carb help on new to me suburban

[stretch86]

I recently purchased a 86 c10 suburban and being in the rust belt its actualy in pretty good shape. The frame is solid but body does have some rot nothing i cant handle though. Anyways on to the carb the truck runs rough at start up if its cold once warmed it runs ok but stumbles and hassitates when give it gas. Also theres three lines on carb that arent connected two are plugged and one has nothing connected to it heres a pic.

[enaberif]

First replace that vac line that goes to the pcv as it should not be collapsed like that.

Second go to your local auto store and get a pack of vacuum caps and properly plug those open ports and the other one with the bolt in it and nail.

The vac ports on the thermostat housing looks like someone tried to remove smog equipment and didn't block off stuff either.

With open vac ports that truck is going to run like an absolute turd.

[fxrsrider]

won't hurt to run some SeaFoam through the fuel system either.

[enaberif]

won't hurt to run some SeaFoam through the fuel system either.

I don't recommend this as sometimes the crud in the engine could be what keeps the seals and such from leaking.

[stretch86]

I ended up putting regular carb cleaner in gas ive heard to many bad things about seafoam so i try and stay away from it

[stretch86]

Also should i cap just those three ports or the ones near thermostat also

[enaberif]

Also should i cap just those three ports or the ones near thermostat also

Those should be activated with vacuum which means there should not be any vacuum coming out of those so I wouldn't worry about them. Start with blocking off the ones on the carb and fixing your pcv vac line and seeing how the truck runs first.

[fxrsrider]

won't hurt to run some SeaFoam through the fuel system either.

I don't recommend this as sometimes the crud in the engine could be what keeps the seals and such from leaking.

The trick to SeaFoam is a little bit at a time....guys on YouTube and such pour the stuff directly into the throttle body.  BAD IDEA.  Others put 1/2 to a full bottle in the gas tank. BAD IDEA. 

If you put about 1-2oz in the gas tank overtime you fill up......then you will effectively clean your entire carb and valve train.....the "gunk" will get spit out of your exhaust.  Just keep doing it until the bottle is empty and you will see the difference.

You don't have to use SeaFoam......just make it a point to fill up for the next three months with Chevron fuel (which has Techron, which is just like SeaFoam and generally stocked right next to SF at your Auto Supply Store)......both your valve train and carb will get cleaned out sufficiently.

Between SeaFoam/Techron and Marvel Mystery Oil.....I've brought dead motors (V-twins) back from the dead.

[stretch86]

Heres an update last night when got outta work i started truck as usual and noticed it had a higher idle then usual then after 7 or so minutes of letting it warm up it bogged out and stalled. Tried to restart it and it sounded like wanted to fire but didnt then after 5 Minutes it finaly fired up and i went home. Today i capped off vacuum ports on carb changed plugs rotor and distributor cap as well as fuel filter. Went to start it and it started stumbling instantly and stalled tried to restart it and was doing same thing as last night. I took cover off carb pulled linkage and saw gas go in carb checked for spark on an old plug and was orange not blue. So my question is could it have been the coil this whole time or what else should i check.

[enaberif]

Heres an update last night when got outta work i started truck as usual and noticed it had a higher idle then usual then after 7 or so minutes of letting it warm up it bogged out and stalled. Tried to restart it and it sounded like wanted to fire but didnt then after 5 Minutes it finaly fired up and i went home. Today i capped off vacuum ports on carb changed plugs rotor and distributor cap as well as fuel filter. Went to start it and it started stumbling instantly and stalled tried to restart it and was doing same thing as last night. I took cover off carb pulled linkage and saw gas go in carb checked for spark on an old plug and was orange not blue. So my question is could it have been the coil this whole time or what else should i check.

Spark needs to be bright blue and if its not then you need to look at your coil or ignition module.

[stretch86]

I had said it was orange and not blue i ended up getting new plug wires and a coil. then ill go from there

[stretch86]

Im not new to carbs im just new to them with trucks as ive always had fuel injected but the same principles apply to any gasoline engine

[stretch86]

I put new coil and wires on it now it wont stay idling if i have foot on gas pedal a lil itll run fine with out elctric choke hooked up and with choke plate open. When i have choke connected it keeps bogging out and runs like crap. Any ideas whats going on could it be fuel pump or carb outta wack

[enaberif]

I put new coil and wires on it now it wont stay idling if i have foot on gas pedal a lil itll run fine with out elctric choke hooked up and with choke plate open. When i have choke connected it keeps bogging out and runs like crap. Any ideas whats going on could it be fuel pump or carb outta wack

I'm going to say there is a lot wrong with this truck and it was probably made to run with horrible vacuum leaks. You are essentially going to have start from scratch and retune everything

[stretch86]

Awesome i did notice plug wires were crap and one was torn badly. I have no clue how to tune a truck carb its a lot different then a atv or motorcycle. how do i do it or at least what are stock settings and where are the screws etc i should be turning.