Hello, All !

my 1986 f150 5.8 (351w) with an edlebrock carb 1406 and duel fuel tanks. both tanks opperate fine.

Keep in mind! before the bogging, I had a automatic transmission problem when in drive, trans was slipping, so I only used it around town and drove in 2nd gear. ran fine for several weeks driving in 2nd gear.

ok! here's the problem and what I've done sofar.

at first the truck would'nt start. I checked to see if it had spark. Spark ok! I then removed the fuel line from the carb, to see if I was getting fuel to the carb. I cranked it until I just about killed the battery, to find that no fuel was getting to the carb.

So, I replaced the inline fuel filter and mechanical fuel pump! (hurray it started). Took truck for road test, while driving, it booged out as if it where running out of fuel, so I shifted into neutral to regain idle, then shifted to drive and drove several feet and it bogged again. So now it's back to the drawing board? I tested the vacume on the new fuel pump reading was 6 psi, this is good. I then removed the tiny screen that was in the fuel inlet of the edlebrock carburator, and it was dirty in 1 spot, so I just took it out and reconnected the fuel line. took it for a ride the same thing happened "bogged out" I then did a volume test which proved to be ok ( 1 pint of fuel in approx, 20 -25 seconds).




So now, I'm thinking tune up! did the tune up. Replaced plugs,wires,dist cap and roter, also replaced the ignition coil ( coil was arcing) did'nt notice that till nite time. Checked pvc valve it was ok, had good vacume. the only thing that puzzeled me was the egr valve there where no vacume tube connected to it, and no sucsion, but next to it was a vacume hose not connected to anything but the intake manifold under the carburator. I plugged the hose, the engine ran smoother. I think it was connected to the thermactor system, which is disconnected. So I unplugged the vacume hose from the intake manifold and connected it to air control valve on the thermactor system, it ran the same smooth.

So Now! I take it for a test drive, it seemed to be running better I was able to drive for a longer period of time, and then suddenly it started bogging out again.








Could it possibly be: " at this point I guess anything is possible"

the fuel strainer screens or needle and seat assembly could be clogged, which is under the air horn assembly?

OR:

Can it be the transmission not fuctioning properly, that will cause the engine to bogg out?

Thanks for any advice.

Al

 

a blown modulator in the trans , if its vacum, sometimes they are overlooked during a rebuild, , and possibly the screen in the gas tank. a poor mans fix for this is to blow air back thru the fuel line that attaches to the fuel pump. if it does this only after a good warm up , I would check for temp . controlled vacum sources, based on your no fuel condition , im leaning toward the tank bring the problem ,good luck ,bob

 

Thanks Bob, it was the trany module

I found out 2 weeks ago it was the trans module. When I pulled the vacume hose off trany module, oil poured out, replaced the module and whala!! no more bogging.


Al

 

way cool