when i turn off my truck sumtimes it kinda has trouble turning off

[infamouschevy]

85 Chevy c-10 OK hears the problem maybe sum one can help me so i have been driving the truck back and forth every weekend back and fourth like 400+ miles and the other day when i got home when i turned my truck off it didn't is like it wanted to stay on or more like a delay to turn off it didn't sound good is all i got say. so since then i has done it a few more times and sometimes does it worse then other times but its not frequent its random when it happens i wish i could explain what it sounded like better but maybe some one knows what im talking about

[oldredtruck]

 Check your timing - too much advance sounds like...

[Lt.Del]

did it just start doing this?  if so, are you getting fuel from a different station now?  If it was timing, it shouldn't just start happening unless you recently adjusted timing, or, you now have vacuum leak, which gives the intake too much air, like when you have throttle open. 

I hate dieseling.  Turn it off in Drive.  it won't diesel.  But, you still have to find cause.   Upping the octane will be temp. fix too, which is why i ask if you are getting different fuel.  Some cheap stations may not have true 87 octane.

[infamouschevy]

yes it did just start doing this recently after my 400 mile trips every weekend some 1 else had also told me it could be the timing. i asked a mechanic he said to change the fuel pump and the fuel filter. so i think I'm going to try that  and see what happens. but THANKS FOR THE HELP I'm not to engine savvy. 

[VileZambonie]

Some mechanic 

check your choke and your idle speed first.

[81C20]

High idle speed, incorrect timing, rich mixture, or shutting it down right after a hard run will cause dieseling. Fuel pump and filter will not cause this, at the very most a restricted fuel filter will cause a lean condition and lack of power.

[Lt.Del]

fuel pump/filter causing dieseling?   Find a new mechanic.

If it happened suddenly, i'd say a vacuum line popped off letting too much air in the manifold.  However, ensure your hold down bolt to distributor is not loose....if so, the distr. could have moved--check timing.

[1980c10]

you could check idle speed, check the timing since it is easy. then maybe a tune up and a compression check would also be a good idea and what everyone else said.

[Stewart G Griffin]

Also check to see if the throttle springs are returning the throttle all the way closed when you let off of the pedal.  The spring may have weakened over time.

This is what happened to me--the engine would diesel for a few secs after i shut it off.  The spring were not closing the throttle all the way.

[eventhorizon66]

Same thing was happening with my truck a long time ago.  Man was that embarrasing.  Replaced the choke cap/coil/thermostat (what ever you want to call it) and that fixed it.  If there was problem with your fuel delivery system it would have trouble running, not trouble shutting off.

[kurtdirt1]

Same thing was happening to me with my truck. I'd shut it off and the dang truck wanted to keep running (real ugly sounding and quite embarrassing) Pull your dist cap. Mine ended up being toasted inside. Replaced the cap and rotor and all is fine now.

[k5blazerfan]

mechanic sounds like an idiot... check for vaccumm leaks and make sure your getting good spark and that you have proper gas and air fuel mixture.... i would seafoam it and get all that cheap gas carbon out of it

[kurtdirt1]

Same thing was happening to me with my truck. I'd shut it off and the dang truck wanted to keep running (real ugly sounding and quite embarrassing) Pull your dist cap. Mine ended up being toasted inside. Replaced the cap and rotor and all is fine now.

Actually what I did didn't cure it. It's doing it intermittently again Darn'it!! I was talking to my dad and he suggested that there was something in the column, some kind of metal bar that may be bad? Anybody know what he's referring to?

[Lt.Del]

With all respect, I don't believe your dad is correct.

Try what i suggested earlier, turn it off while the truck is still in Drive.  That'll tell you if the ignition switch is working correctly--if it kills the current and turn the truck off. 

The tips listed on this thread is what it must be...vacuum leak allowing too much air in, misadjusted idle and / or choke, bad gas.  Put some high octane in it for a tank and see if that corrects it....i bet it does...but that is a temp. fix. 

ARe your spark plugs kind of new?  If they are too hot for your truck, it will continue to detonate after turned off as well.       

[1980c10]

You could slightly retard your ignition timing a little, then try it out. Ultimitatley your problem is too hot of a spark or other hot spot in a cylinder, timing or too much fuel which of these suggestions fall under except what your mechanic has told you. it is a problem common problem with many causes, probably an easy fix as soon as you find it.