vapor lock help!!!

[ponyboy33]

I have a 69' mach 1 fastback that seems to be vapor locking. i changed the fuel filter and i changed the fuel pump last year so i know that it isnt that..i was just wondering what i can do to rid my car of the vapor locking. thanks a lot guys!!

 

[GDTrumbo]

Is the fuel line routed from the pump, up the front of the block near the water pump & such to the front of the carb? Kinda hot through there.
You might try re-routing the fuel line away from the engine heat.

GT

 

[ic237]

You might want to try this:
Check the filter screen after the fuel filter. You have to remove the top of the carb to get to it. It got me good, Same symptoms as vapor locking.

 

[2+2GT]

Is the carb bolted directly to the manifold, or is there a spacer? Is it an iron manifold, or aluminum?

 

[ponyboy33]

hw'fihw3rifh

there is a spacer and it is a aluminum intake. also it does it off and on and seems to right its self. frustrating! i have no idea what it could be. changed fuel filter. blew out gas lines. it isnt getting real close to hot objects (gas line) adjusted carb. and timing. it will randomly start doing it and randomly stop.

 

[rbohm]

check the fuel sock in the tank, it may be plugged up, also check the rubber fuel line from the tank to the steel line as it may be drawing air into the system. had that issue with my olds a few months ago.

 

[ponyboy33]

well blowing the line and tank out would have taken care of the sock. and it is sparatic. it does it randomly. which i weird. and to the air getting in the hose, that hose is pressurized and no gas is leaking out so no air could possibly be going in.

 

[rbohm]

well blowing the line and tank out would have taken care of the sock. and it is sparatic. it does it randomly. which i weird. and to the air getting in the hose, that hose is pressurized and no gas is leaking out so no air could possibly be going in.

the hose from the tank to the steel feed line is NOT pressurized, and just because there is no gas leaking, doesnt mean that air is not being drawn into the system. as i have said i went through this with my 77 olds. no gas was leaking, but the hose was indeed in bad enough shape to allow air to be drawn into the system. as for the sock, just because you blow out the hose into the tank doesnt mean the sock isnt going to pick the junk back up when the pump start to draw a vacuum again. you have to pull the sending unit and check the sock to be sure. you are making false assumptions here.

 

[ponyboy33]

if it was doing either of those what would cause it to right itself? it seems like when it first starts doing it it is not as severe but the longer you drive it when it is doing thaat the worse is gets.

 

[ponyboy33]

i really gotta fix this before this weekend can anyone help? any ideas? thoughts? when it first acts up it hesitates slightly and if i continue to drive it after it acts up it just gets worse and worse till it constantly does it. u can maintain the same speed you were driving but it wont really let you accelerate through it. it will sometimes just right its self within a minute or so. i am just stumped.

 

[ponyboy33]

it is almost as though it is only firing on 4 cylanders

 

[tx65coupe]

How old is the gas tank? Maybe it is full of crud that is making its way up to the carb.

 

[ponyboy33]

its the original gas tank i believe but i drove it last year also so i dont see why it would start doing it now..

 

[pabear89]

Check or replace the 3 rubber fuel lines to insure they are not cracked or loose clamps allowing air in.
1. At the tank
2. Under the drivers side floor
3. From the fuel line to pump

If they are all new, its possable that the tank screen s collecting enough crap to starve the flow to the carb.

 

[TeamEntity]

take a clean gas can with about 2 gallons of gas. and just have your pump pull from that. if it will do it at idle and at least under a load. See if it is better or same. If the same well its not from the tank up to the pump. Could be pump, could be filter in the carb, could be the carb. or ignition. If it does not act up then you have to start at the sender and work your way forward.

 

[ponyboy33]

well the accelerator pump is not working in the carburator. would that cause the problem? would rebuilding it fix that problem?

 

[ic237]

well the accelerator pump is not working in the carburator. would that cause the problem? would rebuilding it fix that problem?

I dont think its really the pump. You would have a reall hard time getting the engine started without it, The pump may not work right if the fuel bowl is empty or partially empty. I am assuming you have a stock carb. You should really take a look and that small piece of screen under the needle seat, if its clogged it will cause an empty bowl.

 

[ponyboy33]

its an edlebrock after market carburator

 

[Platonic Solid]

My Vote is your gas is going/gone bad and/or you got crud in your tank, but you don't seem to want to hear that.

 

[68RCodeConv]

Your gas cap vent may be blocked. The next time it happens remove the gas cap and see if there is a vacuum in the tank.