C4 after tune up problems
Thread Starter
Cruising
Joined: Jan 2023
Posts: 10
Likes: 1
From: New Bern NC
C4 after tune up problems
I just bought a 1993 40th anniversary edition convertible and I love it I decided to do a bit of an up grade on the motor because everything looked original and the car only has 69000 miles on it but still the parts looked 30 years old and I wanted to avoid a break down......Ok so I did the water pump (it had ball bearings missing) and I did the opti plugs wires and the coil Well it wasn't all that bad I got it all back together and started it up and it started first try lol ran for about a minute and died after that I couldn't get it to start The next morning I did the same thing it started then died again and would not start I'm feeling kind of stupid here it was running great before I made the improvements any help where to look for the problem
Pro
Joined: Jun 2018
Posts: 656
Likes: 239
From: Louisville, Ky
2022 C4 of the Year Finalist - Unmodified
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (appearance mods) 2019
My first suggestion is checking for fuel and spark. Simple check is spray some starting fluid (preferred) or carb cleaner in the throttle. If it starts it is most likely fuel. If not possibly spark and or both. Proceed from there.
HTH,
Joe K
HTH,
Joe K
Pro
Joined: Jun 2018
Posts: 656
Likes: 239
From: Louisville, Ky
2022 C4 of the Year Finalist - Unmodified
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (appearance mods) 2019
Sorry I'm not familiar enough with the LT1's to offer any other advice.
Joe K
Joe K
Melting Slicks
Joined: Jul 2003
Posts: 3,490
Likes: 868
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Always go back to where you started. If it ran good before, it might be you missed something. Anything get missed upon reassembly? Gotta be something basic like that. Re trace your steps
Thread Starter
Cruising
Joined: Jan 2023
Posts: 10
Likes: 1
From: New Bern NC
I have been doing that today and I look some stuff online and it could be I knocked some of the vacuum stuff lose I found a few lines that were old and no good anymore so Im working on that now
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Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
If you don't know that the opti that was in the car was actually causing problems ............. then I would sure consider putting the old opti back in and see if your "problem" is resolved. These days we pretty much stopped replacing the opti as a "long term maintenance item" unless it has actually been diagnosed as defective ...... due to the general unreliability of units currently being manufactured.
You may find this to be of some interest: https://petrisenterprises.com/blogs/tech-help
You may find this to be of some interest: https://petrisenterprises.com/blogs/tech-help
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Take the old opti-spark and replace the rotor and cap with MSD parts. They are the best. Also look into converting it over to a "vented" opti. Do a search, you should find out how. While you have it apart, gently clean the interior.
Melting Slicks
Joined: Jul 2005
Posts: 2,649
Likes: 863
If I understand your original post - you changed:
Plugs
Plug Wires
Ignition Coil
Optispark
Is that correct ??
If that is the case - I think the "new" opti is probably the most likely cause - but since it's a PITA to change - I would try changing back to the original Ignition Coil first. Did you take off the Coil Driver Module ? If so- did you use the appropriate heat transfer grease when re-installing ? And it can't hurt to check the resistance of the plug wires - particularly on the pass side where you can kinda - sorta get to them. One final question - where did you get the new spark plus from, there are supposedly lots of counterfeit spark plugs out there - so if you bought off a place like Flea-Bay or Amazon - you could have damn near anything in there for plugs.
Plugs
Plug Wires
Ignition Coil
Optispark
Is that correct ??
If that is the case - I think the "new" opti is probably the most likely cause - but since it's a PITA to change - I would try changing back to the original Ignition Coil first. Did you take off the Coil Driver Module ? If so- did you use the appropriate heat transfer grease when re-installing ? And it can't hurt to check the resistance of the plug wires - particularly on the pass side where you can kinda - sorta get to them. One final question - where did you get the new spark plus from, there are supposedly lots of counterfeit spark plugs out there - so if you bought off a place like Flea-Bay or Amazon - you could have damn near anything in there for plugs.
Thread Starter
Cruising
Joined: Jan 2023
Posts: 10
Likes: 1
From: New Bern NC
And the water pump lol ..............Thanks I will be heading out to the garage to start the process Thank God we have a leased honda civic to get to the auto part store .................and I don't even have to fix that one