v6 runs backwards after key is turned off?

After I run my :v6: and it gets hot, I turn it off and it runs backwards a few rotations and sounds almost like a diesel. Why would it be doing this and how can I fix it? I'm pretty sure that it is an odd fire.

 

It is actually "dieseling". From Wikipedia:

http://en.wikipedia.org/wiki/Dieseling

 

:iagree:

 

VW bugs (and, I am sure, many other vehicles) had an electric solenoid in the idle circuit to cut off the fuel when the key was off just to prevent this issue. The "quick fix" for a bad solenoid was to nip off the end and reinstall it. The downside to this was an engine that dieseled every time you shut it off when warm...

 

I have the idle as low as it can go for crawling purposes. I can try backing the timing of a little though. I think what it needs is a good :smash:

 

Is it really running backwards or just self-detonating? (dieseling?)

You could fit an idle stop solenoid from a later car if you wanted. The ISS (aka anti-dieseling solenoid) allows you to close the throttle completely when the ignition is off.

Another solution is to just leave it in gear when you turn it off, and let the clutch out. It'll stop. See Lynn's post.

 

I hate to say it but it could also be caused by a vacuum leak
-carb base
- split PCV or vac hose
- butterflies in carb no closing fully
-etc

 

does that ISS mount forward of the throttle lincage on the manifold? I wondered what that thing was for.

 

Hmmmm... have lotsa ideas to try.

 

Typically it's on a bracket that goes under one of the carburetor base bolts.

 

sounds like engine run on to me (dieseling) as stated back the timing off a little. in most cases this is cause by carbon buildup in the cylinder, IT will get hot enough to Ignite the fuel when the key is turned off. with todays FI engines this does not happen because when you turn the key off you cut both the power to the Ign system and also the fuel system.

 

Also if the fuel mixture is too lean.

 

fuel, timing and cooling are all good. Still doing it. I'm starting to pop the clutch and hold the brake as an easy fix for now. It was run pretty hard and put away wet by the PO's. Maybe it just needs a rebuild?

 

When you go to shut it off make sure it is idling as low as possible before turning the key. Even if you have to blip the throttle to make sure it is on the idle cam as low as possible.

 

I fixed it! Kinda dumb luck they way I did. It was starting really hard so I decided to clean the plugs. The #6 plug was loose as a goose. With all of them clean and TIGHT, the engine was running like crap. I readjusted the carb and took for a long ride. No problems now!