Samhammett Posted November 13, 2019 Share Posted November 13, 2019 Went out to fire up the truck this morning, first time I have tried to start on a cold morning. It was 20f this morning and it wouldn’t start at all. Tried key off/on/off/on to see if that would work, tried key on and letting it sit for 10 seconds or so and tried giving it gas while cranking and got no where. Went out after lunch and got the same result, sprayed some ether in the carb and it started straight away. I’ve never had any trouble starting before other than an odd backfire once or twice. It’s a 86 4.9l with the factory carb system installed. Any ideas where to begin? This is all new to me Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 13, 2019 Share Posted November 13, 2019 I'm guessing the choke isn't coming on fully. Did you press the throttle down before trying to start it? That is a MUST as it allows the choke to set, and without the choke it won't start. If you did push the pedal down then you need to see if the choke is coming on. Pull the air cleaner and see where the choke is sitting and then open the throttle a bit and the choke should close fully, or almost fully. Link to comment Share on other sites More sharing options...
1986F150Six Posted November 14, 2019 Share Posted November 14, 2019 Went out to fire up the truck this morning, first time I have tried to start on a cold morning. It was 20f this morning and it wouldn’t start at all. Tried key off/on/off/on to see if that would work, tried key on and letting it sit for 10 seconds or so and tried giving it gas while cranking and got no where. Went out after lunch and got the same result, sprayed some ether in the carb and it started straight away. I’ve never had any trouble starting before other than an odd backfire once or twice. It’s a 86 4.9l with the factory carb system installed. Any ideas where to begin? This is all new to me Try these links: https://www.ford-trucks.com/forums/1141009-4-9-having-problems-starting-cold.html https://www.ford-trucks.com/forums/1110073-choke-adjustment-101-a.html Link to comment Share on other sites More sharing options...
Samhammett Posted November 14, 2019 Author Share Posted November 14, 2019 I'm guessing the choke isn't coming on fully. Did you press the throttle down before trying to start it? That is a MUST as it allows the choke to set, and without the choke it won't start. If you did push the pedal down then you need to see if the choke is coming on. Pull the air cleaner and see where the choke is sitting and then open the throttle a bit and the choke should close fully, or almost fully. I hadn’t tried pressing the pedal to the floor first and then cranking. Tried that this morning and it caught right away and then sputtered and died. Pressed the pedal to the floor, released and then cranked again, caught sputtered and died. All in all it did that maybe 3~4 times and then it stayed running. I’m assuming the carb must still need some adjustment, but should I be doing something else for a cold weather start besides just pressing the gas fully, releasing fully and then cranking? Thank you for your help! Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 14, 2019 Share Posted November 14, 2019 I hadn’t tried pressing the pedal to the floor first and then cranking. Tried that this morning and it caught right away and then sputtered and died. Pressed the pedal to the floor, released and then cranked again, caught sputtered and died. All in all it did that maybe 3~4 times and then it stayed running. I’m assuming the carb must still need some adjustment, but should I be doing something else for a cold weather start besides just pressing the gas fully, releasing fully and then cranking? Thank you for your help! Welcome to the world of driving a carbureted vehicle. Pressing the accelerator at least part way down before starting a cold vehicle is a requirement. That does two things: first, it allows the choke to set, and the choke is needed to enrichen the air fuel mix. Second, it squirts a jet of fuel into the intake that also helps to enrichen the mix. But if your engine doesn't stay running the choke probably isn't set quite right. There should be three screws that can be loosened, not removed, holding the black choke housing to the carb. Once those are loose you can rotate the housing slightly, maybe one mark, toward the rich side. Then snug the screws down again. However, you may be able to keep the engine running when it initially starts by giving the accelerator a few extra stabs, thereby squirting more fuel in. Go gently as you might get too much and flood the engine. Link to comment Share on other sites More sharing options...
LARIAT 85 Posted November 14, 2019 Share Posted November 14, 2019 I hadn’t tried pressing the pedal to the floor first and then cranking. Tried that this morning and it caught right away and then sputtered and died. Pressed the pedal to the floor, released and then cranked again, caught sputtered and died. All in all it did that maybe 3~4 times and then it stayed running. I’m assuming the carb must still need some adjustment, but should I be doing something else for a cold weather start besides just pressing the gas fully, releasing fully and then cranking? How long had it been since it was last started? On carbureted vehicles, that makes a difference. If your truck was running yesterday and you wanted to drive it this morning, it should only take one pump and the engine should start right up and continue running. (When I say "pump", that means push the gas pedal to the floor once and release it fully. Then, turn the key.) But if has been sitting for a few days, the carburetor loses pressure and the intake begins to dry out. If your truck has been sitting for 3 days, pump the gas 3 times before starting the engine. If it has been 5 days, pump the gas 5 times before starting. My own truck starts right up by following the above starting procedure. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 15, 2019 Share Posted November 15, 2019 Welcome to the world of driving a carbureted vehicle. Pressing the accelerator at least part way down before starting a cold vehicle is a requirement. That does two things: first, it allows the choke to set, and the choke is needed to enrichen the air fuel mix. Second, it squirts a jet of fuel into the intake that also helps to enrichen the mix. But if your engine doesn't stay running the choke probably isn't set quite right. There should be three screws that can be loosened, not removed, holding the black choke housing to the carb. Once those are loose you can rotate the housing slightly, maybe one mark, toward the rich side. Then snug the screws down again. However, you may be able to keep the engine running when it initially starts by giving the accelerator a few extra stabs, thereby squirting more fuel in. Go gently as you might get too much and flood the engine. Gary, be mindful that all stock carburetors came meeting federal tamper-proof regulations. If that's the case, there will be only three conical nubs from the breakaway screws used for assembly. One can use a Dremel cutoff disc to make a slot for a straight screwdriver, grind a couple of flats and use pliers or an ignition wrench, or -if the carb is dry and on the bench- drop a #10/ 3/16" nut over the nub and weld it on. At any rate replace the screws with Phillips, Allen or Torx one at a time so as not to disturb the setting. And note the alignment of the mark on the cap with the indicator mark on the choke body so you can get back to this baseline if needed. The marks on the choke will be similar th the vernier on the barrel of a micrometer, or the timing marks on the damper. The one longer, bolder line showing how many tics clockwise or anti clockwise the choke is set. Long winded explanation, but I'm just trying to cover the bases in simple terms. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 15, 2019 Share Posted November 15, 2019 Gary, be mindful that all stock carburetors came meeting federal tamper-proof regulations. If that's the case, there will be only three conical nubs from the breakaway screws used for assembly. One can use a Dremel cutoff disc to make a slot for a straight screwdriver, grind a couple of flats and use pliers or an ignition wrench, or -if the carb is dry and on the bench- drop a #10/ 3/16" nut over the nub and weld it on. At any rate replace the screws with Phillips, Allen or Torx one at a time so as not to disturb the setting. And note the alignment of the mark on the cap with the indicator mark on the choke body so you can get back to this baseline if needed. The marks on the choke will be similar th the vernier on the barrel of a micrometer, or the timing marks on the damper. The one longer, bolder line showing how many tics clockwise or anti clockwise the choke is set. Long winded explanation, but I'm just trying to cover the bases in simple terms. I forgot that, Jim. Thanks. And good explanation. Link to comment Share on other sites More sharing options...
Recommended Posts