Thanks. It seemed to run fine without it today but I know itll need to be fixed. I did clean all the soot out of the choke when the carb was rebuilt. Its just a coil of flat wire inside. I’ll inspect it more tomorrow.
Fascinating. Here’s all I have on the Quadrajet and there’s no mention of exhaust gas reaching the carb:
http://www.whateveristrue.com/chevy/Rochester-Quadrajet-4MV-4MC.pdf
I’d appreciate your source for this oddity to add to my data base. Thanks.
Just looked at my shop manual. Although its not illustrated, they refer to the pipe off the choke as the heater pipe, and it is in fact supposed to be connected to the manifold. It doesnt say intake manifold or exhaust manifold, but the way the metal line is routed, Im assuming itll be the exhaust. I’ll take a look in the daylight tomorrow.
cool, you ll be cruisin’ in style soon
like you said, it ll run without out it, or at least my truck did after I broke it
I have manuals showing detailed breakdowns of the QJ and they also make no mention of this.
What do I base my comments on? Learning about it the hard way many years ago with repeat choke issues on a QJ and having to physically remove the soot from the pinhole with a jeweler’s bit, aerosol carb cleaner, and compressed air.
Pinhole opened, choke fine afterwards.
A year or so later, and wanting to modernize a bit, I plugged the entire thing off one weekend and added an electric choke pirated from an old Subaru Hitachi carburetor to the QJ.
That line goes to a “choke oven” or “choke stove”…Sometimes located under the carb in the center of the intake manifold where an exhaust cross-over kept it hot…On some cars, the line ran down to a box on the exhaust manifold where heat could be collected. Neither of these systems ever worked very well…The heat was just too slow coming and the choke stayed on too long…The 'heat risers" were replaced with an electric heating element that warmed and opened the choke quickly…This worked in conjunction with a vacuum choke pull-off which opened the choke a little as soon as the engine started, preventing flooding. Within a few minutes, the choke heater would have the choke fully opened.
I’ll have to send some pictures. There is a line that runs under the intake manifold and screws into the base of the carb, on the front between the two idle adjust screws.
Then the line Im talking about goes from the black circular thing up top which Im sure is the choke, then runs down along the edge of the valve cover and behind the engine to nothing now.
Ok, theres a small hole in the back passenger exhaust manifold where the heater pipe just popped back in. The glass bowl I tightened with some pliers and stopped the gas leak. And, the windshield wipers work now too! We did however have some heavy rain lastnight and now the intake manifold has surface rust and there was some water where it mates to the head. Strange. I wicked it up with some paper towels and watched it idle for a while, drove it, checked it, and no leaks. We’ll see. Shes still running a little rough however. Not getting a good clean burn. Its got nothing but fresh gas in it. I’ll upload a video here, or on youtube in a sec for those interested.
nice.
Are any of the plugs turning brown/black?
Wonderful! Wide whites and spats! It looks like the paint is a bit tired. If you repaint it, going with the same color will retain the dignity of a Series 61, and will be a lot easier to do since not everything needs to be painted. How is the interior?
This is slightly off the subject, but I played for a big picnic at an assisted care facility today. Not only did our band play, but our local old car club displayed the vehicles of the members. One of the vehicles was a 1950 Cadillac that was fitted with an ambulance body. This vehicle has been owned by the same funeral home since it was new. The member of the car club takes the Cadillac ambulance to shows, but the funeral home maintains and stores the vehicle. It is kept in pristine condition, but I remember when it was on active duty. I was told that this vehicle tips the scales at well over 5000 pounds. The Cadillac was the vehicle of choice back then for ambulances and hearses.
Hardly ever saw anything but Cadillacs as hearses. More recently there were Lincolns because the Town Car was made long after any GM body-on-frame luxury cars. Now I mostly see crossovers as hearses. And those monstrous stretched Escalades as prom boats, complete with rear Jacuzzi. I wonder what these are used for the rest of the year. There can’t be much demand for 20 passenger glitzmobiles in August or February. Maybe they ship them to other countries?
@Triedaq
5000 pounds is not that outrageous for an old body on frame car
Are you sure it wasn’t 10000 or 15000 pounds?
@dagosa-- I am just reporting what the man displaying the ambulance told me.
Very cool. Would love to see some pics. When this caddy died in the street on me, myself and another guy couldnt even budge it. Luckily I got it to run and limp back home. That was prior to rebuilding anything.
I have yet to pull the plugs. Im scared to unscrew everything on this car after breaking the carburetor studs. But I know I should tune up all the electrical stuff next. The throttle response is good now but it runs jagged when on the gas steady.
" But I know I should tune up all the electrical stuff next."
Bingo. And get used to pulling the plugs; they’re your view into the heart of the beast.
Yeah, luckily theyre all very easy to access. Just nervous. Imagine stripping a thread or something of that nature. I’ll probably soak them in PB blaster the night before I plan on pulling them.