My 1971 Mystery Machine Van(yes its awesome) has had some issues recently. I was leaving work when it idled ****tily, and barelly made it the four blocks home. Gas was dumping all over the manifold from the carb.

I took it apart, cleaned it out(it was full of silt as the tank has rust in it) and slapped in a rebuild kit. The actual cause of the leak was the ruptured accelerator pump diaphragm. So i replaced everything i could and it ran beautifully for a week, until i went to break a twenty at a gas station and it wouldnt start, and idled ****tily again. I took apart the carb twice that night trying to clean it out and to no avail. After about 5 hours of experimenting with it and other possibe issues, it ran ok for about two minutes but as i was about to victoriously sit down and drive home it just died. So i came back the next day and kept experimenting with it, and eventually killed the battery. So i had the corvair jump it over the course of an hour, and i sure felt bad for my starter. Eventually had it towed.

Sat on it for a few weeks but have toyed with it here and there. Im sure ive taken apart and cleaned that carb at least 10 times, every orfice has been blasted through.

Its symptoms now are EXTREMELY rough idle, and bogging out/ backfire when the gas pedal is pushed down with basically NO rpm increase.
Things that have been replaced in the past month:
-Ignition wires
-plugs(cleaned)
-distributer cap
-points
-condesor
-coil
-battery
-battery cables(all)

guys what can i do to make this mystery solved pun intended

straight six 240 3 speed manual

 

fuel filter?

 

fuel filter was replaced with a clear inline one

 

Timing chain jumped?

 

I have not checked, hopefully not, timing was perfect prior to issues

 

No timing chains on the 240/300 inline 6's Just a pair of timing gears. And they can be checked by pulling the distributor cap and cranking the engine. If the distributor shaft/rotor spins gears should be good. If it doesn't then you either sheared a roll pin off on the distributor drive gear or loss the teeth on the cam timing gear.

Does your carb have the metal fuel filter at the inlet of the carb? Most older Ford carbs had the metal can style fuel filter there.

You said you installed a clear filter is it filling with fuel? If it isn't you may have to check the fuel pump, fuel lines or the pick up tube in the gas tank. Also replace any rubber fuel hose with new alcohol compatible fuel hose. Old hoses can look fine but not allow flow thru. Or collapse, especially on the inlet side of the fuel pump.

Also check your hard fuel line from the tank to the fuel pump for rust or pin holes. if there are any holes in it the fuel pump won't be able to pull enough fuel up to the engine. It may also be blocked with crap.


I would also suggest replacing the spark plugs. Or at the very least make sure you are getting a good strong spark from each of them.