In a Quadrajet with an electric choke, are the butterflies supposed to be open or closed at outside temperature of 75 degrees F with the engine not running?

Jim

Closed, if the engine is cold too, electricity heats then to open!

Agreed

Wifey went out yesterday to a cold engine, turned the key and it started right up, ran for 10 seconds, and stopped cold. Wouldn't restart. Checked for spark at plug, has spark. Now changing small filter in q-jet to see if that was the problem

J

Jim, Don't you just love these old 454 engines!!!! Hey check for the other way around too, might just have a stuck float and it flooded, rather than starved for gas!!

Good Luck!!!

BTW I have a couple of rebuild kits for your carb, would send you one if you need it, like to see them get used.

We replaced the fuel filter in the q-jet, put a different coil on it, blew out the fuel line from the fuel pump located on the block, put everything back together and it started. For the next 4 weeks, we didn't do anything except take it our of the garage a few times to drain the water tanks. Yesterday, Tere drove it about 20 miles to get the windshield fixed and on the way back, as soon as she took her foot off the gas, it died. She was only 2 miles from the house and that happened 2 more times, including one time when there were 3 loud backfires. She was able to get it home by keeping pressure on the gas peddle but as soon as she got it in the driveway to back it in the garage, it quit again and this time it wouldn't restart however the starter motor was working. She had left the heat shield off the starter motor but since the starter motor still was working, I don't think the starter selenoid is the problem. A couple of hours later, she went out and it started right up. It was about 80 degrees yesterday. The PO, Jerry Davis, had driven the Barth over 300 miles including up over the Smokey Mountains to bring it to us and he had no problems. I drove it from the campground Jerry was staying at to our house which is about 40 miles, with no problems. So from 9-16 to 10-22, we only started it a couple of times but when Tere used it on 10-22 it died after 20 miles or so. Vapor lock? Jerry didn't have any trouble. Grounds? As long as she kept the RPMs up it stayed running until it finally died for good in the driveway. I do remember once with a Ford Class C, the problem ended up being a clogged catalytic converter. But, as I recall, it wouldn't start at all even after letting things cool down.

like this?

https://www.barthmobile.com/eve...1087061/m/9543924087

https://www.gm-trucks.com/foru...stalling-at-low-rpm/

https://www.hemmings.com/stori...-of-choke-adjustment

Jim, my bet is when you blew out the fuel lines, you loosened some debris, change the fuel filter in the Q-Jet. Perhaps the fuel pump was damaged also, do you have a fuel pressure gauge and an auxiliary electric fuel pump in line?

Prior to putting an extra fuel filter inline, an electric fuel pump and gauge, ole Nose starved for fuel backfired and begged for Gasoline the Q-jet filter clogged all the time sometimes with very few miles.

After Nose sat for a bit the filter would allow flow for a brief time when it was clogged. Nose usually backfired and missed when I floored it though. Good luck!!!

With the problem you are having I would invest in a fuel pressure gauge. You will most likely have to tee it in to the metal line from the fuel pump. This will let you know if its a fuel delivery or a problem in the Qjet. (stuck float, dirt plugging jets). I think your coach has a high pressure pump in tank to fuel regulator to filter to engine mounted fuel pump. an oil pressure switch cuts power to tank pump.

A few thoughts .

When you replaced the coil , did ya'll put in a new ignition module ? Do the distributor weights move freely ?

Does the choke fully open when the engine warms up ?

Is it possible that you picked up contaminated fuel ?

Check the distributor wiring for shorts or bad ground . I've had more ignition problems cause backfiring than carburetor problems .

I had a truck once that had trash in the fuel tank . The screen wasn't on the pick up tube and there was a blob of silicon that would stop up the tube randomly . Sit for a bit it would start and run fine . Might go a month or an hour before it did it again . Sure was happy when I found the problem.

I would first check the simple things. Did the ignition timing change as a consequence of the coil job? Is the distributor clamp still tight? Are all the vacuum lines solid and connected properly?