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#1 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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motor turns over a couple more times after shut off?
this happens about once every couple times I drive it. when I turn the key off, the truck turns over a couple more times like its tryin to stay on and then dies. what is this from?
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#2 |
Registered User
Join Date: Jun 2013
Location: billings, mt
Posts: 703
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Re: motor turns over a couple more times after shut off?
far as I know it's usually cause the timing is slightly off. mine's doing it now as well just haven't had a chance to put a timing light on it.
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1969 Chevy C10 2wd stepside longbox |
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#3 |
Registered User
Join Date: Jan 2011
Location: Townsend MT
Posts: 1,725
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Re: motor turns over a couple more times after shut off?
How could timing affect it? as soon as the key is shut off, there is no spark to be timed.
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#4 |
Registered User
![]() Join Date: Jul 2012
Location: White Salmon, WA
Posts: 263
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Re: motor turns over a couple more times after shut off?
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#5 |
Registered User
Join Date: Dec 1999
Location: Mississippi
Posts: 119
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Re: motor turns over a couple more times after shut off?
the term for it is dieseling, also known as engine run-on. you can google it and find gobs of info.
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1970 GMC Custom 1500 SWB 307/TH350 3.73 Positrac |
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#6 |
Senior Member
![]() Join Date: Mar 2003
Location: Colfax-California
Posts: 8,553
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Re: motor turns over a couple more times after shut off?
Timing cranked up too high, vacuum leak, idle adjusted too high.....
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#7 |
Registered User
Join Date: Jun 2010
Location: Upland Ca
Posts: 4,143
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Re: motor turns over a couple more times after shut off?
Run-on is almost always cause by the idle being to high.
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1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703 |
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#8 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
The truck bogs when I stomp it from a idle, could this be related? once it gets past the bog it runs like a raped ape
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#9 | |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: motor turns over a couple more times after shut off?
Quote:
In the past when I've had dieseling problems, I always throw in one or two cans of fuel treatment like Chevron. I usually do it every fill up until it stops. Had good luck like that. I had to do it on my Ranger work truck three times and haven't had any problems for 3, 4 years.
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68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
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#10 |
Registered User
![]() Join Date: Apr 2014
Location: Galivants ferry, South Carolina
Posts: 189
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Re: motor turns over a couple more times after shut off?
It's your timing sounds like to me
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#11 |
Registered User
Join Date: Jun 2013
Location: billings, mt
Posts: 703
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Re: motor turns over a couple more times after shut off?
got my timing sorted out tonight (and found my vacuum advance no longer functions) but the dieseling stopped. the distributer was a little loose and moved itself to about 20deg set it back to 10
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1969 Chevy C10 2wd stepside longbox |
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#12 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
i dont have a timing light....ill have to find someone who does
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#13 | |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: motor turns over a couple more times after shut off?
Quote:
I find it always a hassle to borrow tools since these days most people don't do their own work on these new vehicles. And, if money is tight, buy one at a time.
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68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
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#14 |
Registered User
![]() Join Date: Jul 2012
Location: White Salmon, WA
Posts: 263
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Re: motor turns over a couple more times after shut off?
Dieseling and bog into transition is definetly idle set too high, opening the blades into the transition slot. Timing does not effect engine run.
More initial timing will allow you to bring the idle back to where it belongs. More intial timing will also allow the idle to burn better keeping the heads cooler if that is the issue but not likely since you also mention the bog. |
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#15 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
so what is "more initial timing"? ive always had EFI hot rods so I dont understand this. I adjusted the timing in my blown mustang with a switch in the glove box for race fuel
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#16 |
Registered User
![]() Join Date: Jul 2012
Location: White Salmon, WA
Posts: 263
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Re: motor turns over a couple more times after shut off?
You need a timing light. Check timing with engine at operating temp and disconnect distributor advance from vacuum hose (plug hose from carb). This is your initial timing.
You could just try rotating distributor about an 1/8" counter clockwise, which will then raise your idle. Now lower the idle back down at the carb with idle screw. See how she acts with this adjustment. If starter drags, it's too much counter clock rotation. |
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#17 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
which one is the idle screw?
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#18 |
Registered User
![]() Join Date: Jul 2012
Location: White Salmon, WA
Posts: 263
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Re: motor turns over a couple more times after shut off?
You being serious? As in which screw in the engine bay? Have you looked at your carburetor? At the end of the throttle(gas pedal) rod, there's a lever and a screw attached to that, back it off to lower idle. Go as low as you can run it with an auto transmission in gear. This is all a bit DIY, and if you're not comfortable in that area you may want to find someone that is. Though I have never found any competent mechanics that can do more than read an OBD port.
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#19 | |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
![]() Quote:
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#20 |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: motor turns over a couple more times after shut off?
Depends on the carb you have. A pic would help.
The idle speed screw is the one that increases or decreases the idle speed on the engine. Idle air screws are the ones usually at the base front of carb and are used to adjust the idle air mixture for maximum vacuum.
__________________
68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
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#21 |
Registered User
Join Date: May 2014
Location: Sacramento CA
Posts: 60
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Re: motor turns over a couple more times after shut off?
its an edelbrock 600 electric choke. ill give this a try and see how it goes
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#22 |
Registered User
Join Date: Jun 2010
Location: Upland Ca
Posts: 4,143
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Re: motor turns over a couple more times after shut off?
Your next purchase needs to be a service manual.
__________________
1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703 |
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#23 |
Senior Member
![]() ![]() Join Date: Sep 2008
Location: Harrison, Arkansas
Posts: 9,815
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Re: motor turns over a couple more times after shut off?
Hang in there Matty. I've been working on these things for fifty years and still have to ask what screw from time to time? I'd say everybody on this board has had the "dieseling" problem at one time or another, and it can be hard to sort out. It's usually a combination of things, and ethanol doesn't help.
As said before, vacuum, idle air settings, idle speed, and timing. Lots of combinations, and a lot of it is by ear.
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other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless. |
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