Hello all!
I have an Edelbrock 1406 on my 86 F-250HD. I hooked up everything a few months ago, tuned it, and I was happy with the performance gains. Then the cold weather hit! I adjusted the choke to compensate for the cold. So I would go out in the morning, mash the go pedal, the choke would engage, but the truck would die 2 or 3 seconds after the engine fired up. I just figured it was because the oil was a little thick from the -16 and -17 temps we were having because I could always turn the key and it would fire right up again and rev up with the choke operating just fine and shut off without any problems or sticking.
Now, the choke quits working without any reason. I can take the air cleaner off, loosen the torx nuts on the choke housing, turn it a little and it will work fine for a few days and then (poof), no choke again. I took off the Holley 4180 I had on it and hooked up the Edelbrock's choke off of the same wire that the Holley had. I was wondering if it could be a bad connection or if it could be the thermostat spring in the choke itself. Thank in advance!

 

It may be a bad ground to the spring, that's about the only thing I can think of.

 

When you say the choke quits working without any reason, are you saying it doesn't set when cold or it doesn't release? If it doesn't set and you have the choke housing indexed according to spec the choke linkage or the air valve is probably binding.The choke coil spring sets the choke and then releases as it heats up. A bad ground or no connection should not affect the choke setting when cold. What a bad connection or ground would cause is the choke not releasing. Are you sure you have the air valve clearance and high idle speed set to spec? Typically if the air valve is not being set correctly will either cause the engine to load up or to run too lean either of which will cause the engine to die. Idle speed needs to be set properly as well since a cold engine isn't very efficient and needs higher idle speed to keep running until the engine starts to warm up and to compensate for the richer fuel mixture caused by choking.

John

 

When the choke stops working, it won't set at all. I have good clearance around the choke housing, but even if I try to engage the choke by hand, with the air cleaner off, it won't do it. I put the carb on in September and the choke worked fine until a couple of weeks ago. The weather here is a little goofy lately as it will be around 60 one day and 32 the next. I don't know if that has anything to do with it, but it seemed to work when the weather was more stable. Any ideas?

Dan

 

Are you sure that the choke spring is not installed backwards or that isn't broken or slipped off the engagement tab in the choke housing? Have you metered the electrical connection at the choke to make sure that it only gets 12v when the engine is running and not that it may be getting energized all the time? Can't undrestand why it worked before and now fails other than these items.

John

 

One thing I forgot to mention is, when I loosen the torx nuts on the choke housing and move the cover from it's original position all the way froward and back to the original position, it sets the choke back to where it was and it will work for a couple of days and then with no warning, it will stop working again.
I'm going to take the choke housing off tomorrow and see if I have an obstruction inside there. Any ideas what else it could be?

Dan

 

Sounds to me like the choke linkage is binding someplace. Remove the cover and operate the choke by hand to make sure it moves freely. If it is OK then reinstall the cover and index the cover. Again while holding the accelerator off of the fast idle speed cam move the choke linkage to see if it binds.

John