Need advice why my truck keeps dying
 

I just rebuilt the 250 in my 69. It runs great as long as I don't go very far. Once it warms up it dies. Like I said the truck runs great short distances. I had it bored out.040 do I need to run a different thermostat? What about a fan clutch? Is it a valve problem?

Please help... I want to be able to drive this farther than the grocery store.

Re: Need advice why my truck keeps dying
 

fuel filter? electrical? When it dies, does the truck turn over? Is it getting gas? Any more info can you give us?

Re: Need advice why my truck keeps dying
 

Yeah, need a little more detailed info on exactly what happens when it dies, and what is does/doesn't do after it dies.

Re: Need advice why my truck keeps dying
 

i would suspect coil, condensor or ign. modual when it dies check for spark while it's still hot

Re: Need advice why my truck keeps dying
 

Had the same problem with my 250 years ago.... the carb was full of junk. I pulled the fuel line that went into the carb and the filter was packed full, it would go about a mile down the road and die. I then discoverd the inside of my tank was shot from rust and dirt (reason carb was dirty.) Might want to take a look into the tank as well if you fuel filters are diry (carb and in-line).

Re: Need advice why my truck keeps dying
 

The truck kind of sputters before it dies and seems like it's losing power. It will restart easily. If I keep giving it a little gas it will stay running. The fuel filter is new. The coil is close to new. I'm wondering now about the gas tank.

Re: Need advice why my truck keeps dying
 

What about the carb? Is it new, rebuilt or cleaned? If the fuel filter is one of them clear ones, look to see if it's dirty already.

Re: Need advice why my truck keeps dying
 

both the carb and filter are clean

Re: Need advice why my truck keeps dying
 

I had another thought. Did you replace the gas cap? The earlier years (I think 67-69?) had a vented gas cap and 71 and 72 (I may be wrong on the years) had a vented evaporation system for emissions. If you recently put a non-vented gas cap on it the tank will stop sucking fuel once the air is gone. Try driving the truck around for a bit with the cap off (I would only do this with a low fuel amount as it tends to splash out going around corners) and see if that makes a difference? Did you install HEI or still have the original points?

Re: Need advice why my truck keeps dying
 

is the fuel line from the pump to carb touching the block causing the fuel to boil and vapor lock or worse yet did you use rubber fuel hose and not rogid tubing

Re: Need advice why my truck keeps dying
 

No I didn't replace the gas cap. It has a petronix ignition system in it and it checked out fine. I'm really at a loss.

Re: Need advice why my truck keeps dying
 

So it sounds like a fuel problem.Did you remove the filter in the carb?The sintered bronze one?It may be allowing fuel thru but not enough to keep going.When it dies the pressure may push more thru over a few minutes so it will start again.Just a guess.
Also,did you replace the fuel pump?Sometimes they will stop pumping after they warm up.

Re: Need advice why my truck keeps dying
 

I did replace the fuel filter it's not a bronze one but a paper one. The line from the pump to the carb is the stainless line. I'll double check and see if it's touching the motor.

Re: Need advice why my truck keeps dying
 

It could still be the gas cap. It wouldnt hurt to run it loose like 67 said they have been known to plug up. ask me how i know. it was a very expensive trial and error fix just to find out it was the cap. is the carb leaned out to much causing vapor lock.

Re: Need advice why my truck keeps dying
 

I'll try the gas cap. Should I just take it off all together and see if it runs better?

Re: Need advice why my truck keeps dying
 

No just loosen it so it can suck in air if it needs to. do it with a quarter of a tank or less. just drive it and see what happens. If it doesnt die then just replace the cap. if it does die you will know what it is not.

Re: Need advice why my truck keeps dying
 

Thanks. I'll try that when I get home. It's been really frustrating because when it runs it runs great. I'll let you know what happens.

Re: Need advice why my truck keeps dying
 

I'll be damned if that didn't do it! So far anyway that seems to have taken care of it. Now where's the best place to get a correct gas cap?lol

Re: Need advice why my truck keeps dying
 

Glad to be of service:D

Sorry, but I don't know where to get one:( Maybe autozone? Just make sure it's "vented."

Re: Need advice why my truck keeps dying
 

Glad it worked out for you. happy motoring. Lou.

Re: Need advice why my truck keeps dying
 

If you can't find a correct one, a '68 Impala cap fits, it just looks kinda strange. On the bright side, nobody's gonna steal it.:D