67MustangJDM

Ive got a 67 200ci auto that most of the time when I turn it off, the engine shakes and then sounds like something is releasing pressure then you smell this weird smell after it finally shuts down... Like oil or gas smell maybe. So this only happens sometimes not all the time and the "process" starts right as I turn the key to off and it lasts a second or two. It seems to be totally random as to when this happens too, any ideas? Do you think it could be dieseling? Or could it be me using regular gas?

1slow67

does it act like it wants to stay running? If so your idle is too high.

racin66coupe

yeah, idle is set too high, any idea of what its set at? it should be under 1000 rpm. around 600ish

67MustangJDM

No the idle is set in a good spot, so its something else... Just what! Hahaha
The car doesnt seem to want to keep running, the engine just starts to shake and then there is that pressure release-ish sound then its off. It only happens occasionally so it doesnt happen every time its totally random.

67mustang302

What's the ignition timing?

67MustangJDM

Hey guys, well today I turned my car off and it did this longer than its ever done... like 4-5 seconds. But this time, since it was so long for me to hear it for once, it sounded like the engine was still firing but struggling to do so, really struggling... enough to shake the car. Do you think the carb isn't closing and still letting in air/gas in?

1slow67

Mine does that every so often. Engine is at too high of an idle when you turn it off. All 3 of my carbs have done this.

racin66coupe

do you have a tach set up?

67MustangJDM

No I dont. Ive just used a portable one to check it. I want to add one tho!