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Topic: Just bought 1986 Base C4 with 3700 miles starts runs then.....

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Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 1/15/24 7:56am Message 11 of 21
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Sun City Center, FL - USA
Joined: 12/22/2023
Posts: 7
Vette(s): 1986 Corvette white convertible

Hey! - THanks for your suggestions!  It's so frustrating as it happens EVERYTIME it hits about 178-180 degrees. Shut off - let it sit - fires right back up.  Will look into the fuel pump suggestions!  Enjoy your Vette!

 




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Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 1/30/24 2:17am Message 12 of 21
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Williamsburg, OH - USA
Joined: 11/11/2019
Posts: 16
Vette(s): 1985 light blue metallic bone stock 4+3 coup

 

 



|UPDATED|1/30/2024 2:17:50 AM (AZT)|/UPDATED|



Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 2/7/24 10:43am Message 13 of 21
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Caldwell, ID - USA
Joined: 11/26/2017
Posts: 6
Vette(s): Black 1987 Corvette Engine-383, 450 HP. Transmission- 700R4 with shift kit and 2300-2500 monster torque converter Wheels- 9 1/2 front, 11" rear.

Just use a magnet, won't stick to aluminum.




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 2/21/24 2:26pm Message 14 of 21
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Battle Creek, MI - USA
Joined: 2/10/2024
Posts: 1
Vette(s): 1993 40th Anniversary Corvette, 6 Speed, Ruby Red

That sounds like the problem I had with my ‘93 but it is li  oh ely something else. The 93 cars have bad distributors which often need to be replaced. Just in case, has someone checked your distributor?




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 3/6/24 9:30am Message 15 of 21
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beaufort, SC - USA
Joined: 9/1/2009
Posts: 39
Vette(s): 1990 Turquoise Corvette (his) & 1990 Turquoise Corvette (hers)indy festiville car for sale

Check the idle control valve and clean the throttle body




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 3/6/24 11:14am Message 16 of 21
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Sun City Center, FL - USA
Joined: 12/22/2023
Posts: 7
Vette(s): 1986 Corvette white convertible

Hello and thanks for your suggestion - turns out - the company I ordered a refurbished ECM did NOT program it correctly  - have been able to get it to run just fine and now doesnt stall out - however, it is still not programmed correctly!  The Service Engine Light stays on all the time!   So - time to remove the entire ECM AGAIN - hopefully this time the unit WILL be propertly reprogrammed.. soon!




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 5/4/24 7:24pm Message 17 of 21
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Joined: 7/3/2011
Posts: 16
Vette(s): 1991 corvette convertible, yellow in color, black interior with a 6 speed tranny..

Good Day,

Congratulations on your new ride.  Buying a classic car that has sat for some time do need some TLC to get it up to peak performance.  All the other members have made some very good advice.   I have taken care of a private car collection for some time and I would recommend changing all the motor fluids and the drivetrain oils.   The Anti freeze is often forgotten but it is important due to the rust inhibitors that break down over time and no longer provide protection and that starts to deteriorate the seals and gaskets.  The C4 Corvette is real easy to change the in tank fuel pump and completely remove all the old gas.  There are lots of you tube videos that can guide you.  The fuel injectors in the L98 motors are very sensitive to harsh fuel cleaners so be careful how much you mix in the fuel.  The injectors have coated wires inside and the fuel washes over these wires and disks and if too harsh a chemical will deteriorate the wire coating and the fuel injector will fail.  I learned this the hard way on my personal car.  Changing the injectors on a tuned port injected car is quite involved and will be a 2 day project.  

Once you get all the maintenance done these cars are very reliable and a blast to drive.   Save the wave and enjoy!!  




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 5/4/24 7:24pm Message 18 of 21
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Joined: 7/3/2011
Posts: 16
Vette(s): 1991 corvette convertible, yellow in color, black interior with a 6 speed tranny..

Good Day,

Congratulations on your new ride.  Buying a classic car that has sat for some time do need some TLC to get it up to peak performance.  All the other members have made some very good advice.   I have taken care of a private car collection for some time and I would recommend changing all the motor fluids and the drivetrain oils.   The Anti freeze is often forgotten but it is important due to the rust inhibitors that break down over time and no longer provide protection and that starts to deteriorate the seals and gaskets.  The C4 Corvette is real easy to change the in tank fuel pump and completely remove all the old gas.  There are lots of you tube videos that can guide you.  The fuel injectors in the L98 motors are very sensitive to harsh fuel cleaners so be careful how much you mix in the fuel.  The injectors have coated wires inside and the fuel washes over these wires and disks and if too harsh a chemical will deteriorate the wire coating and the fuel injector will fail.  I learned this the hard way on my personal car.  Changing the injectors on a tuned port injected car is quite involved and will be a 2 day project.  

Once you get all the maintenance done these cars are very reliable and a blast to drive.   Save the wave and enjoy!!  




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 5/24/24 8:16am Message 19 of 21
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Joined: 4/11/2024
Posts: 1
Vette(s): 1994 Vette

I had a slightly similar problem with my 94; the previous owner only drove the car about 500 miles a year.  My car was hard to start especially when the engine was near operating temp, but it seemed to run great otherwise.  I replaced several sensors to no avail.  I took it to a REAL mechanic, and he solved my issue in no time flat.  The problem was the fuel pump.  In retrospect, I think the pump may have been compromised due to the prevalence of the corn oil or whatever they toss in gasoline now-a days.  I am not saying that the fuel pump is the issue; it might be the carb.  

 

Bob




Re: Just bought 1986 Base C4 with 3700 miles starts runs then.....

Posted: 5/29/24 1:38pm Message 20 of 21
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beaufort, SC - USA
Joined: 9/1/2009
Posts: 39
Vette(s): 1990 Turquoise Corvette (his) & 1990 Turquoise Corvette (hers)indy festiville car for sale

Try the idle control valve 




in Forum: C4 Engines


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