Man I had my uncle do my tune up a few months ago bc I work alot. I had needed to replace my radiator and I finally did today. My 95 4.3 was sputtering trying to go to third and I finally checked my wires today. I had 3-4 spark plug wires loose man 🤦🏿♂️ I just had put some 3 inch super 44s on her a few months ago too and now I can hear how they really sound thanks to this video
If the car runs, you can bet the optispark is fine. If you look at how the wires are routed (through engine mounts and underneath the headers), tracing each wire to the correct cylinder can be really challenging. If the car *should* start or run well but doesn't and the wires and or plugs look new, it's a good chance some idiot (like me) replaced the wires in the wrong order. The best way to check this is from underneath the car, not from above - you can see much more of the ignition system from below.
I had a misfire in my 95 Impala and went through a similar diagnostic process to you where I started pulling spark plug wires checking for dead cylinders. Long story short, one of the wires going to fuel injector #2 was bad. Sometimes it would make a connection and the car would run fine and other times it wouldn't. I replaced the pigtail to injector #2 and that fixed it.
@@HilltownCT Indeed. I put all new ignition system, coil, wires, optispark, and 8 fuel injectors before I realized the problem. The intermittency is what had me stumped.
@@sstupidsstuff3453 Ouch! I had another issue I didn’t do a video on where I had a plug that was firing intermittently and it only manifested itself when the car was at operating temp. Guessing it was a heat expansion issue or something. Oh well, smooth sailing for now :-)
@@thastunna05 The IAC (idle air control) is near the coolant passage channel in the throttle body, and gets gummy sometimes. All those vacuum lines on the throttle body need to be checked, too. ua-cam.com/video/BvlUBl0aaMc/v-deo.html
Also, visual inspection of vacuum lines is maybe 10% effective vs. pulling them off and giving them an actual vacuum-hold test. On cars this old, chances are the vacuum lines are cracked, or are going to crack, anyway. Those hoses off the passenger side of the throttle body need periodic replacement. *If you use brake cleaner to check for vacuum leaks while the car is idling, make sure to have a CO2 fire extinguisher handy. That old grease mixed with solvent likes to burn long-time.
Nice video. I have a LT1 Corvette that, out of the blue, misfired, died, and I could hardly get it to start and run smooth. Wouldn't you know it happened away from home. Well, it finally ran alright getting home but after watching your video, I am going to save that hateful Optispark for last, if I have to change it. Sadly, I'm afraid to take the car anywhere until I sort this out. Thanks for your video.
On my Caprice it was the ign control module/coil. Sputtered and died, would crank but not start. Gave her some starting fluid and no change, leading me to start with ignition. Glad it wasn't the opti
I recently had someone change the spark plugs on my Chevy. Caprice didn’t have any symptoms of bad spark plugs just did it because I never done it before after we noticed backfiring engine, stalling, and engine has do you have any idea what this could be put the old spark plugs back and still doing the same thing backfiring from the Exaust engine installing and Car runs rough. Please help.
I have the same exact car and i had the same exact problem with my exhaust system now for sure I know what to look for god bless you partner keep on hogging 👍🏻 but its not a waste to change to new parts anyways that prolong its life 😁😁
Had the same trouble but I did what you did check the spark plug, solved the problem but the water pump went out so senes it was off I replaced the opti spark as well, one good thing about these cars if you take care of them they’ll run forever I’ve had mine for 18 years now. 95 caprice classic with the small block V8 they call them city sedans no need for a city employee to have a 5.7 lol
18 years…wow! I drive mine to work a couple times per week and it’s over 30 miles each way. It runs like a sewing machine and it’s more comfortable than my truck.
The problem is is that you took people's word that the optispark is usually the problem!! When it's NOT!!! The optispark is very simple to figure out if it's the problem or not!! If the optispark is actually going out then you'll get either a high resolution trouble code or low resolution trouble code!! The computer will tell you if it's bad!!! I can't stand listening to people always blaming the optispark!! I'll tell you right now that I've had a couple LT1 cars 4th gen camaro and currently a 92 corvette! I've never had an issue with the optispark on either one!!! But the corvette I changed out everything waterpump optispark belt and hoses just because I had no info on those parts so I went ahead and did some preventive work and putting the optispark back in I messed up the seal and in 3 months it filled with oil and crapped out! But that had nothing to do with the optispark!! I screwed up! So I re-did the optispark made sure the new seal was good and been running like a champ since!
my 96 c4 is misfiring in cylinder 5, i checked the wires, and when i pull it off i can hear the arc, and it has a new plug. so i replaced the injector, and it did not fix it, so i checked if it was getting fuel, and im pretty sure it is, but is still misfires at idle, low rpm low throttle, or high rpm high throttle. the only hope is adjusting the fuel trim, only codes are telling me to change the oil :( gonna get back into it again
Ever have a car with a weak spark on one cylinder? Got a Roadmaster, trying to find why it's bugging out. Thinking it has to be the Opti, right? But it's an expensive part to just be throwing at the car.
