500, 472, 425, 368 Discussion, Quadrajet Coil Choke in Cadillac Engine Technical Discussion; So, I've been working on the '70 Eldorado that I picked up in September. And I've finally gotten around to ...
So, I've been working on the '70 Eldorado that I picked up in September. And I've finally gotten around to the fuel system.
While looking into the horrible cold starting, I checked to see what condition the choke coil was in. Turns out - it ain't there. The coil, the linkage...everything is missing.
The Quadrajet on my '70 500 had a thermal type coil choke that sat in a heat well on the intake manifold (not the electric type that was mounted on the carb). So I went to my local parts store who promptly told me that it was a dealer item.
Am I crazy? Or should this be a really common item? At any rate, I need a choke coil kit for my '70 Eldo. Anyone have a source that they'd recommend?
Yep, that's kind of what I figured. Just needed someone to make me accept it. lol.
I probably will do a manual choke as a short-term fix. The carb could use a refresh (to say the least) and I'll probably end up replacing it with something a bit newer and less temperamental. But that's expensive and the weather is cold. So I'll probably just make due with a manual choke until Spring time.
Automobile(s): 1974 Fleetwood 6-Door Limo, 1970 Coupe Deville
Re: Quadrajet Coil Choke
I went through this little exercise with my '74 Fleetwood. I was lucky enough to find a friend on the forums with one for sale. I had to take a chance on not seeing it, and got lucky! There seems like there were a few different styles of choke, and of heat well also.
The one you mentioned looks a little different, and I have a parts book that says all 70-71 Caddies had a:
Coil and Cover, Carburetor Choke Thermostat #7038254
Let us know how it works!
Here's a pic of my "old" choke from the 74. It was still in pretty good shape, but my particular year also had a vacuum diaphragm (the Choke Reindexing Diaphragm) that was part of the choke assembly, and it was shot. So you won't see that added part in this pic.
Thanks for the info and photo. Yeah, that looks completely different from the one I ordered. However, it also looks like it would fit the heat well a whole lot tighter than what I ordered.
The heat well on my 500 looks a lot like the place where the thermostat goes in the cooling system. Two bolts, similar size and shape. Like the thermostat gasket would sit pretty neatly on it.
I figure that there is a good chance that the coil I ordered won't be quite right. Worst case scenario, I'll temporarily put a manual choke cable on it. The dash was pre-cobbled by the last owner. So I don't feel too horrible putting yet another hole in it. The entire interior needs to be re-done at some point in the distant future anyway.
The carb could use a refresh (to say the least) and I'll probably end up replacing it with something a bit newer and less temperamental.
You should be aware that the Q-jet IS about the newest 4 barrel carb design out there. Seriously, Holley and Carter (aka: Edelbrock performer) carbs were developed before the Q and are not as advanced. Get Doug Roes book on Rochester carburetors and rebuild the thing. That book was my first introduction to carburetors and got me through rebuilding the Q on my Camaro.
The divorced choke is, IMO, the best choke system out there, so definately get that working. My Caddy and Nova both have that style and it works beautifully. The electric choke that I swapped onto my Camaro OTOH gives me fits. In cold weather the electric choke cools off too fast being a bit further away from the motor and it's always kicking the motor back onto a high idle after a short stop. Having the choke coil hugging the motor keeps it at the temp it should be.
Once you get the Q rebuilt and tuned (not a hard job) they are the most transparent carbs out there. From behind the wheel it is the closest thing to fuel injection. It will bog for an instant if you ram the pedal to the floor on a dead cold motor (duh) but aside from that it just goes.
The coil choke that I ordered should arrive any day. However, I'm fairly confident it's the wrong one after the above post. The good news is, I've found another (used) one on eBay and am going to grab that up.
I actually bought Doug Roes book last week! So it's good to hear someone else tout it as a reliable reference. I've read through nearly the entire thing and need to do so again.
I have re-thought my plan to replace the Q-Jet and am now planning on rebuilding it myself (once it gets warmer). For now, I just want to get it complete and working. The car does run very well once it is warm. So I'm not having any carb-related problems at the moment. But it sat for years and fuel seeps down the sides while it's running. That just isn't safe.
Yes! I don't have it on yet, but I did manage to find one in a salvage yard. It is in reasonably good shape for 36 years. It is mostly rust-free and all of the parts move. In the mean time, I cobbled up a counter-weight that I can hang on the primary air flap when starting the car cold. It's amazing how well that works.
I haven't put it on the car yet because I have one piece of linkage that will require partially dismantling the carb (it was just flopping around down inside the carb housing). So I've decided to go the whole nine yards and rebuild the carb as long as I have to get into that level of detail. I ordered a rebuild kit, which showed up last week.
And hell, while the carb is off, I might as well take the intake manifold off, shot-peen it, paint it and replace the old seals. So I've effectively turned my choke replacement into a reasonably major project.
The weather here has been unseasonably warm (40's). I just have to find the time away from work and home life to get out there and start pulling everything apart. January is a mess with no real free time on the horizon, so I'm looking at February for beginning the autopsy.
I actually ended up with both books. I spent the winter reading, learning and tracking down parts. I finally pulled the carb this week and started the rebuild process. So far, it's going really well. But I would have been in trouble quickly if I hadn't read those books first. Knowing the proper order in which to take things off and put them back on has been invaluable.
Hopefully, I'll have that project wrapped up later this week or over the weekend and will get to find out how well (or poorly) I did.