The Dreaded Hot Start Thread

[55 Fargo]

Okay, so how many have problems with "vapor lock", "percolation", hot fuel issues, that caus flooding or create hard starts????

I have owned many carburated autos/trucks, in my 35 year driving career, and do not recall too many issues with hot starts, flooding,percolating or the vapor lock voodoo.

But I do have issues with both my flatheads, being finicky, and many times down right hard to start after a drive on warm to hot days, when underhood temps can get good and hot. I have tried all the suggestions, move fuel line far away as possible from the exhaust manifold, lower float, so what is the problem, is it something I am doing, or not doing?

Is it the modern alcohol impaired fuel, is my engine drunk, and confused with this new "government green peace cocktail", or what?

Does anyone want to take a run at Me, or suggest I do some searching on this, or should I be happy that the engine still starts and gets me back home.

The 47, with a 6 volt system, is a real beach to start, once heated up, but does usually catch. The 55Fargo, will restart much easier, with 12 volts, and then needs to clear, and then runs smooth again.

I do expect this sort of thing in 90 degree weather, but not on a 70 degree day.

Well thats my story, and I am sticking to it, happy motoring.....

__________________

Edited May 24, 2012 by Rockwood
common sense caution

[PatS....]

My Dad told me to put wooden clothes pins along the fuel line from the pump to the carb...solved the problem right away. Those old farts were smart-alecs sometimes

[Young Ed]

What is your hot start starting procedure?

[claybill]

Hold throttle down, no pumping, getting as much air as possible...

[TodFitch]

I've had more heat related fuel issues since California started having ethanol in the gas. But they only occur for me at temperatures above 95°F or so. So having problems at 70°F sounds like something else.

You've done the fuel line re-route and lowered the float. Have you checked to see if it is really a fuel problem? Sometimes things like a coil going bad can cause that same type of issue.... Might want to check the carb for fuel and the plugs for spark next time the problem occurs to see which it is.

[55 Fargo]

I have tried all the suggested methodss, dfor the starting procedure, but when the gas in ther lines is good and hot, it is good and hot.

I typically hold the gas pedal down, no pumping, this gets her started, sometimes I hold the pedal rightr to the floor.

A few times on super hot days, my engine would start, then it would bog, thios happened, until fuel mpump and under hood temps cooled down, and that was that.

again, find the 12 volt way easier to start, both cold or hot, just the way it is, in my case.....

[55 Fargo]

I've had more heat related fuel issues since California started having ethanol in the gas. But they only occur for me at temperatures above 95°F or so. So having problems at 70°F sounds like something else.

You've done the fuel line re-route and lowered the float. Have you checked to see if it is really a fuel problem? Sometimes things like a coil going bad can cause that same type of issue.... Might want to check the carb for fuel and the plugs for spark next time the problem occurs to see which it is.

Thanx Tod, the carbs are getting mildly flooded, they are getting hot, the 12 volt starts quickly,but is mildly flooded, the 47 with a 6 volt, starts too, but much slower.

I am not saying this could be other related, but it is a pain, and I believ it is fuel related.Could this be ethanol related, or winter fuel summer fuel, symptoms.

[meadowbrook]

I really don't believe higher ethanol levels in gasoline will increase vapor lock as people seem to be assuming. Ethanol has a lower flash point than gasoline, so if anything, it will lower the propensity of the fuel to vaporise.

Ethanol is added to increase the oxygen levels of the fuel to clean up emissions.

[JIPJOBXX]

Just like the hot start thread I have a problem with starting my old Dodge when it is cold and has not been started for over a month or so? I have resigned to the fact that I haft to take oft the aircleaner and just pour a little gas directly into the carberator and then it will start right up! I know in the beginning our cars would start right up after a prolonged period of not running but now it seems that its just the norm? Is it the gas or what? Jon:cool:

[55 Fargo]

Okay drove 10 miles into town, then shut off engine, for 5 minutes. Outside ambient temp 68, engine temp 160.

I cranked over, without touching gas, no start, then psuhed down gas pedal 1/2 way no start, pumped it 2 times while cranking, started up.

Next drove home 10 miles, stopped engine for 30 seconds, hit starter button no foot on gas pedal, fired right up. Let engine sit about 3-5 minutes, tried starter button, no foot on gas pedal, would not start, tried putting pedal 1/2 way, no start, pumped pedal slowly 2 times, fired right up, had to keep gas pedal to floor mometarily.

Well thats my story, is this carb screwed, what might be the problem?

I can see aggravation at 80-100 f, but not at temps in 60s, and underhood temp don't seem all that hot........PS going out to roto-till garden, Humming birds, goldfinches, and Orioles are all hanging out today

[claybill]

my experience....you have to floor that pedal to allow max air thru carb venturi....

my experience (last week)----when the 6v battery is low and it turns over

s l o w l y , the fuel pump diaphragm doesnt amount to much....with a stronger battery with quicker starter turnover it can pump the necessary fuel for a cold start.

I charged my battery , NOW it turns over pretty fast and booooom! STARTED RIGHT UP.

[greg g]

My owners manual states that the throttle should be open 1/3 while cranking a warm engine.

