Hard starting

JimD

Waiting for Godot...
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I have an issue with my 124 Sedan. It has a 1438 OHV with a Weber DHSA carb and automatic transmission. Hot or cold I have a hard time starting this car. It cranks forever before it finally gets fuel, at least I think that is the issue. If I shoot starting fluid in the carb it will fire, but die after the fluid is gone.

When cold, I pull the choke and keep cranking till it fires. Once it starts it keeps running and runs well once it warms up. If I take it to the parts store and go in for a few minutes, it starts right up when I come back with no choke needed. If I drive to lunch and let it sit for 30 minutes or so I have to go through the cranking again. Choke or no choke doesn't seem to matter at this point. It feels like it takes longer to start in this situation than when it is 100% cold. That is how it "feels" in the moment, not a scientific observation.

I added a check valve to the fuel line a couple days ago to see if it would help. I put it in the line in the engine bay between the hard line from the tank and the fuel pump. It didn't help at all as far as I can tell. What else should I look at?
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Other info just FYI: When I first got the car it had a bad fuel pump. I replaced the pump, then the car ran badly and wouldn't idle. I got a rebuild kit and have taken the carb apart, cleaned all the passages, sealed the leaky return tube, cleaned out the jets and replaced gaskets and a diaphragm or two. This got the car running pretty well and I can even set an idle now. As I said earlier, it runs pretty darn good once it is started and fully warms up.
 
just shooting from the hip it sound like a problem that I had on an old ford 360. my bowl in the carb had a leak that would flood the motor right after shut down, and after cooling off the bowl would be empty so a lot of cranking to re-fill the bowl before it could re-start.

You could put in an electric pump to re-fill your bowl before you crank to test the empty bowl thought.
 
I will check that Rod

That sounds like a possibility. There is no gas leaking where I can see/smell it, but that doesn't rules out the float bowl dribbling out somehow.

The float bowl didn't show any obvious signs of damage when I was cleaning it last fall, but I will get back in there and take a closer look with a leak in mind.
 
my ford was dribbling down the intake flooding the motor so normal warm start procedure was the it's flooded procedure.

should be an easy test.
 
So I guess I have gas in the oil too?

Hi Rod,

I think I am smelling gas on the dip stick. I guess if the fuel is dribbling into the engine it has to end up somewhere. Unfortunately I hurt my back again, third time in two months, so I can't really work on the cars right now.

Back was feeling better Monday, so I went out to put a new dog bone in the 85X. Seemed like it should have been an easy enough job to not cause another back problem. Nope. I had to do some engine tugging to get things aligned and I guess I went at it harder than I thought. I think there repeated injuries really have as much to do with the bending over into the engine bay as it is the effort expended.

I am obviously not giving my back enough rest after I hurt it, so I better head for the sofa and ask the wife to fetch me a beer. :)
 
Two issues (likely)

Hard start after sitting a prolonged time is usually fuel siphon / drain back to the tank. Gravity will suck all the fuel right out of the line and the carb bowl, and with the mechanical pump you have to crank long enough to pull fuel all the way up to the front and fill the bowl again before it fires. Fiat provided one-way fuel check valves to help with this.

The hard start 20 minutes after shutting off hot is just what others suggested, the heat from the exhaust manifold is boiling the fuel
out of the bowl, it gets pushed up out of the jets and falls right into the cylinders flooding the car.

In this scenario, theres not a lot of fixes I've found, but if you get in the habit of slowly opening the throttle with your foot at the exact moment you crank for the first time, by the time you get the throttle all the way to the floor it will usually fire up with no fuss. And as others said you have to keep an eye on your oil, as it will contaminate the oil over a few thousand miles or lots of stop-start daily driving events.

-M

-M
 
Yes, it sounds similar

Yes Rod, it sounds and smells like a similar issue. ;)
 
Thanks Matt

I put in a check valve thinking that was the problem, but it didn't help at all. I am not sure if the carb is boiling out or if its leaking somewhere internally. At FFO it had a noticeable drip going down onto the exhaust :devil:, but that was prior to the rebuild. I can't see any drips now, and there is no gas smell in the garage like there had been prior to the rebuild.

For now I will change the oil again and see if I can figure out if the carb is dripping. Maybe I will put it on the shop bench with a full fuel bowl and see what happens while its cold.
 
Maybe its time for a new carb?

Maybe its time for a new carb? If a cracked/leaky DHSA is the problem, this may be a good solution. However, if the real issue is that the car is boiling the fuel out of the carb, I don't think a new carb will make a difference. The other option seems to be living with the DHSA and changing the oil frequently.

I think I will start by changing the oil and seeing how long it takes to get contaminated with the current DHSA carb set up. That would at least give me a baseline on how bad the problem is.

Rambling thoughts an using a DFEV: In my previous thread on replacing the carb, the Weber DFEV came up as a bolt on replacement. I found a DFEV kit for the 124 on Ebay and I can see that it is very similar in set up to the DHSA on the car now. I think the DFEV has a mechanical secondary vs the vacuum secondary on the DHSA. I don't really see any vacuum ports of the DFEV, I kinda like that.
 
Gas leaking into the intake and cylinders as others are saying sounds familiar to me. Had same problem on my 350. The float was soaking up gasoline and would not completely close the check valve and would flood the engine. Once I got it started it ran ok but same thing all over each time I restarted it.
 
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