Odd problem, 85 F250

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Apr 11, 2008 | 10:55 AM

#16

Franklin2

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From: Virginia

I have never had the icing problem in 70 degree weather. And it also usually has to be damp and rainy. If it's 20 degrees outside, but dry, I haven't had the icing problem either.

It does sound like a fuel problem from what you describe. It sounds like the fuel system is barely keeping up. Around town it is keeping up, and when you get down on it for short bursts, there is enough fuel left in the bowels to keep it going. But it sounds like long high fuel useage is slowly draining the fuel bowels. If you had a inline clear fuel filter, you could probably see this happening.

See if you get down on it on a long hill, if it happens even quicker. It should.

Apr 11, 2008 | 03:05 PM

#17

81-F-150-Explorer

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From: Northern California

Franklin's suggestion seems the most likely. IMO.

A bottle of "heet" wont hurt though.

Apr 11, 2008 | 03:54 PM

#18

JesterPgh

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Well, here's the findings from today. I hooked up my trailer today to go pick up this van for scrap. Also had about 1,500 lbs in the bed which I was unloading along the way. Had no problems, except when under heavier throttle usage, either going up hill, or pulling out from stops. If I was careful, and only used about 1/2 of the throttle, it wouldn't happen.

Apr 11, 2008 | 04:17 PM

#19

81-F-150-Explorer

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From: Northern California

8 psi pressure at the carb is good.

It really sounds like the bowl in the carb is running out of fuel, as Franklin suggests. How is your float adjustments?

Apr 11, 2008 | 04:25 PM

#20

uncle.stosh

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From: Out of here

Sounds like the accelerator pump is no good to me.

Apr 11, 2008 | 04:48 PM

#21

JesterPgh

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Just got done checking floats again, checked them wet, on the carb. Opened the sight plugs, and had them so fuel would *just* trickle out. Although, as I may feel like a ******* if I just fixed the problem, because it's going to be pure luck...I completely bypassed the mechanical pump, installed a new length of fuel line as the bypass, and am now only running the electric pump. It idled a bit nicer than before, and, whether it means anything or not, holding the pedal at mid level RPMs, it never stuttered. I'll have to road test it to be certain, but I almost think that the soft line to the original mechanical pump might have been sucking air. I'll post if the problem is solved after I drive it again tonight.

Apr 11, 2008 | 06:53 PM

#22

zeus77

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From: Globe, Arizona

Here's another thought....how much fuel pressure is the 1850 designed to run off of? I'm not familuar with holleys but my edelbrock AFB should run off of about 5.5 to 6 PSI max. At 6.5 PSI and higher of fuel pressure it floods and kills the engine. I had to put a regulator inline to fix it as my pump runs about 8psi.

Apr 11, 2008 | 08:08 PM

#23

ctubutis

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From: Denver Metro Area, CO

Quote:

Originally Posted by uncle.stosh

It might be a long shot, but what if his gas tank is
not venting?

Could be. To me, this is a classic flow problem and I had the exact same
symptoms - 3,000 RPM (60 or so MPH) and it'd begin coughing after a while. Let
up on the gas (or, alternatively, switch to the other tank) and it returned to
normal. But I knew exactly what was causing my problem because I caused it - a
tank-mounted fuel pump that wasn't hooked up and which also had an old sweat
sock on it as a filter (Redneck engineering, I know) and the mechanical pump
couldn't produce enough flow to keep the bowl filled up.

-ct