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Discussion Starter #1
Hi, I have a 1975 chev. Nova and I have noticed recently after turning the ignition key off the engine keeps running off for a second or two, I call it engine run off but I'm not sure if that is the correct term. It does not happen everytime but often enough to concern me. Any advice on the matter will be most appreciated. I will replace the timing gears soon, I wonder if this problem could be associated with timing gear problems, my car tends to reach a higher temp faster that it did before, particularly when going up hill. I'm giving details of the problems I'm having to give you and idea if all the problems are related with worn out timing gears, or else. Thanks for any help.
 

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I think you're talking about dieseling and it can be caused by a number of things; questionable gas too much timing,throttle not closing all the way,worn distributor (timing again), big time oil consumption even too hot a spark plug. My car recently had throttle cable stickiness that would allow it to run after I turned it off even in gear (automatic trans). It was some USA gas and the throttle not closing that caused it.
 

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I think you're talking about dieseling and it can be caused by a number of things; questionable gas too much timing,throttle not closing all the way,worn distributor (timing again), big time oil consumption even too hot a spark plug. My car recently had throttle cable stickiness that would allow it to run after I turned it off even in gear (automatic trans). It was some USA gas and the throttle not closing that caused it.
I agree also a bad vacuum hose can increase idle and cause this also. If your car has a secondary or high idle solenoid, make sure it's dropping off of that when key is turned off and it would fall back to the main idle. Also high idle on passenger side of carb for choke system as well.

Also it is referred to as "engine run on" or dieseling, just sayin is all.
 

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Discussion Starter #5
Thanks.

I think you're talking about dieseling and it can be caused by a number of things; questionable gas too much timing,throttle not closing all the way,worn distributor (timing again), big time oil consumption even too hot a spark plug. My car recently had throttle cable stickiness that would allow it to run after I turned it off even in gear (automatic trans). It was some USA gas and the throttle not closing that caused it.
Thanks for the advise, I believe too much timing could be part of the problem since I've had problems with the timing gears. I will move back the timing just slightly and see the results. This will be a guessing game since the numbers at this point are somewhat irrelevant. The timing #'s right now can not be rely on.
 

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Discussion Starter #6
I agree also a bad vacuum hose can increase idle and cause this also. If your car has a secondary or high idle solenoid, make sure it's dropping off of that when key is turned off and it would fall back to the main idle. Also high idle on passenger side of carb for choke system as well.

Also it is referred to as "engine run on" or dieseling, just sayin is all.
"Engine run on", instead of engine run off, I was somewhat close. Thanks for the correct terms and advice.
 

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I have the same problem with my kids falcon. I havent figured it out yet but was talking to a freind yesterday who said he solved the same problemon his car by drilling a small hole in the butterfly on the carb. Might work.
 

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I would try a higher octane gas. I had a 90 Olds Custom Cruiser and if I ran a lower octane gas and it would do the same as any of my Novas.:2cents:
 

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My new 383 did the same thing. I had the idle set around 900 rpm and the transfer slot was too exposed allowing too much fuel into the cylinders at idle. Once I backed the idle down to around 700 rpm it stopped. If you have a big cam you may actually have to increase the base timing to be able to get the idle lower without stalling.
 

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Discussion Starter #12
Thanks.

I have the same problem with my kids falcon. I havent figured it out yet but was talking to a freind yesterday who said he solved the same problemon his car by drilling a small hole in the butterfly on the carb. Might work.
I tried that even used octane booster. The problem has to do with timing issue. Timing gears have to be replace and some other work along with that.
 

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Discussion Starter #13
Thanks.

I have the same problem with my kids falcon. I havent figured it out yet but was talking to a freind yesterday who said he solved the same problemon his car by drilling a small hole in the butterfly on the carb. Might work.
It is never too late to say thanks.
 

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A friend of mine had this problem for about 4 months before his timming chain broke on start up one morning. After changing the timming chain it didnt do it anymore and ran better also.
 
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