long warm up

[Bill Cal.]

It's been taking a long time to warm my engine up and we live in a mild climate. Have to continually use the choke for the first 2-3 minutes to keep it going and then after 4-5 minutes it runs fine. I suspect a cracked intake manifold but can't find it. So far I have put new copper manifold gaskets on, and re-tightened a couple of times. changed carb to no avail. checked paper gasket, looks fine. Cleaned surfaces of carb and intake manifold, Run oil over to top of manifold gasket while it's running to see if oil is sucked in or engine speeds up, Engine will die if I screw air intake adjustment all the way in on carb when warmed up. Any ideas?
Thank You!

[Jim Brierley]

I believe you are on the right track, it sounds like a too-lean fuel mixture. Check the ignition timing, GAV adjustment, etc. It also could be weak spark. Also do a compression check, an intake valve could be bad.

[alexiskai]

One thing that's helpful is to troubleshoot it just on the idle. By which I mean, keep the RPMs under 500. That will keep you on the carb idle circuit, which is simpler in design. The GAV should have no effect at that speed. You say the engine dies when you adjust the idle air mixture all the way in – are you running a Marvel or a Zenith?

[Marshall V. Daut]

Fully retard the spark lever during idle and run the RPMs up via the hand throttle above normal idle speed. Keep the throttle lever there for a couple minutes. This will make the engine run "late" and help warm it up faster. You could also slip a big piece of cardboard between the radiator and the headlight bar to block air flow through the radiator that cools the engine. That will help warm the engine up quickly, too. Just keep an eye on things so that the engine doesn't start to overheat.
It is not normal for a Model A engine to take as long as you describe to warm up to operating temperature in the climate where you live. Until you can find the cause for this and fix it, the above mentioned "tricks" should reduce warm up time drastically.
Marshall

[WHN]

Carburetor!

We live in Connecticut. Even on cold days, it only takes a minute or two to run fine.

Carburetor problems are the starting point for many Model A issues. Take it apart and clean/rebuild completely.

Good luck.

[AL in NY]

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Check for a crack in the carburetor throat......Disregard, you said you changed carburetors and that didn't solve the problem. Try checking your manifold for leaks using either alcohol or kerosene.

[40 Deluxe]

There is a strange device now on the market called a "thermostat" that does wonders for faster warmup!

[1931 flamingo]

X2
Paul in CT

[wwirz]

I was working with a fellow in our club that could not get his A to run very long unless it was wide open throttle. It was also difficult to start. Turned out to be that his spark plug gap was like .012!!! Opened up to .035 and all was fine. CHeck the spark plug gap.

[Bill Cal.]

More information about the engine:
It was a rebuilt we installed in 1971. The car is a driver and I use a couple of times a week to go to town and a Sunday drive once in a while through out the year. It does not seem to have problems with the cooling system. The plug gap is fine. Think my next step is to change the manifold. Thanks for your thoughts, Bill

[dennis lumbert]

May be obvious but if it has a vacuum wiper make sure that It is not the source of an air leak . My car had a split rubber hose at the vacuum motor causing a similar symptom.

[Bill Cal.]

Thanks, but mine has a electric wiper.

[nkaminar]

You may want to try an engine block heater. There are different configurations but you will have to be creative on getting it into the block. Maybe a T on the coolant intake hose. 90 years ago people would put blankets over their engine hoods to keep the engine warm while they went to work. You could try that in conjunction with the block heater.

[David in San Antonio]

The blanket on the hood always makes me wonder how much insulation that actually provides to slow the migration of the engine’s heat when it’s shut off. Blankets help keep mammals warm because we generate heat. Car engines only generate heat when running.
In Minnesota it was common practice when very cold to go outside and start your car at least once during the work day, and right before going to sleep at night. Block heaters were common enough to not merit discussion. One time when it was about 20 below zero F (50 degrees hotter in your freezer) when I finally got my Volvo running in the morning I just left it running the entire work day. Doors unlocked because 1. They can easily freeze shut and 2. It was Chaska Minnesota so I didn’t expect any shenanigans. When I got back to the car it was nice and toasty, the gas gauge had barely moved, and there was a half inch fissure in the dashboard running from the base of the windshield down to the radio. Oh, and the plastic floor trays meant to protect the carpeting had curled up around the edges. My conclusion: metal is hardier than plastic.

[Seabees]

90 percent of carburetor problems are electrical......