@@HilltownCT Swapped the wire, then the plug. Both known goods. Made no difference. Coil, O2s, and ign module are new, too. O2s solved the problem for a day. Just gonna buy the thing, methinks.
@@vitjuha96 Plenty more tests, but no real solution. The car is up on blocks basically being a test cow for anything I can come up with while I continue to put off changing the distributor. Partly because I'm also changing the oil pan and timing chain cover gaskets because the gaskets and seals are leaking pretty good. Wish I had a better answer, but that's where I'm at. Sorry, bud.
@@HilltownCT ok I'm buying a 94 this weekend died on the owner one day and he could never get it back running I already own a 91 and 96 so I'm excited to see what I can get going with this 94 it's a 9c1 also
@@hwyy9046 just went through hell with my 96 roadmaster! Put seafoam in one day and it bogged out on me after driving around for a while & wouldnt start back what so ever... after replacing opti, ignition coil, sensors, vac hoses etc, it came out to only be the ignition module -_- smh 😂 after all the wasted money it only took a $80 plastic module & it crunk up with ease 😎
@@bitchard215 I am also considering some tubular headers. I think a major reason to avoid it is that the plugs and wires are running really close to the manifolds. Zip ties or some nice cable looms can help keep the wires from touching the exhaust and melting/shorting.
Yeah, but I like this design because it makes people who aren't patient sell their cars for cheap. Once you have a good understanding of how to work on it, you have a reliable engine with a sound that makes you forget how angry you got when it broke.
Having this issue with my 96 Caprice with yr old plugs and wires. I was definitely thinking the worst but now I'll look here. Thanks!
Good luck…I hope you get off cheap!
Man I had my uncle do my tune up a few months ago bc I work alot. I had needed to replace my radiator and I finally did today. My 95 4.3 was sputtering trying to go to third and I finally checked my wires today. I had 3-4 spark plug wires loose man 🤦🏿♂️ I just had put some 3 inch super 44s on her a few months ago too and now I can hear how they really sound thanks to this video
Nice!
If the car runs, you can bet the optispark is fine.
If you look at how the wires are routed (through engine mounts and underneath the headers), tracing each wire to the correct cylinder can be really challenging. If the car *should* start or run well but doesn't and the wires and or plugs look new, it's a good chance some idiot (like me) replaced the wires in the wrong order. The best way to check this is from underneath the car, not from above - you can see much more of the ignition system from below.
The o-ring on mine was damaged, so it was probably a matter of time before it failed anyway. At least I’ll keep telling myself that.
Having the same issue! Lol… I changed mine.. and my arrogance got me thinking “IT CANT BE THE WIRES, THEY ARE NEW” 😟
I feel your pain :-)
I had a misfire in my 95 Impala and went through a similar diagnostic process to you where I started pulling spark plug wires checking for dead cylinders. Long story short, one of the wires going to fuel injector #2 was bad. Sometimes it would make a connection and the car would run fine and other times it wouldn't. I replaced the pigtail to injector #2 and that fixed it.
That’s interesting. When they run, they are phenomenal, but they seem to have their gremlins.
@@HilltownCT Indeed. I put all new ignition system, coil, wires, optispark, and 8 fuel injectors before I realized the problem. The intermittency is what had me stumped.
@@sstupidsstuff3453 Ouch! I had another issue I didn’t do a video on where I had a plug that was firing intermittently and it only manifested itself when the car was at operating temp. Guessing it was a heat expansion issue or something. Oh well, smooth sailing for now :-)
@@HilltownCTI have that issue now where it only does it at operating temp..temperature... what did you do???
@@thastunna05 The IAC (idle air control) is near the coolant passage channel in the throttle body, and gets gummy sometimes. All those vacuum lines on the throttle body need to be checked, too. ua-cam.com/video/BvlUBl0aaMc/v-deo.html
Also, visual inspection of vacuum lines is maybe 10% effective vs. pulling them off and giving them an actual vacuum-hold test. On cars this old, chances are the vacuum lines are cracked, or are going to crack, anyway. Those hoses off the passenger side of the throttle body need periodic replacement. *If you use brake cleaner to check for vacuum leaks while the car is idling, make sure to have a CO2 fire extinguisher handy. That old grease mixed with solvent likes to burn long-time.
Nice video. I have a LT1 Corvette that, out of the blue, misfired, died, and I could hardly get it to start and run smooth. Wouldn't you know it happened away from home. Well, it finally ran alright getting home but after watching your video, I am going to save that hateful Optispark for last, if I have to change it. Sadly, I'm afraid to take the car anywhere until I sort this out. Thanks for your video.
Thanks and good luck to you!
