HELP!! 78 fj40 MOTOR STALLING OUT OVER BRIDGE!!

[aw2phillips]

hi IH8,
I have a 78 2f that is spudering out and acting like its going to dye or run out of gas when i cross over a major bridge here in san diego. I dosent act like that or dye out any other time. Im wondering if this is a carb issue?..... when i start it up in the moringing she spuders win i give it gas, but gets better when the motor warms. The other thing that make me think its a carb issue is when i press the gas pedal fast the motor boggs down. So what should i do? Please shoot me some answers IH8 member i have to go to work tommorow...HAHA.

Thanks,
jeremy

 

[1sttime40]

I would check for vacuum leaks before tearing into the carb.

 

[Biscuit]

x2 on the vacuum leaks. When you quickly press down on the gas pedal you are opening the throttle butterflys at the way reducing your vacuum. If your vacuum is weak to start with, this will cause it to drop to unacceptably low levels.

This symptom can go away as the motor warms up as all the metals expanding can temporarily hide some leaks that are present when the motor is cold.

Since a '78 is emissions controlled in CA, you have all sorts of places a vacuum leak could be coming from. I'd start by checking the vacuum lines.

 

[aw2phillips]

Ok right on, i will do the old brake cleaner trick(on a cold motor) tommorow. Im still confused as to why the motor will violently act like its out of gas and pretty much dye ONLY as i go !UP! the bridge? If the bridge us any bigger i would stall! if it is a bad vaccum leak wouldnt it act this way all the time?
p.s. The motor has had all the smog gear pulled off!
Thanks
jeremy

USN

 

[byrd_hntr]

I second checking the vacuum lines. When I brought my 77 home it would barley run, turns out the PO has some manifold work done and they forgot to tighten the carb down and it had a terrible leak at the carb base. Torqued the carb down and it ran perfect. Also take a look at the fuel window to see if the gas is at the proper level when its started. This will tell you if the float working properly. A clogged fuel filter is another easy thing to check.