[greg g]

a couple sorces say the gasoline's boilig point is 203 and ethanol is 172. That is basically a 60 degree earlier platau. I would submit the the ethanol in gas would start expanding due to heat much earlier than it boils and evaporates. So if you have under hood tems near the carb of 160 degrees or more, I think you got a problem with modern fuel mixes where good old gasoline would be more forgiving of the same temp.

[MarkAubuchon]

Here is my two cents. Something else is wroooong. I have driven my 47 cross country two summers in a row with temps well into the 90's and the engine temp somtimes getting to 200. It would always restart. If you are still using the mechanical fuel pump make sure you have the shields in place, make sure the line from the tank is up along the frame rails and when it gets near the engine make sure its up and away from anything hot. Float level, check it again or better yet send it off to George Asche and let him rebuild it, best $100.00 you can spend. Timing, always good to check it and finally your coil. Make sure your coil is mounted correctly and is new and it is not getting hot. When you got to start it, hold the pedal to the floor and let her crank. Best of luck

[55 Fargo]

Here is my two cents. Something else is wroooong. I have driven my 47 cross country two summers in a row with temps well into the 90's and the engine temp somtimes getting to 200. It would always restart. If you are still using the mechanical fuel pump make sure you have the shields in place, make sure the line from the tank is up along the frame rails and when it gets near the engine make sure its up and away from anything hot. Float level, check it again or better yet send it off to George Asche and let him rebuild it, best $100.00 you can spend. Timing, always good to check it and finally your coil. Make sure your coil is mounted correctly and is new and it is not getting hot. When you got to start it, hold the pedal to the floor and let her crank. Best of luck

Everything you have suggested has been done or is as you have suggested.

I do thank you, for your reply, I am curious though, why would I need to send the carb to George Asche, is there something, he may be able to troubleshoot? This carb is super clean, but hey who knows maybe something is wrong.

I would not dismiss, ethanol blended fuel as an issue though, but is there any empirical evidence to support or refute this....

Edited May 25, 2012 by Rockwood

[Don Coatney]

I enjoy driving the 47, but get annoyed when I have to drive in warm weather, and this problem persists intermittently, almost makes a guy want to convert to 12 volts, for the faster spin. My battery is 6 years old, it could be getting weaker....

A good battery does wonders when starting a car in hot and cold weather. Take Norms Coupe's advice. Buy a new battery.

[Rodney Bullock]

Rockwood, what condition is your fuel pump in? That is how old is it? I used to have a hot start problem and I changed three things. The diaphamn in my fuel pump was in bad shape. I sent it to a place that used a special rubber that was not hrt by the modern gas. I also had a bad dist. meaning my bushings were worn and my points would change when the car got hot. I had the dist. rebuilt, finally I would buy those period correct coils. They were used and alot of times the fluid inside would be dry. I started buying new coils. I don't know which thing was my problem however my hard start when hot problem does not exist anymore. Like someone said earlier it might be something else. who knows......I always use the wooden close pins they Do work:) I don't know why they do.

[Jim Yergin]

Rodney,

Where did you find wooden clothes pins?

Jim Yergin

[55 Fargo]

Battery is 5 years or so old, I do have new custom made 2/0 cables, but also have a generic battery cut-off switch on the battery. Could that restrict and cause resistance, while cranking engine.

I also discovered no engine to frame ground strap. I probably could use a new battery...

[Captain Neon]

I really don't believe higher ethanol levels in gasoline will increase vapor lock as people seem to be assuming. Ethanol has a lower flash point than gasoline, so if anything, it will lower the propensity of the fuel to vaporise.

Ethanol is added to increase the oxygen levels of the fuel to clean up emissions.

Wouldn't a lower flash point mean that it is more likely to vapourise and not less likely?

[MarkAubuchon]

George Asche knows how to build carbs and set them up the right way. There is an old saying "you dont know what you dont know". What you got right now is working. I say its the carb.

[55 Fargo]

Thanx all for your replies, on this topic, and my dilemna.

I have searched and found I have been flogging this "dead horse", off and on for years.

I have rebuilt this carb, fuel pump puts out the correct volume of fuel.

I have a rebuilt distributor, newer coil, wires plugs etc.

But this sumbich, is a PITA to start after a highway drive, , it makes it difficult to want to go for a ride on a nice warm day.

Today we have Seattle weather, 50s, fine spray outside. I go for a short drive, then come home, engine just warmed up, re-starts no problem. If I went on a the highway, stopped for a few minutes, it would be a bugger to restart.

I am tired of trying to figure this out, and don't want anyone else wasting there time on it either, I should have been able to correct this years ago, but I have failed.........

[meadowbrook]

Wouldn't a lower flash point mean that it is more likely to vapourise and not less likely?

Sorry, I meant higher, and Diesel is higher yet, so it makes sense that the more ethanol, the harder it is for the fuel to vaporize and thus a lower propensity to vapor lock.

[46Ply]

My hot start solution.    Crank for 3 to 5 seconds, foot off accelerator.  Then slowly push accelerator to about one third.  Might stumble slightly but then off she goes.

 

Found this procedure here:   http://www.thecarburetorshop.com/Troubleshooting.htm

[55 Fargo]

My hot start solution.    Crank for 3 to 5 seconds, foot off accelerator.  Then slowly push accelerator to about one third.  Might stumble slightly but then off she goes.

 

Found this procedure here:   http://www.thecarburetorshop.com/Troubleshooting.htm

yup, that'll woyk......