Optispark Install Help! Timing/backfiring
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Cruising
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Optispark Install Help! Timing/backfiring
(Fyi I a huge noob when it comes to cars, enlighten me! Im trying to learn as much as I can!)
I have a 94' corvette and I am trying to install a vacuumed optispark.
So I've installed a new msd cap and rotor for the distributor and have also replaced the spark plugs and plug plug wires. I've read through several forums and I am at a lost. I try to start the car and all it does is backfire. I've been told that the spark plug wires are messed up
I used this diagram for wiring the spark plug wires. I assume its the same since its the same engine(but on an f-body)
I've tripled checked and quadruple check the wires but it doesnt seem to work. Could it be because of the damper/balancer? When unscrewing the bolts, the damper was turned as well. Could that be the problem?
I have a 94' corvette and I am trying to install a vacuumed optispark.
So I've installed a new msd cap and rotor for the distributor and have also replaced the spark plugs and plug plug wires. I've read through several forums and I am at a lost. I try to start the car and all it does is backfire. I've been told that the spark plug wires are messed up
I used this diagram for wiring the spark plug wires. I assume its the same since its the same engine(but on an f-body)
I've tripled checked and quadruple check the wires but it doesnt seem to work. Could it be because of the damper/balancer? When unscrewing the bolts, the damper was turned as well. Could that be the problem?
Last edited by CarNuub; Jul 19, 2009 at 08:12 PM.
Race Director
Joined: Jan 2002
Posts: 12,263
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From: O'Fallon Missouri
There is only one way for it to align, but it can be forced in. If you look at the splined shaft there is a flat spot that has to align with the flat spot in the timing gear. The opti should slide into place with very little effort.
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
Backfiring is caused by spark at the wrong time. A spark with the intake valve open makes the fuel/air in the intake system explode. If you have plug wires on the wrong spark plugs, backfiring can occur. You have a good guide as to the plug wiring, so I doubt that is your problem. If you haven't taken the opti off the car, then shaft misalignment shouldn't be the problem. Check again for the proper installation of the cap and rotor and their indexing. Do you have the old cap and rotor? Try installing them and see if you still have problems. Use a timing light to see if you have proper timing while cranking, I'll bet a big bunch of money you don't.
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Cruising
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Drifting
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From: Chicago Executive Airport, formerly known as Palwaukee
No-IL Events Coordinator
St. Jude Donor '12-'13-'14-'15-'16-'17
One cannot adjust the timing on an LT1 or LT4. The timing is set by the Optispark in conjunction with the Powertrain Control Module (PCM).
The Optispark distributor HAS to be aligned perfectly to work.
Follow all of your spark plug wires (perhaps have a friend help with this) from the distributor to the individual spark plugs.
I have a feeling you have 2 or 4 wires crossed. That would account for your backfiring and lack of starting.
Save the Wave!
The Optispark distributor HAS to be aligned perfectly to work.
Follow all of your spark plug wires (perhaps have a friend help with this) from the distributor to the individual spark plugs.
I have a feeling you have 2 or 4 wires crossed. That would account for your backfiring and lack of starting.
Save the Wave!
Thread Starter
Cruising
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I'll try and re-check the wires again. After the 5th time =[
I've only changed the cap and rotor, it should be the same as before. Is it possible for it to backfire if one of the spark plug wires is loose?
I've only changed the cap and rotor, it should be the same as before. Is it possible for it to backfire if one of the spark plug wires is loose?
Drifting
Joined: May 2005
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From: Chicago Executive Airport, formerly known as Palwaukee
No-IL Events Coordinator
St. Jude Donor '12-'13-'14-'15-'16-'17
Your 1st post said you were installing a vacuumed Optispark.
Now you say you only replaced cap and rotor.
Which one is it?
If the original distributor was not off the engine, then you would not have to reinstall it.
I am
!
If any of the spark plug wires is loose, there will be backfiring and miss firing.
