OK...

Let's try this one more time and I am going to leave it alone.

You have to have a partially opened choke plate for the engine to start. It needs air.

There is a big difference in the choke un-loader and the choke pull-off. The engine has to start before the choke pull-off feature can operate.

There is no way the OP is going to get a cold start problem corrected with people throwing all kinds of theory at him.

Again, the H4180C is an Emissions Calibrated CARB and is calibrated lean to start with. All adjustment(s) have to be within listed calibration for the carb to function correctly unless one is modifying it.

http://s7d9.scene7.com/is/content/GenuinePartsCompany/1787733pdf?$PDF$

 

We will have to disagree on the choke being completely closed during the initial start. Here's an article I found which may help a little bit. https://www.hemmings.com/magazine/mu...t/2144991.html

One thing I read in the article that I did not mention and they did, the pivot point for the choke plate is not in the middle. So as the engine starts and runs, the air pulling against the choke plate will help to open it up. But you can see in the article down in the "Diagnostics" section and under the "Hard starting" paragraph they mention the choke should be fully closed on a cold engine.

Hard starting: Check to verify that the choke plate is closing fully when the gas pedal is tapped and that the plate maintains spring tension when closed. If the choke does not close, then either the linkage is gummed up, the air horn is warped, or the spring tension is too loose or the choke spring has experienced a failure such as an internal break.

Below that they mention the choke pull-off and how the engine will flood and blow black smoke if it doesn't open the choke door enough after initial start up.

Loads up/blows black smoke after running a few minutes: The choke plate is not opening enough after the engine starts. This can be caused by a misadjusted pull-off, a worn diaphragm in the pull-off that has either torn or has swelled and is not moving enough, or a fast-idle speed that is set too low. It is common to find all of these things wrong with an older carburetor.

The carb rebuild instructions have a spec for the choke pull-off adjustment. You are usually measuring how much the choke door cracks open. Not enough and the engine runs rich. Too much and the engine will stall after starting.

 

Disagreement is not the issue. Facts are-

The HEMMINGS ARTICLE is a generalization of all choke types and not specific to this type.

An engine cannot start/run with a fully closed choke valve (unless there is leakage somewhere). That is what the OP is describing, a very rough start.

I've said my peace and wish to leave it alone.

 

Thanks for the .pdf link, that is the document I followed initially, did not even know it was the shop manual.

I cannot see the choke plate position (bit open or totally closed) from inside the cab, no one to help on this recently. The start is pretty consistent: 3 pumps on the gas and it starts right up, in colder temps it idles slower and rough sometimes stalls, warmer temps a bit smoother and doesn't threaten to stall. Still seems like a flooding condition today after driving 30mins and then trying to start it 40mins later, although I was able to pump the gas 4-5 times and get it to start. I still plan to try to turn the fast idle adjust screw, hopefully tomorrow.

One other thing to report is when the truck is all warmed up it runs good and idles quiet and steady and when I put it into park the idle goes up enough that I think it could be a little high but as you maybe can tell, I don't know much about this system... is it supposed raise the engine rpms on a fully warmed up engine when shifted into park ?

 

Let's start over.

A properly operating choke is as follows. You get into vehicle and turn IGN SW to ON. You depress the ACCEL PEDAL ONCE to the floor and release. Do not pump or hold at part throttle. Put that right foot on the dash if you have poor motor skills ...

The engine should start and go to FAST IDLE. If not, either the CHOKE is out of adjustment or you have other problem(s).

A pencil width is way to much. The carb will run lean and most likely will not stay running without as re-start.

Print out those instructions, get an iced tea or coffee and cipher. DO NOT REACH FOR A COLD ONE. This may interfere with understanding the text and illustrations. Again, the H4180C is an emissions compliant carb calibrated extremely lean and the settings



must be exact for the choke to operate correctly. You can get away with close enough with an older 4150/4160 but this one has to be exact (along with state of tune).

As for higher RPM when put into PARK, you have just removed the AT load off the engine. It will idle faster. There is an adjustment(s) for this.

 

 

thanks again for detailed directions to try. I tried again for 30mins to get a tool on that screw, not even close!

I want to pull the carb (unless there that creates more issues that I am not aware of?)

I will turn that fast idle screw: which way and how much? I am guessing the idle is somewhere around 500rpm right now. I am hoping I spot a way I CAN get a wrench on it after it's back on WHILE I have it off for more adjustments, I'm sure I won't get it perfect the first time.

I will make note of the stack under the carb; gaskets/spacers etc.

Anything else to check there while I have it off?

I didn't have any special lubes or sealers when I installed the carb, nothing like that is needed eh?

thanks again, and again...

 

 

If you open/close the throttle shaft, does getting to the adj screw get any easier?

There are special tools made for situations such as this but are $$$

 

They don't have to be *that* expensive....

 

Price:$22.39 & FREE Shipping
You have to weigh the price on whether to buy the tool or re-stock the fridge with beer ...

I need to get up off my butt and find my carb to hawk it out.

 

Mmmm, beeer... the fridge is closer to the couch than the carport. Note to self: pick up a fridge & couch for the carport!

AND thanks to all posters, I WILL pull that carb today.

 

Pulled it twice of course and now it won't start! hehe on the first attempt I turned it about a half turn and put it back on. It started right up (maybe quicker than normal) so I though I was going the right direction but the idle wasn't noticeably better so I shut it down and pulled it again, this time adjusting just under a half turn and now it won't catch. Gonna take a look at it in the morning with good light and if it looks like I had all the connections back where they are supposed to be I will maybe pull it again and start over going the other direction...

the pics helped but with the carb full of gas I didn't turn it over to get a good enough look at the throttle plate position, holding it over my head to peek at it obviously didn't work well! is it ok to just turn it over?

 

Well, yes and no. If it has fuel it will most likely have some type of sediment in the bowls so that will be disturbed. Try to drain the bowls gently.

I am getting up off my fat lazy butt as I post to find mine. I shall return (how many years did it take MacArthur?)

EDIT -

OK, I am back.

On my version (D9TE BKA) (early version) the fast idle cap screw is fairly accessible. If you open the throttle by hand, it drops to where you should be able to get an open end on it. Of course, yours may be somewhat different.