1986 Ford Econline 350 - Loss of power small hill
 

Help!!! I inherited a motor home that has sat a while. When i got it there was a can of starting fluid inside the cab and the carb vent assembly off. I reassembled and started it up took for drive. Ran terrible. Since that first drive I have given a tune up and replaced a short list of items as precautionary using this site along the way for direction.

Vehicle: 1986 Ford E-350 chassis / Motorhome
Engine: 460
Intake: Holley Carb 4180
Emissions: Yes

Replaced: EGR
Both Oil Pressure Sender Switches. (one for dash/one for fuel pump power)
Fuel filter at carb and fuel filter in rail.
Battery
Plugs/wires/cap/rotor
Air filter
Oil and Filter
Carb Rebuild (Fixed issue with secondary floats stuck, secondary diaphram ripped, and blown power valve)
Replaced EGR vent tubing
Replaced short vent tubing on front of intake manifold.
New gas line from tank to built in generator
New locking gas cap (doesn't change performance with new or old cap in place)
Had Mechanic adjust timing

Now the beast runs great....except for small hills. Up any hill id bogs down and wants to die. Thought maybe the float levels but i can adjust to almost flooding and issue persists or run float bowls lean and still get the same result. Not the floats.

I drove with vacuum gauge hooked up and all seems fine but I don't really know what I am looking for.

I feel like I am starving for air/fuel or the timing gets all out of whack when I get to the hill. If I ease off the pedal I may make it far enough to turn around before it dies. Going back down the hill or on the straights it is a bat out of hell.

Thoughts.... Coil, ignition module? Or could it be the fuel pump cutting out on a hill? There seems to be plenty of fuel in float bowls on hill.

Helpful advice appreciated.

Sure sounds like you're starving for fuel under a load. Had a similar issue a while back and it was a dirty frame rail fuel filter.

If you have a lot of sediment in the tank the filter could be dirty again or sediments could be blocking the pick up sock inside the tank.

Beyond that wondering if it could be a problem with the power valve? As the demand for fuel exceeds the capacity of the main jets, the powevalve opens to supply more fuel.

BrnFree - Thanks for input. As originally stated the frame rail filter was just replaced. I will check filter again but it is new and there was no contamination in the line that I can see in the filter bowl.

The power valve is also new in the carb rebuild and works on straight away. Carb is dialed.

Tested fuel pressure in driveway and it is good but unable to test on a hill.

Dura Spark II - Coil & Ignition module are both stock and are next on the list. If that is not where I am losing all power on hills I am dropping the tank to inspect pump even thought I have solid pressure in my driveway. Mfrrrr!

Another thing you can try is disconnecting the oil pressure fuel cut off switch and jumping the plug. If that solves the cutting out problem you should investigate the oil pressure.

Also wondering if you have the hot fuel handling parts in place. It consists of a metal vapor separating bypass valve near the distributor. It looks like a little metal filter and it has three fuel lines attached to it; fuel in, fuel out to the carb, and a return line. If this has been hacked up or removed It could cause vapor lock or other issues.

Brnfree - We are on the same page.

Because of its age I replaced the little oil pressure fuel cut off switch. I have also tested power at the fuel pump with a solid power delivery during crank (solenoid power) and while running (oil pressure sending switch power). All is good.

Yes, that little three-way fuel evap return/hot fuel handling part is in place. I was trying to find one local but no one sells it. I found it online for $70 bucks but can't imagine it would go bad as there is not much in there (screen/3 holes). It use to cost $8 bucks now its $70-$120 because no one has it.