Carb gurus needed inside

[encasedmetal]

hello, I have an 85' C10 SWB with a 305/SM465. In the mornings it takes 3 tries or so while pedaling to get the truck to crank, and then while driving to work it occasionally feels as if a strong wind just hit the front of the truck-similar to if I just lightly tapped the brakes for 2 sec or so. Any ideas on what this is or how I can get my truck to crank better? It has an electric choke and the choke light comes on when cranking but I don't know much about carbs so I'm asking advice from those who do. thanks in advance

[Oberon67]

The last such event we saw here was due to a bad fuel pump. Check for a visible fuel pump leak after running the truck... a simple check, and an easy fix. Hope it's that.

[encasedmetal]

Originally Posted by Oberon67

The last such event we saw here was due to a bad fuel pump. Check for a visible fuel pump leak after running the truck... a simple check, and an easy fix. Hope it's that.

thanks- and how would I check for that?

[Oberon67]

After you've run the truck, look at the bottom of the fuel pump and see if it's wet with gasoline. If it is, that's your problem.

Pics here:

http://www.67-72chevytrucks.com/vboa...d.php?t=702943

[geezer#99]

Originally Posted by encasedmetal

hello, I have an 85' C10 SWB with a 305/SM465. In the mornings it takes 3 tries or so while pedaling to get the truck to crank, and then while driving to work it occasionally feels as if a strong wind just hit the front of the truck-similar to if I just lightly tapped the brakes for 2 sec or so. Any ideas on what this is or how I can get my truck to crank better? It has an electric choke and the choke light comes on when cranking but I don't know much about carbs so I'm asking advice from those who do. thanks in advance

Stock motor or modified?
Do you have headers?
Did it just start doing this?
Do you have pics of your carb?

[encasedmetal]

I will take a look today after work and report back- thanks so much

[encasedmetal]

Originally Posted by geezer#99

Stock motor or modified?
Do you have headers?
Did it just start doing this?
Do you have pics of your carb?

stock
no
only owned the truck for a week

[tucsonjwt]

My guess is that your choke is sticking - not opening all the way when the engine is hot and not closing all the way when the engine is cold.

Perform this check: Push the accelerator all the way to the floor once after turning the ignition to the on position. Open the hood, remove the air cleaner, check to see if the choke valve in the carburetor (aka butterfly) is closed all the way. It must be completely closed to start properly. Put your finger on the choke valve to make sure it is really closed all the way. If it is not completely closed then that is your starting problem.

After the engine is warm, remove the air cleaner and check to see that the choke valve is completely open - straight up and down vertical. If the choke valve is partially closed then that is your run condition problem.

If you are having choke trouble, I would remove the electric choke and convert to a manual choke ($12 and about 1/2 hour of work.) I converted all of my carbureted vehicles to manual chokes.

[encasedmetal]

ya'll are awesome- thanks so much!

[encasedmetal]

checked the choke cold and it was fully closed. will drive it here shortly and report back concerning a leaking fuel pump

[tucsonjwt]

Don't forget to check the choke when the engine is warm.

[encasedmetal]

found that the fuel pump was looking wet on the bottom so I'll replace it today and see what comes to fruition

[geezer#99]

Whoa!! Back up!!
Don't start throwing money at it!!
Take some pics!
There's a bunch of stuff in that area by the pump that can show up on your pump.

[Oberon67]

Originally Posted by encasedmetal

found that the fuel pump was looking wet on the bottom so I'll replace it today and see what comes to fruition

So... what did you find out?

[encasedmetal]

Originally Posted by Oberon67

So... what did you find out?

replaced the fuel pump 20$, drives alot better- seems to have more tq now. however, this morning I found gas coming from the threaded fitting that goes in the fuel pump so I'll have to address that.

[Oberon67]

Originally Posted by encasedmetal

replaced the fuel pump 20$, drives alot better- seems to have more tq now. however, this morning I found gas coming from the threaded fitting that goes in the fuel pump so I'll have to address that.

You may have cross-threaded the connection when you installed the new fuel pump; that's simple to fix. It may also be that you didn't snug the nut down hard enough. Before attempting to snug it down further, be absolutely certain that it's not cross-threaded, or you'll just make things worse.

It may also be that the fitting on your replacement pump is a less-than-perfect fit for the flare on the end of your hard fuel line to the carb. The right way to fix this is to cut off the end of the line and re-flare it, creating a new fitting. Failing that (and the repair I would do if it were me), you can slide the nut up the line and apply a couple wraps of Teflon tape over the flare, then slide the nut back down and attach as normal.

Yeah, you're not supposed to Teflon-tape these fittings, but it works.

...don't ask me how I know this...

[encasedmetal]

Originally Posted by Oberon67

You may have cross-threaded the connection when you installed the new fuel pump; that's simple to fix. It may also be that you didn't snug the nut down hard enough. Before attempting to snug it down further, be absolutely certain that it's not cross-threaded, or you'll just make things worse.

It may also be that the fitting on your replacement pump is a less-than-perfect fit for the flare on the end of your hard fuel line to the carb. The right way to fix this is to cut off the end of the line and re-flare it, creating a new fitting. Failing that (and the repair I would do if it were me), you can slide the nut up the line and apply a couple wraps of Teflon tape over the flare, then slide the nut back down and attach as normal.

Yeah, you're not supposed to Teflon-tape these fittings, but it works.

...don't ask me how I know this...

very cool, thanks. my dad is from rocky mount btw