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Runs great cold!

  • Thread starter Thread starter 66Dog&Pony
  • Start date Start date Feb 17, 2013
6

66Dog&Pony

Member
Apr 15, 2002
32
0
6
Greenville, SC
Feb 17, 2013
#1
  • Feb 17, 2013
  • #1
Yep, as strange as it sounds, its true. 70 Mustang base, 302, automatic, Motorcraft 2100D carb.
Vehicle starts, idles and runs well until it starts to warm up. Then, if sitting and idling it just dies. If moving, it stalls. In either case, it won't restart without starter fluid until it cools and won't idle when started with starter fluid. I have tried adjusting idle mixture screws, points, plugs, condenser have been replaced. Don't believe it to be a dashpot issue since it stalls when just idling. The book says this can be caused by a bad thermostat? Never heard of a thermostat causing this before. Any other suggestions would be greatly be appreciated.
 

tos

Founding Member
Apr 27, 2001
896
68
59
Cincinnati Ohio
Feb 17, 2013
#2
  • Feb 17, 2013
  • #2
Is your choke operating properly? Your book may be refering to the thermostatic spring that opens your choke as it warms up. If its talking about your cooling system thermostat then you could be experiencing vapor lock in your fuel line. In this case your coolant wont circulat and your engine will get very hot while your radiator will just be warm or barely hot. If your fuel line runs anywhere close any part of the engine it will cause a vapor lock and block the fuel flow.

when your engine stalls make sure you still have fuel squirting into the carb.
Also do you have electric choke, or manual
 
6

66Dog&Pony

Member
Apr 15, 2002
32
0
6
Greenville, SC
Feb 17, 2013
#3
  • Feb 17, 2013
  • #3
tos said:
Is your choke operating properly? Your book may be refering to the thermostatic spring that opens your choke as it warms up. If its talking about your cooling system thermostat then you could be experiencing vapor lock in your fuel line. In this case your coolant wont circulat and your engine will get very hot while your radiator will just be warm or barely hot. If your fuel line runs anywhere close any part of the engine it will cause a vapor lock and block the fuel flow.

when your engine stalls make sure you still have fuel squirting into the carb.
Also do you have electric choke, or manual
Click to expand...


Choke is mechanical, original, heat driven. Seems to be working properly. Not a vacuum leak, just replaced all vac lines. Gas is going into carb when hot or warm. Not really running long enough to heat up fuel line to cause vapor lock. I am sure there is something I'm overlooking but I just figure it out.
 

horse sence

15 Year Member
Nov 29, 1999
12,184
8,009
233
Wile Coyote's stunt double
Feb 17, 2013
#4
  • Feb 17, 2013
  • #4
float level to low or bad fuel pump, will it pump gass when the butterflys are opened after it dies?
sounds like the bowl goes dry. could also be a pluged filter inside the tank on the pick up tube.
 
J

j69302

Active Member
Jan 31, 2006
325
1
29
Feb 18, 2013
#5
  • Feb 18, 2013
  • #5
Its a long shot, but try it with your gas cap off. If your tank is not venting properly, it can cause enough vaccum to overcome the fuel pump and prevent fuel from flowing.

Does your gas tank look like its been collapsed?
 
6

66Dog&Pony

Member
Apr 15, 2002
32
0
6
Greenville, SC
Feb 18, 2013
#6
  • Feb 18, 2013
  • #6
Thanks for the tips. Gas gets to carb fine, no pump or tank venting issues. Noticed yesterday that engine stalls as choke plate opens when engine is warming up. If I hold choke plate slightly more closed than it "wants" to be based on temp the engine runs fine. I'm assuming this means choke and/or idle mix settings?
 

Smitten65

Member
Jan 7, 2011
57
4
19
FL
Feb 18, 2013
#7
  • Feb 18, 2013
  • #7
Except for when you say "it won't restart without starter fluid until it cools and won't idle when started with starter fluid. ", my thought is simply a maladjusted choke. However that shouldn't require starting fluid to overcome, just a couple of pumps on the pedal should allow it to re-start. Just for ha-ha's, the next time it stalls after warming up, check to make sure a good solid stream of gas is injected into the barrels when the throttle is opened. If not or if it is a weak stream, take the top off the carb check the float level as horse sense suggests.
 

Badscotts68

New Member
Jan 24, 2013
24
1
4
Bay Area, ca.
Feb 23, 2013
#8
  • Feb 23, 2013
  • #8
Food for thought, My 68 carbs shot, and it just dumps unregulated fuel into the motor. The car sputters, and stalls, but always starts up cold. Check your oil pan to see if this is happening with yours. It will flood the pan, dilute the oil, and cook the motor if not drained. Mine will flood the float bowl, and leak fuel from the carb/manifold gasket
The car has the suspension out, and it will be fixed before its on the road again.

Good luck
 
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