shot out of it with a pretty good amount of force (not exacly scientific lol)
Then I had my dad turn it over while I checked for spark. I pulled a plug wire on the passenger side and tried to arc it while the engine was cranking, both on the exhaust manifold and the plug itself. Did on driver side next.
I couldn't get the plug wire to arc on anything while the engine was cranking, so there's no spark.
Now that I know it's a spark problem, how do I determine whether its the optispark unit or something else in the ignition system?
I primed the fuel pump by turning the key to ON, and then poked the schrader valve with a screwdriver. Fuel shot out of it with a pretty good amount of force (not exacly scientific lol)
Then I had my dad turn it over while I checked for spark. I pulled a plug wire on the passenger side and tried to arc it while the engine was cranking, both on the exhaust manifold and the plug itself. Did on driver side next.
I couldn't get the plug wire to arc on anything while the engine was cranking, so there's no spark.
Now that I know it's a spark problem, how do I determine whether its the optispark unit or something else in the ignition system?
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
first things first...............
1) see if you can jump a spark from your coil output to ground.
2) ICM. You can take your ICM to most auto parts stores and they can test it.
3) If #1 and #2 check out OK, then most likely your Opti...
...but as stated....the coolant bath most likely killed the Opti.
1) see if you can jump a spark from your coil output to ground.
2) ICM. You can take your ICM to most auto parts stores and they can test it.
3) If #1 and #2 check out OK, then most likely your Opti...
...but as stated....the coolant bath most likely killed the Opti.
Thread Starter
Intermediate
Joined: Aug 2004
Posts: 47
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From: Hartselle Alabama
ignition control module = icm? where is it located? sorry I'm not super familiar with the lt1 yet, this vette is my first chevy.
Are the optispark distributors from advance autoparts any good or should I order a GM one from the internet?
Are the optispark distributors from advance autoparts any good or should I order a GM one from the internet?
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas