1970 c10 350 dies as soon as i hit 40 mph
 

Ok so i just bought this truck. The vin states its a chevy c10 3/4 ton chassis. But it is the full time 4wd. It just had a transmission rebuilt before i bought it. It has the chevy 350 with a th350 behind it. I have replaced fuel filter and spark plugs (they were fouled pretty badly). I also timed the engine to a 10* advance. I was gonna rebuild the carb but i broke one of the carb mounting bolts and didnt want to risk breaking the others until i knew i could replace the whole intake and carb if i broke them all. It has brand new battery and cables as well. What is going on is at first before timing it and replacing spark plugs it would run at idle and low speeds just fine but then i would hit 25 mph and it would bog down and die. I timed it and replaced spark plugs and now i can go all the way to 40 and it just bogs down and dies. Its as if The fuel just stops sending to the carb. I dont have much experience with carbed engines and just want some more experinced opinions on what is going on.
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

Sounds like the sock on the fuel pickup in the tank is plugged up. You say you replaced the filter in the carb. Sometimes someone puts an inline filter in the line from the tank to the pump. Check to see if there might be an aux. filter underneath.
George

I actually replaced the inline fileter there was no filter in the carb. And i dont think it is the stock carb either i dont know if that makes a difference, it is still a 2bbl carb.
Posted via Mobile Device

Do i have to pull the fuel tank to clean sock on the fuel pickup?
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

No!
But do some other things first.
Disable the ignition so it won’t start when you crank it over.
Pull the fuel line off the carb, stick it in a quart jar and crank it over. It should fill the jar in 30 seconds or less.
Let us know how that works.

Also post some pics of your motor for us.

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

Could be a crack in your fuel line sucking air. I had it happen to me once on a 69 442. It would run fine at low speeds but if I brought it off the line it would go 3 or 4 car lengths and cut out.

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

What carburetor, and what ignition (stock points or HEI)? There are many things that can cause this. Let's just say you creep up on 40 MPH. Does it still happen, as opposed to a full throttle run up to 40 MPH?

What is the best way to disable the ingnition?
Posted via Mobile Device

I was thinking about replacing the fuel lines anyway so maybe i will just replace them and not worry about looking for a crack.
Posted via Mobile Device

Im pretty sure its a rochester 2bbl carb. And i think it does have the hei distributor. Yes if i creep up to 40 it still dies vs doing a full throttle pass. No matter how i feather the gas as soon as i hit 40 it basically shuts off. Sometime when i lef off the gas for a couple seconds and then tap the gas a couple times the engine comes back to life but runs rough for a little.
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

Depends on your distributor type.
Points type just pop the coil wire off.
If hei unplug the power clip from the cap.

Pics of what you got would help.

I can get pictures tomorrow.
Posted via Mobile Device

Ok here are some pictures of the distributor or carb. Sorry it took so long just got busy and forgot. I drove it around town today and it runs amazing as long as im going Under 40mph.
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

You have HEI. To disable it, just unplug the terminal marked BAT.

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

That carb looks like it may not have ever been off engine, or apart. Could be part of problem...If it's had any ethanol gas run through it, that could be a problem...

Ok cool thank you.
Posted via Mobile Device

I have a buddy who took a quadrojet off of his old 350 he has the carb and intake he will sell me for 50$. Is that worth is to buy that and put it on vs trying to rebuild the one thats on it?
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

That might be a choice after we diagnose your problem better.
Give us some more pics. With the air cleaner off. Show us both sides of your carb. And the bolt you mentioned is broken.

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

weights are stuck under the rotor and causing the motor to die out, .

Ok got some more pictures. Ill be working on it today and tomorrow as this is my weekend. After that one bolt broke i did not try and take any of the others out. Would it help if i got a video of what was happening as it dies?
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

That missing bolt shouldn’t be a problem. There were 4 on your carb. Originally on older intakes there were only 2 bolts holding the carb on.
Sure a video won’t hurt.
Your pics don’t help much.
Try some that aren’t closeups.

Ok hopefully these are better
Posted via Mobile Device

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

Carb swallowed some of that orange goo holding the jury-rigged air cleaner hold-down?

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

Much better pics!
Some very laughable stuff you got.
Carb linkage and cobbled air cleaner stud to name a couple.
First thing I’d do is put in more timing. Bump it up to 15 initial.
If that doesn’t improve it then check the fuel pump output.

Re: 1970 c10 350 dies as soon as i hit 40 mph
 

A can of carb cleaner would probably help a lot , Plugs ,wires,etc, . Join one of the local car clubs in your area .They could help you out with the hands on stuff . :chevy:


Here are a few .

https://www.google.com/search?q=+Gra...firefox-b-1-ab