trouble with my 83 C10

[fris_94]

I got a 83 Chev C10. L6 4.1L 250. I don't know a whole lot about trucks and luckily I don't have many problems with the truck, except for the fact that I can't get the choke to go off. I was told that the vacuum pump is broke. Wondering what I can do here to fix the problem. I don't know if the vacuum pump can be replaced or where I can find one for the truck. Any bit of help is greatly appreciated.

[86swb]

I wish I had some answers for you but I do not know. But would like to welcome you to the board from Western Kentucky.

[crossy]

fris, welcome eh.
second , your ENGINE is your vacuum pump, LOL, so if thats broken your not worried about the choke anymore :-).
your carb Should have a small, round shaped canister(pod) on it with a very short vacuum line that runs from a port on the carb base/body to the pod. The pod is usually white plastic but could be cad plated metal. the pod is a vacuum pull-off for the choke. there is an arm that comes out of it with a long slot and hooks to the choke linkage. first pull that vacuum line off while it is running and make sure there is full vacuum there. and make sure that arm goes in and out as the vacuum line is disconnected. if not you need to replace the vacuum pull-off for starters . from there you will have to tell us wether your particular carb uses an elctric choke(an 84 should) or if it is uses manifold heat. check the pull-off and get back to us.
PS- an electric choke uses a silver dollar sized black plastic cover on the side of the carb where as a thermo stove choke uses a wound bi-metal spring down in the manifold just below the carb base with linkage running upward. crossy

[fris_94]

thanks crossy. I see what i can do when i get home from school. hopefully we can get somewhere with this. now that i think about it more and more i think that it is the vacuum pull-off that needs replacing. but ill check it out anyway.

[fris_94]

i just checked the truck and i got plenty of vacuum in the line and the arm can move back and forth. Usually what I have to do to get the choke to go off is wait a while after I started the truck up then give her a good shot of gas and the choke will go off. Anyway, it does have an electric choke.

[crossy]

Fris sent me this .
i was just out at my truck looking at the choke. i was looking at the arm on the pod and how its all connected to the choke. i pushed the choke down with my finger ( the truck was off ) and now it seems like the choke is loose. it seems like the arm from the pod is slipping through the linkage to the choke. just wondering if something is loose or what happened.

the arm coming out of the pod will always move freely but should move in and out as the vacuum line(while running) is connected and disconnected. thats what tells you the diaphragm inside is good.

check it with engine stone cold and with the aircleaner off. Push your pedal to the floor once. that should cause the choke plate to be fully closed off. when you start it the pull off pulls it just enough open to let some air by. as the choke coil heats (12 volts) it SHZOULD put more pressure on the linkage that it opens the plate further. You DO have to touch the pedal though for it to go open because the coil can't overcome the mechanical'step' that are on the linkage. There is a quarter round cam that has steps the choke linkage also has a cam with a screw in it that rests on steps, and little by little the choke is suppose to open. If the choke stays closed like yours is ther is a GOOD possibility that the thermo coil inside the black thingy is bad. I've had lots of trouble with them thermo coils over the years. on SOME carbs there is linkage that actually passes thru the body of the carb to connect to the cam below and there is a possibiltiy that it is disconnected.
PS- why would you need a choke in Canada :-)

[fris_94]

2 questions. is the thermo coil hard to change and is it hard to track one down? also what i meant by "it seems the choke is loose" i meant that the choke is easier to push down than it was.

[crossy]

black plastic may have 3 rivets instead of screws. rivets get drilled out and then use like #6 sheet metal screws. the bimetal coil is more expensive than it should be $20-40 , and Yes it can be hard to find a guy behind a counter that even has a clue about this part.

[fris_94]

i just went out and started the truck. i must have did something to the choke today because when i started her up the choke didn't stay closed. i can flick the choke flap back and forth with my finger. before, if the choke was all the way down, like it is now, you would have to force it up, and if it was up you would have to force it down. im always curious because this choke had been haunting me for a long time and i just want it fixed.

[crossy]

http://www.partsamerica.com/ProductL...oke+Thermostat

told you they can be high $$ . ;-(

[crossy]

gotta find out where it is disconnected then. the links are only held on with tiny hairpin clips and they are easy to knock off. one link goes behind the black plastic and goes thru it in the back and connects to the thermo coil. sounds like that one came off to me.

[fris_94]

ill see what i can do with that link. before i can do anything i have to get those damn rivets drilled out. that seems to be the biggest obstacle right now. thanks a lot and i hope this all works out.

[fris_94]

I took a video of how my choke is acting so you can get a better feel for it. http://www.youtube.com/watch?v=-8hrcZTHBms


Also, im open to anyone else's comments about this choke....i'll take as much help as I can get

[crossy]

I'm at a loss pal, I had to wait till I got to work where I havea real modem to watch it but,the video showed me nothing except it's half open. Was the truck running? up to full temp?

Match Mark the position of the black plastic to the carb housing before you drill out the rivets.

[fris_94]

crossy, no the truck wasn't running at all but the choke is the same way when it is running. i had the rivets drilled out today but when i took off the coil i couldn't see what was let loose. i might have another look at it tomorrow cause i left my tools in school Anyway when i take the truck into the shop later on this week I'm going to get the choke look at to see if I can give the problem a definite diagnosis. When I put the coil back on I hooked the coil back on the little "handle", but the choke stayed the same. I don't think the black plastic is in the same position as when I took it off but I do know where it was so I can change that tomorrow. The truck is bad now at first because where I can't get the choke to go completely off right away, the truck is always flooding on me, she spits out black smoke, and I don't have half the power she usually do. But after driving her around a bit the choke will eventually go off and the truck will be fine. I can do with that for now but the choke will be fixed, I'm not going this winter with a bad choke. Let me know what you think about it all. Thanks.

[crossy]

OK with the truck at full temp adjust the choke, by turning the black plastic so that the choke is just barely off all the way. that will give you good 'hot' drivability. when you shut er down for the night remove the aircleaner and set it on your seat so you dont forget like i would. anyway now in the morning the truck is stone cold. flip the throttle linkage , just like you would be pushing down on the gas pedal. do this from under the hood though, and the choke plate should go to the full closed position. If it doesn't then either the thermo coil is bad or there is linkage disconnected somewhere. when you start it the choke pull off should allow it to open enough to get air past enough to run but my guess is that it won't even go full closed because your coil is bad.

[fris_94]

I think thats where I got the choke disconnected to. When I push the pedal the choke flap doesn't move (running or off). It would probably also explain why the truck doesn't idle high anymore. At first it would idle high and after a while of letting her warm up I would give her a quick shot of gas and the choke would go off. When I forced the choke down last weekend the truck wouldn't idle high at all and choke wouldn't move. I just finished talking to dad back home and he found the manual choke kit we got for the truck. We were going to put it on a while ago but we were told that it wasn't a good idea. My buddy had a lot of trouble with one. He had to be really precise with the choke or something so they took it off. Anyway, would putting a manual choke on it be a good idea. I was told its just getting used to it.

[crossy]

all I can say is that they(manual chokes) were factory installed for MANY years before stove chokes then eventually electric chokes. Many large trucks used them up through the 80's.

[fris_94]

Do you know how the throttle is connected to the choke. I couldn't get the truck started this morning so this is really starting to piss me off.