1986 Engine Miss after it hits run temperature
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 40
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From: Abbottstown Pa.
1986 Engine Miss after it hits run temperature
Ever since I started driving after sitting most of the winter, my 86 begins misfiring once the engine reaches operating temperature. This started after a few fill-ups, and after dumping various liquids in the tank (moisture remover, Injector cleaner, sea foam ect) with no improvement.
So before I start checking the entire ignition and fuel system does anyone have any advice? Wires, plugs, distributor cap and rotor and coil appears good.
Thanks
So before I start checking the entire ignition and fuel system does anyone have any advice? Wires, plugs, distributor cap and rotor and coil appears good.
Thanks
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
The first thing I would check is to see if the car is going into Closed Loop at around 130 degrees..If it is, or isn't, let us know then we can help you from there.....WW
Last edited by WW7; Jun 11, 2015 at 02:03 PM.
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 40
Likes: 0
From: Abbottstown Pa.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
If you don't have your own scanner , Advance auto or Auto Zone can scan your car to see if it's going into close loop at around 130 degrees ..If it is going into closed loop, the scanner will show if your O2 sensor, and other sensors are working properly...Alot of times when a engine miss is temperture related like yours is, , it is a sensor not working properly causing the problem...WW
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
,the O2 sensor should be changed about every 30,000 miles or so, it should cost around $35.00 to replace...WW
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
How to check for closed loop mode:
Turn on ignition. <-- you MUST do this first
Short ALDL terminals A & B together.
Start engine.
The SES light will flash at 2-1/2 times per second in open loop mode and switch to flashing at once per second in closed loop mode.
Turn on ignition. <-- you MUST do this first
Short ALDL terminals A & B together.
Start engine.
The SES light will flash at 2-1/2 times per second in open loop mode and switch to flashing at once per second in closed loop mode.
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 40
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From: Abbottstown Pa.
Well I wasn’t sure that I could make it into the auto store to have their scanner check. So I had the great idea to re-set the computer. I disconnected the battery for 10 min. It starts right up but then dies. I can keep it running if I keep the peddle in it, but if I let off it stops. The lead plug is still in the idle adjusting screw so I don’t want to mess with it. Any advice?
86vetted
86vetted
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Race Director
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Well I wasn’t sure that I could make it into the auto store to have their scanner check. So I had the great idea to re-set the computer. I disconnected the battery for 10 min. It starts right up but then dies. I can keep it running if I keep the peddle in it, but if I let off it stops. The lead plug is still in the idle adjusting screw so I don’t want to mess with it. Any advice?
86vetted
86vetted
and the fuel filter?
Last edited by antfarmer2; Jun 13, 2015 at 10:34 AM.
Race Director
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Thread Starter
Intermediate
Joined: Oct 2007
Posts: 40
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From: Abbottstown Pa.
Good news, the problem I was having with the engine missing after warm up solved. Bad plug wire. Looking for suggestions for cut your own length kit? Then there was the problem with no idle. The tip of the IAC Valve fell off. The valve was replaced about 6 years ago, so why it decided to fall off now is a mystery to me. My Vette has 238,000 plus miles on it, ( I like to drive), so why it decided to unscrew now??? Thanks to all for the help.
Ed A
Ed A
Team Owner
Joined: May 2000
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From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
Since this Corvette needs a lot of work, to get it dependable car to drive, I would find a local Corvette Club to join, and more then likely had C4 at one time or another to ask questions and places to buy parts and knowledge about restoring your car, and venders that are reliable to shop.