Save the Wave!
Now you say you only replaced cap and rotor.
Which one is it?
If the original distributor was not off the engine, then you would not have to reinstall it.
I am
!If any of the spark plug wires is loose, there will be backfiring and miss firing.
Save the Wave!
Thread Starter
Cruising
Joined: Jul 2009
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Your 1st post said you were installing a vacuumed Optispark.
Now you say you only replaced cap and rotor.
Which one is it?
If the original distributor was not off the engine, then you would not have to reinstall it.
I am!
If any of the spark plug wires is loose, there will be backfiring and miss firing.
Save the Wave!
Now you say you only replaced cap and rotor.
Which one is it?
If the original distributor was not off the engine, then you would not have to reinstall it.
I am
!If any of the spark plug wires is loose, there will be backfiring and miss firing.
Save the Wave!
I did take original distributor off and changed that cap and rotor.
I have a feeling I just screwed myself.. =[
Drifting
Joined: May 2005
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From: Chicago Executive Airport, formerly known as Palwaukee
No-IL Events Coordinator
St. Jude Donor '12-'13-'14-'15-'16-'17
If the ignition wires are installed correctly, then the only thing that comes to mind is the installation of the Optispark itself.
As a previous poster said, it will install incorrectly with just a slight nudge.
Compared to just sliding on easily if placed correctly.
Don't beat yourself up. We all have made our fair share of mistakes. Some of us just don't like to own up to them!
Save the Wave!
As a previous poster said, it will install incorrectly with just a slight nudge.
Compared to just sliding on easily if placed correctly.
Don't beat yourself up. We all have made our fair share of mistakes. Some of us just don't like to own up to them!
Save the Wave!
Thread Starter
Cruising
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Thanks everyone for your help. You have no idea how hard it is to find people who actually know a thing or too. I'll re-check the spark plug wires, maybe I might have made a mistake while labeling the wires. Hopefully, I just made a mistake, I dont want to pay people ridiculous amounts of money to fix my car.
Drifting
Joined: May 2005
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From: Chicago Executive Airport, formerly known as Palwaukee
No-IL Events Coordinator
St. Jude Donor '12-'13-'14-'15-'16-'17
You are very welcome!!!
You did not say you labeled the wires. Oh.............that would be all it would take. A little mislabeling here, a little mislabeling there, and all of a sudden...........kapow!!!
I am going to bet you have several wires crossed. Also, I hope you don't have to take that blasted distributor off again!
We have all been there, done that. I am just happy we can give you a little guidance so you can get where you want to go!
Save the Wave!
You did not say you labeled the wires. Oh.............that would be all it would take. A little mislabeling here, a little mislabeling there, and all of a sudden...........kapow!!!
I am going to bet you have several wires crossed. Also, I hope you don't have to take that blasted distributor off again!
We have all been there, done that. I am just happy we can give you a little guidance so you can get where you want to go!
Save the Wave!
Thread Starter
Cruising
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Ok soo I've checked that I've plugged all the wires in the correct order. I've changed out the rotor and cap to the originals. And no go. What the eff.
The only thing I havent checked is the connections at the spark plugs. I was certain I've put them in correctly and firmly. Does the pulley effect the timing? (I might have said balancer/damper)
The only thing I havent checked is the connections at the spark plugs. I was certain I've put them in correctly and firmly. Does the pulley effect the timing? (I might have said balancer/damper)
Race Director
Joined: Jan 2002
Posts: 12,263
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From: O'Fallon Missouri
The pulley does not affect timing. Pull the opti back off and install it correctly. Also, before you put the water pump back on, breifly start the car just to make sure the opti is installed correctly this time.
Thread Starter
Cruising
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Yeah, I've read a few forums and they said to try starting the car before putting in the water pump so I've been doing that from the start. I'll inspect the shaft to make sure the opti is correctly positioned but I know for sure its right since, I've pulled out the opti at least 6 times today.