Problem with 1986 Plymouth

Hello,

The four cylinder engine on my 1986 Plymouth Horizon either runs a little or runs backward a little bit when I shut the engine off. What is causing this? I have tried raising the octane of the fuel. I have also used a can of something I bought at an autoparts store that cuts carbon etc. from the engine and it did not stop the problem. The engine only has 46,000 miles on it. Can someone help me out here?

Thanks in advance for your help.

Thomas "Arkie" Hobbs

You need to post this in the Plymouth sections really, but other than that it sounds like maybe it's just idling too high? Have you just tried putting it in drive where the rpms will be a bit lower and shutting it off in gear? Not a permanent fix, but not as embarrassing as your engine dieseling 30 seconds after you shut it off in a parking lot. Actually, if it's a manual trans. then you can step on the brake with the clutch in, put it into gear, and with your foot on the brake still let out the clutch. Bam! Stops it cold. Jolts your car though too.

You need to post this in the Plymouth sections really, but other than that it sounds like maybe it's just idling too high? Have you just tried putting it in drive where the rpms will be a bit lower and shutting it off in gear? Not a permanent fix, but not as embarrassing as your engine dieseling 30 seconds after you shut it off in a parking lot. Actually, if it's a manual trans. then you can step on the brake with the clutch in, put it into gear, and with your foot on the brake still let out the clutch. Bam! Stops it cold. Jolts your car though too.

Thank you Deadlight.

Idling too fast is not the problem. Also, it doesn't diesel but a couple of seconds, but it shouldn't even do that.

Again, I thank you for your suggestions.

Thomas "Arkie" Hobbs

Shalom, Deadlight!

Hey! You were right after all! I took my 1987 Plymouth horizon in and they had to lower the base idle speed. It now shuts off fine.

Thanks you again for the suggestion.

Arkie

No problem man, glad I could help you out. :P