60 Won't Idle, and "dieseling" upon shut down

Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
After an extensive rebuild of most things in the engine bay: head, carb, IM, P/S, A/C, cooling system, etc. I am still in the first 500-1000 miles or so of shakedown from having everything reassembled.

Two weeks ago I made it about 65 miles on a 100 mile trip before overheating. I was cruising on the freeway, above 3K rpm, pulled off the freeway to get gas and when I did the temp gauge went into the red. As I rolled into the gas station and shut it off, coolant started bursting from the water pump (the one part of the coolant system I did not replace last year).

I towed it home and ordered parts. Installed everything this morning, filled it with coolant/water and it started right up and idled. Temp gauge stayed at 1/4 at idle. Went for a drive and temp gauge went to 3/4 and stayed there, going slightly up when stopped and down to 3/4 when cruising. I stopped at the market and upon shut off it dieseled for a few seconds.

Started right up and idled no problem. I ran it a bit hard on the way home to put it through its paces, and let it idle for a few minutes when I got back home. Temp gauge went up close to red, but never met the line and stayed there. When I shut it off it dieseled again. Engine was definitely hot, I could hear what sounded like water boiling, and the overflow tank filled up and was spitting coolant.

I set the front end up and let it cool. Once cooled, the overflow was now empty. I filled more coolant while pumping the upper rad hose until all the air was gone. It started right up, but will not idle. Tried it with choke, no choke. It won't idle.

That is where I am at.
 
Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
UPDATE: with just letting it sit, it's now idling.

Coolant temp is still getting up there while cruising around town, stop and go. It went up as high as 80-90% to the red while idling in front of the house after driving. I shut it down and it's still dieseling.
 

OSS

Joined
Jun 30, 2017
Messages
3,685
Location
Oblivion
Visit site
Replace the fan clutch of its old.
Replace the radiator if it's old.
Replace the radiator cap.
Test the functioning of the Fuel Cut Solenoid in the carb (procedures in the emissions manual).

Once the 2F cooling system boils, a lot of air gets trapped in the head and it can take weeks of regular driving to purge it all out. Until then - the gauge will show hotter than normal.
 
Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
Thanks OSS

I went back out yesterday and it won't hold idle again.

Is your suggestion to test the Fuel Cut solenoid related to the idle and dieseling issues?
 

OSS

Joined
Jun 30, 2017
Messages
3,685
Location
Oblivion
Visit site
If the FCS doesn't turn on, the carb will be starved of fuel at idle. If the FCS is stuck in the ON position, the engine will diesel when shutting down.
You have both symptoms but can't have both causes - so check out the function of the FCS to rule it out.
 
Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
If the FCS doesn't turn on, the carb will be starved of fuel at idle. If the FCS is stuck in the ON position, the engine will diesel when shutting down.
You have both symptoms but can't have both causes - so check out the function of the FCS to rule it out.
Will do. I checked it within the last 500-1000 miles and it was good then, but I'll check it again.
 
Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
Will do. I checked it within the last 500-1000 miles and it was good then, but I'll check it again.
FCS is functioning properly, and there is continuity in the switch when engine is off.

Now at a consistent point where it will not idle. Not sure what to check next.

Also, my choke cable get's stuck in the pulled position. it's like the cable isn't slipping through the line smoothly.
 
Joined
Feb 22, 2016
Messages
98
Location
Venice, CA
Visit site
Have you checked the timing? Dieseling and overheating sounds like the dizzy may be too advanced.
I have not checking timing, but timing was set prior to overheating and it was running well until that. All I have done is replace the water pump and alternator. So unless one of those things messes with timing, I don't see why timing would be off now.

Took a drive this morning. It idles fine once I get it going, it's only on initial start up that it won't idle. And it is still dieseling upon shut off.
 

Users who are viewing this thread

Top Bottom