my broncos driving me crazy

[Kelpsniper]

Well ill start by saying it runs when it wants. At idle it will run good for about 5 mins then the engine will try to cut out or some times it will work through the short hick up and run another 5 to 10 mins before it does it again. As soon as you apply a load to it she dies. Sometimes it will run good for about 20 mins then die. I have replaced the fuel filter , adjusted the carb which isnt to old maybe 2 months old its a edelbrock. Also replaced the fuel pump.Filled both the tanks with premium gas. spark plug wires are also new. It has a electric valve switch for the gas tanks. which looks brand new. It has a upgraded pertronixs point system and a cranes cam HO coil. I ve had the car a total of 2 months now and its driving me crazy now lol. Any suggestions thanks in advance....

 

[JLBachs]

This is a long-shot, but depending on how old your bronco is, someone may have replaced vented gas caps with the newer-style non-vented ones. You might try just taking the gas caps off and see if it comes out of it. Also the bowl vent on the passenger side of the Edelbrock needs to be able to vent -

 

[marty]

run through all the basics. do you have good fuel pressure. sounds to me like if it runs for a few minutes it is using up the fuel in the bowl(s) of the carb and then runs out. have you checked you fuel pickup screens. when you go to acccelerate and it stalls it sounds to me like you are not getting a shot of fuel from the accelerator pump. with the engine not running look down the carb and open the throttle wide open a couple of times. you should see 2 steady streams of fuel being shot down the throat of the carb. if not you are starved for fuel or have a bad accelerator pump in the carb. you say it has a new fuel pump are you sure the eccentric on the cam is not worn out. once you get it running for a few minutes have you tried to advance the timing a bit or checked it with a light. these are all basic things to try. just don't hang your face over a carb with the engine running.

 

[diestech74]

I had similar problems that I chased looking for a carb problem since it was my first exp with tuning a carb it turned out to be the coil. finally hooked up an in line spark checker & noticed it would run regular for several a while then go into a erratic pulse of spark then return to normal in a unpredicable cycle.

 

[luderchris]

I had similar problems that I chased looking for a carb problem since it was my first exp with tuning a carb it turned out to be the coil. finally hooked up an in line spark checker & noticed it would run regular for several a while then go into a erratic pulse of spark then return to normal in a unpredicable cycle.

Had this same issue on a CJ8 years ago. Went over everything and it turned out to be a bad coil.

 

[Kelpsniper]

OK well i replaced the coil and it still did the same thing. I also replaced the gas cap with a vented one and it seem to be running ok at the moment. I also took the top of the carb off and blew air in the jets both primary and sec. what else could it have been. i noticed that some times my clear fuel filter is full and some times it has just enough to fill the screen whats that is it the carb opening up for fuel or is it suppose to be full all the time? Thanksfor all the reponse