I was on the freeway and it was fine, then suddenly it starts surging, like I was on and off the gas pedal. It does it at idle and at speed. I cleaned fuel filter and replaced the pump, no change. A few days before after I ran the front tank empty it started dying when I let off the gas and I took off the fuel filter and sprayed it with brake cleaner and blew it out with compressed air and replaced it, and it seemed to work. The day that the surge started I had passed Oregon DEQ emissions test.
1984 Ford F-250 = 351 v8-2b Carb = Borg Warner T-18 4 sp. = 2WD = Dual fuel tanks
Has fairly new coil, pick up coil, Fender mounted modulator, battery. Brand new fuel pump.
Make sure all the rubber hoses are not cracked and sucking air instead of fuel.
Cleaned fuel filter? Replace it as you never get all the dirt out. It can bet into the carb and block passages
March, 11, 2013 AT 2:58 PM
Thanks. I also read that the Fuel Tank Selector Valve could also be suspect, the front tank fuel guage stopped working recently. Not sure if the valve would cause the surging, if I cant find a cracked hose, and replace the filter (parts store didnt have one in stock, sprayed it with brake cleaner and compressed air) what should I look at next?
March, 13, 2013 AT 5:30 AM
Today I blew out the Tank Selector valve and made sure it worked. It does and isnt blocked. I looked over the fuel lines as much as I could see and replaced the clamps. No change
Tried to check timing but was so erratic because of the surging it was unreadable, but everything was fine that day.
Next I am going to look over the vacuum lines again and check the spark plugs. I dont know enough about carbs to mess around much with it although I am gonna see if it is loose.
March, 14, 2013 AT 2:58 PM
I took the distributor cap off after I went over all of the vacuum hoses and found the problem. (I HOPE)
The reluctor was spinning freely on the distributor shaft, the roll pin had broken or came out. I havent looked at it any further, will get to it today but it explains the surging and misfiring and could be as easy a fix as replacing the roll pin, but as cheap as they are I may just buy a complete remanufactured distributor and drop it in in case something else is ready to fall off the one I got.