Strange 4bbl carb problem ... - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
ยป Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Fordforums Community > USENET NewsGroups > alt.trucks.ford
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto Escrow

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 07-29-2005, 18:01   #1 (permalink)
Steve
Guest
 
Posts: n/a
Strange 4bbl carb problem ...

On my 1985 351 E150 with a Ford/Holley 4 bbl carb:

For the last few days, I have smelled gasoline coming from the engine
compartment when the engine warmed up. I just presumed that a vent hose
had come loose so I wasn't worried about it. Then ...

I drove to town about 40 miles away, and the engine started running
TERRIBLY, like it was getting WAY too much gasoline. I immediately
headed straight home, but I used an entire tank of gas in just 40 miles!

Obviously a sunk float, or so I thought. I restarted the engine and
pulled the two float level screws from the float bowls, but no gas ran
out! Further, the engine now idles OK!

I suppose that a temporarily stuck float bowl valve could have done
this, but that wouldn't explain the smell, and besides, I don't like
"bogeyman explanations".

Any ideas what ELSE could have gone wrong to do this?

Thanks in advance for saving my carb.

Steve Richfie1d
  Reply With Quote
Sponsored Links
Advertisement
 
Old 07-29-2005, 20:01   #2 (permalink)
David M
Guest
 
Posts: n/a
Re: Strange 4bbl carb problem ...

On Fri, 29 Jul 2005 18:06:15 -0600, Steve rearranged some electrons to
form:

> On my 1985 351 E150 with a Ford/Holley 4 bbl carb:
>


> I suppose that a temporarily stuck float bowl valve could have done
> this, but that wouldn't explain the smell, and besides, I don't like
> "bogeyman explanations".
>


If the float was stuck and the valve was hung open, gas would have
been coming out of the vents & such. I would be surprised if
you DIDN'T smell gas.

--
David M (dmacchiarolo)
http://home.triad.rr.com/redsled
T/S 53
sled351 Linux 2.4.18-14 has been up 23:12 1 user

  Reply With Quote
Old 07-29-2005, 20:01   #3 (permalink)
Steve
Guest
 
Posts: n/a
Re: Strange 4bbl carb problem ...

David,

> If the float was stuck and the valve was hung open, gas would have
> been coming out of the vents & such. I would be surprised if
> you DIDN'T smell gas.


Oops, I forgot to mention that the air cleaner wasn't very dirty but it
WAS pretty much soaked in gasoline! I don't know where ELSE the gas
could have come from other than the vents.

However, it now idles OK, and with the air cleaner off I don't see any
gas coming from the vents, yet I STILL smell some gas. This doesn't seem
to fit ANY of the theories other than multiple problems. Hmmm, I guess
multiple problems IS a possibility in a 20 year old vehicle.

Decades ago I ran into a case where the fuel pressure went astronomical,
forcing its way into the bowls. This engine has a mechanical pump. I
wonder of its internal regulator could sometimes be going berserk?!

Thanks for your thought.

Steve Richfie1d
  Reply With Quote
Old 07-30-2005, 05:01   #4 (permalink)
David M
Guest
 
Posts: n/a
Re: Strange 4bbl carb problem ...

On Fri, 29 Jul 2005 20:31:28 -0600, Steve rearranged some electrons to
form:

> David,
>
>> If the float was stuck and the valve was hung open, gas would have
>> been coming out of the vents & such. I would be surprised if
>> you DIDN'T smell gas.

