Leila (72 f) likes to diesel and spit when we shut her off. Is that a timing thing?
"diesel" doctor wanted
- Thread starter frobuster
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1911
chupacabra
Do you have a Fuel Cut Solenoid? Can't remember if they had those in '72 or not. The FCS if present and functioning should prevent dieseling. But the most common cause of dieseling in older gasoline engines is carbon build-up in the head.
alia176
SILVER Star
did you give her an "italian" tuneup yet? That may help clear out the carbon.
- Thread starter
- #4
I have "heard" about that, I'm scared to death to try it though; could that total an engine? ie put a hole in a piston or pop one off of its rod? Any volunteers? I'll supply the shotglass and ear plugs.
alia176
SILVER Star
Also, another old remedy to clean off carbon off the piston tops:
get her nice and hot and suck in a "LITTLE" bit of water through a vacuum hose to steam clean the piston tops. I said a LITTLE, not suck the water bottle dry. I do this about once a year to all of my vehicles. You can also use Sea Foam Green to do the same thing.
get her nice and hot and suck in a "LITTLE" bit of water through a vacuum hose to steam clean the piston tops. I said a LITTLE, not suck the water bottle dry. I do this about once a year to all of my vehicles. You can also use Sea Foam Green to do the same thing.
My '70 did not have a fuel-cut - 72 in stock form should be the same. Once the ignition switch is shut off there should be no souce of ignition in the chamber except excess carbon sizzling away. Dr. Whately's "diesel in the oil" thing was supposed to help that too in addition to ungooping the rings.
Only other thing I've heard of is running a plug in a heat range that retains too much post-shutoff heat with a carb that leaks gas into to manifold somehow.
I never understood the timing aspect because no spark = no timing influence. Good luck.
Only other thing I've heard of is running a plug in a heat range that retains too much post-shutoff heat with a carb that leaks gas into to manifold somehow.
I never understood the timing aspect because no spark = no timing influence. Good luck.
I think the timing aspect has to do with the carbon buildup.
the fuel shutoff solenoid has been used since the 60s on the carbs. Maybe some didn't have them, but SOR lists one for all years. I know I had one on an early one-barrell (the round window does, square window doesn't) and also on my '77 and later stuff. I think the later ones only had one wire and a bad ground was a common cause of failure, but I don't think that's the case on earlier ones. I would check that it works with your ignition switch before discounting it altogether.
- Thread starter
- #9
OK, I guess I'll try giving her a drink, where should I look for the solenoid?
1911
chupacabra
On the rear, engine-side of the carb, behind the accelerator pump linkage. You can see it at the top left of this photo (of my 1980), where the yellowish wire insulation sleeve terminates.
There should be a green plug at the front of the carb where it connects to the wiring harness. Make some jumpers and temporarily supply 12V + and - to the solenoid side of the harness. If that fixes your problem, the ground to the FCS is bad (very common) or the power wire is broken (less likely). If it doesn't fix the dieseling, then either the FCS is bad or the problem is independent of the FCS. The FCS should move and click when 12V is applied, but the click is very subtle and if you have bad hearing like me you may not be able to hear it. You can however take the FCS out of the carb body and observe the action of the little plunger when 12V is applied. It is very common on these to have a bad ground at the emissions "computer" box under the dash by the fuse block though.
