vette won't start after mods
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,679
Likes: 1
From: South Amboy NJ
vette won't start after mods
93 lt1 auto - well guys and gals, after completing my heads, cam, intake, header, roller rocker blah blah blah swap, the car won't start. I turns over but it won't start. I hear the fuel pump go on and i smell gas after cranking but no go. the opti only goes on one way correct? (its got an idiot proof groove or whatever you want to call it, correct?)
any ideas or suggestions are greatly appreciated.
Dave
any ideas or suggestions are greatly appreciated.
Dave
Le Mans Master
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From: Jenison MI
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Cruise-In VII Veteran
St. Jude Donor '06
I guess would be that the rockers are to tight or you forgot to plug something in.
First make sure EVERYTHING is pluged in.
I forgot to plug in the sensor that sit infront of the rad one time and it would not start also the coolant sensor on the water pump, if that's not pluged in, it wont start.
Pull one plug out and check it for spark. If you have spark then you most likely have the rockers to tight or even worst the cam is not set right. That's my guess.
First make sure EVERYTHING is pluged in.
I forgot to plug in the sensor that sit infront of the rad one time and it would not start also the coolant sensor on the water pump, if that's not pluged in, it wont start.
Pull one plug out and check it for spark. If you have spark then you most likely have the rockers to tight or even worst the cam is not set right. That's my guess.
Safety Car
Joined: Jan 2001
Posts: 4,386
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From: Boise ID
I have zero experience with the Opti but if you’re not getting spark, I recall another forum member thinking he had it installed correctly (was speaking of the same groove) but the engine would not start. When he rechecked the Opti, it was found that it was not installed correctly. FWIW.
Race Director
Joined: May 2001
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Need to start with the basics, fuel and spark. You're getting fuel obviously. Check for spark. If you have spark then I would certainly double check the rocker adjustment. If everything was new it's very possible that the lifters were completely dry. Once they recieve some oil and pump up they'll hold the valves open too much.
If there is no spark make sure that all of your connections to the opti are secure. The factory service manual provides very good diagnostics that you can walk through to pinpoint the problem.
Also, try using the stock computer chip. Make sure the car will at least start with it before swapping to the custom chip I burned for you. If the chip is bad, or installed backwards you can pull your hair out trying to find the problem when it's just that simple.
If there is no spark make sure that all of your connections to the opti are secure. The factory service manual provides very good diagnostics that you can walk through to pinpoint the problem.
Also, try using the stock computer chip. Make sure the car will at least start with it before swapping to the custom chip I burned for you. If the chip is bad, or installed backwards you can pull your hair out trying to find the problem when it's just that simple.
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Before going to deep into it, stay with the basics as suggested above. Fuel and spark. A quick check with a noid light to see the ECM is pulsing the injectors IF you have fire at the plugs wouldn't hurt. If all that checks and no ECM codes, then it's probably mechanical.
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Le Mans Master
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From: Jenison MI
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St. Jude Donor '06
Originally Posted by 87SAM
I have zero experience with the Opti but if you’re not getting spark, I recall another forum member thinking he had it installed correctly (was speaking of the same groove) but the engine would not start. When he rechecked the Opti, it was found that it was not installed correctly. FWIW.
Judt do what Nathan says and work your way thru it. You may get lucky and find it right away. But most times it's the last thing that works
Race Director
Joined: May 2001
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Originally Posted by fsr402
But most times it's the last thing that works
"You find that problem yet?"
"Yeah but I'm still looking for it..."
Instructor
Joined: Jun 2001
Posts: 132
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From: Monroe Washington..the State
The number one reason I see early LT1 car for a no start is the opti not being splined correctly.
After some wear happens the shaft will spline in any of the locations being any where from one spline to 180* out.
Best way to check is with a mirror
A dead give away on this is that you have BOTH fuel AND spark but the car will not start
Good luck!
After some wear happens the shaft will spline in any of the locations being any where from one spline to 180* out.
Best way to check is with a mirror
A dead give away on this is that you have BOTH fuel AND spark but the car will not start
Good luck!
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,679
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From: South Amboy NJ
i have fuel and spark....checked the spark with one of those things you put on the plug and see the spark and checked the fuel with a guage (pressure was right according to the book)
how do i check the opti? stupid me put everything together including antifreeze and water and the only way i see of getting at it is to pull the wp.
how do i check the opti? stupid me put everything together including antifreeze and water and the only way i see of getting at it is to pull the wp.
Did you do this?
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,679
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From: South Amboy NJ
not yet...the springs are compressing and decompressing as the engine turns so i'm doubting they're overtightened...
i have a feelings its got to do with the opti/timing
when i was cranking it, a fireball came out of the intake...
i have a feelings its got to do with the opti/timing
when i was cranking it, a fireball came out of the intake...
Racer
Joined: May 2004
Posts: 476
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From: DFW TX
Originally Posted by BlackRoseLT1
not yet...the springs are compressing and decompressing as the engine turns so i'm doubting they're overtightened...
i have a feelings its got to do with the opti/timing
when i was cranking it, a fireball came out of the intake...
i have a feelings its got to do with the opti/timing
when i was cranking it, a fireball came out of the intake...
Le Mans Master
Joined: Jan 2003
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From: Portland Oregon
Originally Posted by BlackRoseLT1
will doing only one side help?...not looking forward to pulling that alternator support
how do i pump oil up?
how do i pump oil up?
The easiest way is to check compression first. If you have a rocker that is too tight there will be considerably less compression or no compression in that particular hole. However the fireball issue concerns me because that is a sign that the timing is waaaay out, and that means the perhaps the Opti is incorrectly indexed.