Gary Lewis Posted May 10, 2018 Share Posted May 10, 2018 Well - back to report that I got the fuel filter swapped out. Plugs and wires not done yet but while I was in the engine bay I took a moment to check all my spark plug wires and found 2 that were loose (pulled off extremely easily). I reseated those and felt them 'click' on - so now all is secure there. I did have a bit of time getting the fitting from the fuel line not to leak once snugged into the fuel filter. Turned out to be an alignment issue so the flared end of the fuel line was not seating properly where it meets the fuel filter. After I fixed that alignment and tightened back down - no more leak! I haven't driven it around the neighborhood yet to see if it shakes loose or backs off and starts leaking but I will in the next day or two. Once I had the fuel leak solved, I left the engine idling while observing/listening. I accidentally pushed down on the linkage between the choke housing/pulldown housing/pull down lever. Engine died immediately. Nothing seemed to have come off - everything was still connected. Restarting the engine proved to be a pain - it's like the choke didn't set the last time and it would not hold idle. I had to feather the throttle each time to get the truck to start and it would only hold idle for a couple minutes before just stopping, no die down in the engine like it was getting starved, just all of a sudden - stop. I was running out of time for the day so I had to button it back together and haven't been able to go back out to see if it just needed some time rest or what. Thoughts on where to trouble shoot next? I also shot some video of the truck idling if anyone wants to take a gander - I'll figure out where to host it and share it out if interested. Good progress on the plug wires and fuel line. As for the engine dying, I'm going to guess it is quite lean. When you pushed down on the linkage you probably opened the choke and it died. And since the choke was now partially warm it didn't come on enough to get the engine to start easily. Feathering the throttle would cause the accelerator pump to squirt fuel into the mix, thereby making it richer. All of this hinges a bit on the idle air/fuel mix. If you have it adjusted a bit lean then it really needs the choke to idle until the engine warms up. And with the engine partially warm the choke won't come back on fully. So, I'd get the engine warmed up and adjust the idle air/fuel mix to get the best idle, either RPM or vacuum, and then see how it does. If it is still balky when cold you may need to bring the choke on a bit further. Link to comment Share on other sites More sharing options...
JMUBullnose Posted May 10, 2018 Author Share Posted May 10, 2018 Good progress on the plug wires and fuel line. As for the engine dying, I'm going to guess it is quite lean. When you pushed down on the linkage you probably opened the choke and it died. And since the choke was now partially warm it didn't come on enough to get the engine to start easily. Feathering the throttle would cause the accelerator pump to squirt fuel into the mix, thereby making it richer. All of this hinges a bit on the idle air/fuel mix. If you have it adjusted a bit lean then it really needs the choke to idle until the engine warms up. And with the engine partially warm the choke won't come back on fully. So, I'd get the engine warmed up and adjust the idle air/fuel mix to get the best idle, either RPM or vacuum, and then see how it does. If it is still balky when cold you may need to bring the choke on a bit further. Alright - back to the reading board for me!! Thanks Gary. Question I've been meaning to ask: When the choke is first set and the choke plate is closed - should it be firm up against the air horn or is there a slight gap? My truck usually has the latter...maybe a 1/16" gap in between the choke plate and the air horn. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 10, 2018 Share Posted May 10, 2018 Alright - back to the reading board for me!! Thanks Gary. Question I've been meaning to ask: When the choke is first set and the choke plate is closed - should it be firm up against the air horn or is there a slight gap? My truck usually has the latter...maybe a 1/16" gap in between the choke plate and the air horn. Most chokes aren't supposed to be hard against the carb body. So 1/16" is probably fine. But Bill may have a dimension - I don't. Link to comment Share on other sites More sharing options...
1986F150Six Posted May 10, 2018 Share Posted May 10, 2018 Most chokes aren't supposed to be hard against the carb body. So 1/16" is probably fine. But Bill may have a dimension - I don't. Some chokes have a pull-off solenoid, so the choke plate is fully closed at rest. As soon as the engine turns over and creates a little vacuum, the plate is opened slightly. Link to comment Share on other sites More sharing options...