On my Caprice it was the ign control module/coil. Sputtered and died, would crank but not start. Gave her some starting fluid and no change, leading me to start with ignition. Glad it wasn't the opti
I recently had someone change the spark plugs on my Chevy. Caprice didn’t have any symptoms of bad spark plugs just did it because I never done it before after we noticed backfiring engine, stalling, and engine has do you have any idea what this could be put the old spark plugs back and still doing the same thing backfiring from the Exaust engine installing and Car runs rough. Please help.
I have the same exact car and i had the same exact problem with my exhaust system now for sure I know what to look for god bless you partner keep on hogging 👍🏻 but its not a waste to change to new parts anyways that prolong its life 😁😁
Thanks pal.
Had the same trouble but I did what you did check the spark plug, solved the problem but the water pump went out so senes it was off I replaced the opti spark as well, one good thing about these cars if you take care of them they’ll run forever I’ve had mine for 18 years now. 95 caprice classic with the small block V8 they call them city sedans no need for a city employee to have a 5.7 lol
18 years…wow! I drive mine to work a couple times per week and it’s over 30 miles each way. It runs like a sewing machine and it’s more comfortable than my truck.
Spark plug came loose!! Thanks man lol
The problem is is that you took people's word that the optispark is usually the problem!! When it's NOT!!! The optispark is very simple to figure out if it's the problem or not!! If the optispark is actually going out then you'll get either a high resolution trouble code or low resolution trouble code!! The computer will tell you if it's bad!!! I can't stand listening to people always blaming the optispark!! I'll tell you right now that I've had a couple LT1 cars 4th gen camaro and currently a 92 corvette! I've never had an issue with the optispark on either one!!! But the corvette I changed out everything waterpump optispark belt and hoses just because I had no info on those parts so I went ahead and did some preventive work and putting the optispark back in I messed up the seal and in 3 months it filled with oil and crapped out! But that had nothing to do with the optispark!! I screwed up! So I re-did the optispark made sure the new seal was good and been running like a champ since!
Thanks I'm currently having same issue guess what I did ordered opti spark and wires first
my 96 c4 is misfiring in cylinder 5, i checked the wires, and when i pull it off i can hear the arc, and it has a new plug. so i replaced the injector, and it did not fix it, so i checked if it was getting fuel, and im pretty sure it is, but is still misfires at idle, low rpm low throttle, or high rpm high throttle. the only hope is adjusting the fuel trim, only codes are telling me to change the oil :( gonna get back into it again
so apparently my brand new plug had a crack under the metal in the ceramic, and i could wiggle it just a bit. new plug in and misfire gone
Glad it was that simple. Miss my C4!
Ever have a car with a weak spark on one cylinder? Got a Roadmaster, trying to find why it's bugging out. Thinking it has to be the Opti, right? But it's an expensive part to just be throwing at the car.
Personally, I would swap a plug and wire from another cylinder and see if the problem moves. Go cheap first!
@@HilltownCT Swapped the wire, then the plug. Both known goods. Made no difference. Coil, O2s, and ign module are new, too. O2s solved the problem for a day. Just gonna buy the thing, methinks.
@@frikyouall any news? same shit there. New opti, coil, icm, plugs and wires...
@@vitjuha96 Plenty more tests, but no real solution. The car is up on blocks basically being a test cow for anything I can come up with while I continue to put off changing the distributor.
Partly because I'm also changing the oil pan and timing chain cover gaskets because the gaskets and seals are leaking pretty good.
Wish I had a better answer, but that's where I'm at. Sorry, bud.
That was smart 🌟
Love it.
My impala dies at idle at exactly 10 secs
It starts and drives fine but when i stop 10 secs later it'll die
It's a 94 and the opti isn't that old
Ever had issues of it cranking & not starting?
Yes, but only related to a bad fuel pump issue.
@@HilltownCT ok I'm buying a 94 this weekend died on the owner one day and he could never get it back running I already own a 91 and 96 so I'm excited to see what I can get going with this 94 it's a 9c1 also
@@hwyy9046 just went through hell with my 96 roadmaster! Put seafoam in one day and it bogged out on me after driving around for a while & wouldnt start back what so ever... after replacing opti, ignition coil, sensors, vac hoses etc, it came out to only be the ignition module -_- smh 😂 after all the wasted money it only took a $80 plastic module & it crunk up with ease 😎
@@low4oshow figured mine out it was just the coil
Mine turned out to be a threaded spark plug hole 😭
Hahahaha I'm happy I'm not the only person that's happened to
#6 wire did it for me 😆
Have the same issue on mines smh
Never get shorty headers. They are a misery.
To put on but why you think that?
@@bitchard215 I am also considering some tubular headers. I think a major reason to avoid it is that the plugs and wires are running really close to the manifolds.
Zip ties or some nice cable looms can help keep the wires from touching the exhaust and melting/shorting.
It's a stupid design by the way my opinion because you should never have the water pump flirting over the ignition system
Yeah, but I like this design because it makes people who aren't patient sell their cars for cheap. Once you have a good understanding of how to work on it, you have a reliable engine with a sound that makes you forget how angry you got when it broke.