mw78c20
Junior Member
- Joined
- Dec 26, 2022
- Posts
- 2
- Reaction score
- 0
- Location
- western canada
- First Name
- mike
- Truck Year
- 1978
- Truck Model
- c20
- Engine Size
- 5.7L 350 V8
so ive never been happy with the carb on my c10, it needed a lot of babysitting once the temp dropped below freezing and bogged a lot under acceleration even once warm. this is just a farm truck so its not a big deal but ive just gone through the process of swapping it to another one i got from a classified ad and.. generally speaking i'm pretty happy with the result, but ive already found a couple of missing parts so just hoping for a sanity check here from someone who knows qjets.
1) this "new" carb has an electric choke on it, which i haven't hooked up yet and don't know if it's operable or not. but generally speaking, if an electric choke is installed but not powered, will it essentially just hold the choke on 100% all the time? i assume it must, because i've had to use a screwdriver to hold open the choke plate or it just floods itself. i also noticed there is only 1 rod connected to the secondaries and
2) the old carb appears to have had 2 throttle return springs, one inside the other, connected to the throttle pump. I noticed this when looking at one of my reference pictures from the beginning of all this and could clearly see it was one inside the other. the thing is, when I hooked it back up this way I'm now having the gas pedal get 'stuck' open which is super annoying and probably not great for the truck. it seems to happen LESS when I have just 1. is the use of 2 separate springs in unison like this normal or for any purpose?
3) even with the choke forced open, i'm finding this carb way better for cold starts than the last one. it seems really eager to fire up even after sitting overnight. it also seems a lot more responsive for driving as well i'm kind of amazed at how different it feels. of course, it's not winter temps yet, but so far i'm quite happy. i've noticed though that after the engine has warmed up some, if I switch it off even just for 15-20 seconds it will crank and crank until I put my foot about halfway down then fires up and runs ok. i guess this is fine if thats just what it wants but am not sure if this is indicative of a bigger problem. may have more on this over the next couple weeks as I use it more.
1) this "new" carb has an electric choke on it, which i haven't hooked up yet and don't know if it's operable or not. but generally speaking, if an electric choke is installed but not powered, will it essentially just hold the choke on 100% all the time? i assume it must, because i've had to use a screwdriver to hold open the choke plate or it just floods itself. i also noticed there is only 1 rod connected to the secondaries and
2) the old carb appears to have had 2 throttle return springs, one inside the other, connected to the throttle pump. I noticed this when looking at one of my reference pictures from the beginning of all this and could clearly see it was one inside the other. the thing is, when I hooked it back up this way I'm now having the gas pedal get 'stuck' open which is super annoying and probably not great for the truck. it seems to happen LESS when I have just 1. is the use of 2 separate springs in unison like this normal or for any purpose?
3) even with the choke forced open, i'm finding this carb way better for cold starts than the last one. it seems really eager to fire up even after sitting overnight. it also seems a lot more responsive for driving as well i'm kind of amazed at how different it feels. of course, it's not winter temps yet, but so far i'm quite happy. i've noticed though that after the engine has warmed up some, if I switch it off even just for 15-20 seconds it will crank and crank until I put my foot about halfway down then fires up and runs ok. i guess this is fine if thats just what it wants but am not sure if this is indicative of a bigger problem. may have more on this over the next couple weeks as I use it more.