JMUBullnose Posted May 21, 2018 Author Share Posted May 21, 2018 Good progress on the plug wires and fuel line. As for the engine dying, I'm going to guess it is quite lean. When you pushed down on the linkage you probably opened the choke and it died. And since the choke was now partially warm it didn't come on enough to get the engine to start easily. Feathering the throttle would cause the accelerator pump to squirt fuel into the mix, thereby making it richer. All of this hinges a bit on the idle air/fuel mix. If you have it adjusted a bit lean then it really needs the choke to idle until the engine warms up. And with the engine partially warm the choke won't come back on fully. So, I'd get the engine warmed up and adjust the idle air/fuel mix to get the best idle, either RPM or vacuum, and then see how it does. If it is still balky when cold you may need to bring the choke on a bit further. Alright - so I've been attempting to get the choke set back to where it was when I could get the truck to start and idle more reliable (ie - before the fuel filter swap). I've "played" with the choke housing cap a little to try and get it back to where it was before I started messing with the fuel filter and accidentally bumped it forward. The choke cap is an OEM but non motorcraft one installed by my local shop a couple years ago. It feels like the choke just isn't setting when I go to start the truck cold. Engine won't kick over for a good 20 seconds unless I bump the accelerator slightly and even then it won't hold an idle just chokes off and dies ~20-30 seconds after start. Even after sitting in the cab and lightly feathering the throttle to keep the RPMs up for a minute or two, the truck died as soon as I put it in gear. I was eventually able to get going and it restarted fairly easily afterwards since the engine was warm. Not sure what to adjust next - just want to get this back to starting/running reliably! I'm definitely a bit out of my league but want to learn/get it right so I don't have to rely on a shop. Thanks as always! Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 22, 2018 Share Posted May 22, 2018 Alright - so I've been attempting to get the choke set back to where it was when I could get the truck to start and idle more reliable (ie - before the fuel filter swap). I've "played" with the choke housing cap a little to try and get it back to where it was before I started messing with the fuel filter and accidentally bumped it forward. The choke cap is an OEM but non motorcraft one installed by my local shop a couple years ago. It feels like the choke just isn't setting when I go to start the truck cold. Engine won't kick over for a good 20 seconds unless I bump the accelerator slightly and even then it won't hold an idle just chokes off and dies ~20-30 seconds after start. Even after sitting in the cab and lightly feathering the throttle to keep the RPMs up for a minute or two, the truck died as soon as I put it in gear. I was eventually able to get going and it restarted fairly easily afterwards since the engine was warm. Not sure what to adjust next - just want to get this back to starting/running reliably! I'm definitely a bit out of my league but want to learn/get it right so I don't have to rely on a shop. Thanks as always! Sorry for the late reply. When you try to start the truck are you depressing the pedal once before you turn the key? That’s a requirement with a carb or the choke can’t set properly. Once started then the fast idle linkage comes into play to keep it running. There’s an adjustment for that on the back of the carb, passenger’s side. Link to comment Share on other sites More sharing options...
JMUBullnose Posted May 22, 2018 Author Share Posted May 22, 2018 Sorry for the late reply. When you try to start the truck are you depressing the pedal once before you turn the key? That’s a requirement with a carb or the choke can’t set properly. Once started then the fast idle linkage comes into play to keep it running. There’s an adjustment for that on the back of the carb, passenger’s side. Gary - no worries on the timing - I appreciate all the help I can get! I did press the accelerator once prior to turning the ignition - still took 2 attempts at cranking to start after that. "What GIS hath wrought, let no man, except management, tear asunder" - A. Wise Analyst On Tue, May 22, 2018 at 10:06 AM, Gary Lewis [via Bullnose Enthusiasts] <redacted_email_address> wrote: Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 22, 2018 Share Posted May 22, 2018 Then check for the accelerator pump working. Pull the air cleaner, look down the throat of the carb, and work the throttle. You should see two streams of gas shoot in. If not, the engine isn’t going to want to run when cold. Link to comment Share on other sites More sharing options...
JMUBullnose Posted June 7, 2018 Author Share Posted June 7, 2018 Then check for the accelerator pump working. Pull the air cleaner, look down the throat of the carb, and work the throttle. You should see two streams of gas shoot in. If not, the engine isn’t going to want to run when cold. So - good news, found a photo I had taken about 2 months ago - so I was able to put the choke back to where it was, albeit a bit rich. Next up is adjusting the idle - it's a bit low. Just glad I was able to get the truck to start rather easily and not have it conk out on me during idle. The cold start idle is a high as well though. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 7, 2018 Share Posted June 7, 2018 So - good news, found a photo I had taken about 2 months ago - so I was able to put the choke back to where it was, albeit a bit rich. Next up is adjusting the idle - it's a bit low. Just glad I was able to get the truck to start rather easily and not have it conk out on me during idle. The cold start idle is a high as well though. Glad you found the pic. Sometimes that's all you need - a reminder of what went where. Good luck! Link to comment Share on other sites More sharing options...
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