Hi Rick, ’74 Challenger. I’m running a
440 with 4-Bbl, dual-plane intake, Eddie
heads, TTi headers, 3″ exhaust, and a
0.509” purple-shaft in some really hot summer
weather right now. I have replaced my
180-degree thermostat with a 190 and found
that it runs on after I shut the car off. Would
you recommend a 160-degree thermostat in
this hot hot weather to alleviate this issue?
If the weather is really hot, the
thermostat just sets a minimum coolant
stop solenoid. When you turned off the
ignition, the solenoid powered down,
snapping the throttle almost completely
shut. No air = no dieseling.
temperature point and has no effect on actual operating temperatures. So, no. Ideas: First, be sure you have adequate fuel octane. Reduce idle RPM to minimum
acceptable. Then look at something like the factory did: An idle stop solenoid (see pix above, it can’t diesel if there’s
no airflow). Cold air induction also helps. Lastly, shut it off in gear (or stall it w/clutch if M.T.)