Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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.

Re: Carb gurus needed inside
 

thanks- and how would I check for that?

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

stock
no
only owned the truck for a week

Re: Carb gurus needed inside
 

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.

Re: Carb gurus needed inside
 

ya'll are awesome- thanks so much!

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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

Re: Carb gurus needed inside
 

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.

Re: Carb gurus needed inside
 

So... what did you find out?

Re: Carb gurus needed inside
 

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.

Re: Carb gurus needed inside
 

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...

Re: Carb gurus needed inside
 

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