>
> Oops, I forgot to mention that the air cleaner wasn't very dirty but it
> WAS pretty much soaked in gasoline! I don't know where ELSE the gas
> could have come from other than the vents.
>
> However, it now idles OK, and with the air cleaner off I don't see any
> gas coming from the vents, yet I STILL smell some gas. This doesn't seem
> to fit ANY of the theories other than multiple problems. Hmmm, I guess
> multiple problems IS a possibility in a 20 year old vehicle.
>
> Decades ago I ran into a case where the fuel pressure went astronomical,
> forcing its way into the bowls. This engine has a mechanical pump. I
> wonder of its internal regulator could sometimes be going berserk?!
>
> Thanks for your thought.
>
> Steve Richfie1d


I can always smell a little gasoline when I run my Torino, but
that's probably because I have it jetted too rich :-)

--
David M (dmacchiarolo)
http://home.triad.rr.com/redsled
T/S 53
sled351 Linux 2.4.18-14 has been up 1 day 9:00

  Reply With Quote
Old 08-02-2005, 13:01   #5 (permalink)
Steve
Guest
 
Posts: n/a
Re: Strange 4bbl carb problem ...

Many thanks for everyone who volunteered their opinions, but after
tearing the carb apart and finding NOTHING wrong, it has been quite a
witch hunt to find the REAL culprit. Here is what apparently happened:

The fuel pump developed a microscopic leak in its diaphragm, which built
up fuel behind it (the business side is on the bottom, so the gas
collected on the top of the diaphragm). There was a 1/4" hole in the
side of the pump to keep any leaking fuel out of the oil, so it leaked
out there and THAT is what we smelled for days preceding the
semi-disaster. When I removed the fuel pump, it dumped a teaspoon full
of gasoline onto my hand from that vent hole. Further, everything below
the vent hole was VERY clean.

When, we drove ~50 miles to town on a HOT day, loaded up our trailer
with a half a ton of stuff, and generally heated the engine block well
above the boiling point of the gasoline. With the PCV system in good
working order, the vaporized gasoline from the leak was sucked IN to the
crankcase, some went into the oil (that gained about 3 quarts in volume)
and the remainder went either through the PCV or the crankcase vent to
the air cleaner. I suspect that in the process the leak got a lot worse.

Curiously, once in this mode, we didn't smell any more gasoline -
because it was no longer leaking externally, but was all being sucked
into the engine!

In total, this hassle ended up including:
1. Tearing apart a perfectly good carburetor.
2. Changing the oil and filter.
3. Replacing the air cleaner.
4. Replacing the fuel pump.
5. Replacing the tank full of gasoline that was lost, this being the
biggest actual expense of them all!

I had just gotten back from a long trip in this vehicle. I shudder to
think how this story would have turned out if this had all happened on
the road. By the time some repair shop had replaced the carb, etc., I
could have been out a LOT of money.

Thanks again for everyone's comments.

Steve Richfie1d
================
> On my 1985 351 E150 with a Ford/Holley 4 bbl carb:
>
> For the last few days, I have smelled gasoline coming from the engine
> compartment when the engine warmed up. I just presumed that a vent hose
> had come loose so I wasn't worried about it. Then ...
>
> I drove to town about 40 miles away, and the engine started running
> TERRIBLY, like it was getting WAY too much gasoline. I immediately
> headed straight home, but I used an entire tank of gas in just 40 miles!
>
> Obviously a sunk float, or so I thought. I restarted the engine and
> pulled the two float level screws from the float bowls, but no gas ran
> out! Further, the engine now idles OK!
>
> I suppose that a temporarily stuck float bowl valve could have done
> this, but that wouldn't explain the smell, and besides, I don't like
> "bogeyman explanations".
>
> Any ideas what ELSE could have gone wrong to do this?
>
> Thanks in advance for saving my carb.
>
> Steve Richfie1d

  Reply With Quote
Old 08-02-2005, 19:01   #6 (permalink)
David M
Guest
 
Posts: n/a
Re: Strange 4bbl carb problem ...

On Tue, 02 Aug 2005 13:09:19 -0600, Steve rearranged some electrons to
form:

> Thanks again for everyone's comments.


Glad to hear you got it fixed.

>


--
David M (dmacchiarolo)
http://home.triad.rr.com/redsled
T/S 53
sled351 Linux 2.4.18-14 has been up 4 days 22:26

  Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Fordforums Community > USENET NewsGroups > alt.trucks.ford



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are Off
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 11:24.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.