GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Re: [GMCnet] Anyone have a loose fuel pump?
Re: [GMCnet] Anyone have a loose fuel pump? [message #332401] Tue, 22 May 2018 10:17
sgltrac is currently offline  sgltrac   United States
Messages: 2797
Registered: April 2011
Karma:
Senior Member
Another nugget of learning thanks to the GMC net.

Sully
77 eleganza 2
Bellevue.

On Tue, May 22, 2018 at 8:15 AM James Hupy wrote:

> Darn spell check. Should be cam lobe, not lube.
> Jim Hupy
>
> On Tue, May 22, 2018, 8:12 AM James Hupy wrote:
>
>> There are usually 2 springs in modern mechanical fuel pumps. One whose
>> purpose is to keep the operating lever in contact with the cam lube, is
>> quite strong. The other spring, which actually presses against the
>> diaphragm, is the one that actually pumps the fuel. It has about 3 - 5
>> pounds pressure. It is compressed by the movement of the operating lever,
>> and relaxes against the diaphragm. If there is an equal pressure against
>> the other side of the diaphram, like there would be when the carb needle
>> were closed, then that small spring does not move the diaphram and no
>> pumping takes place until the float needle opens. So, now you know how
> the
>> mechanical pump regulates fuel pressure.
>> Jim Hupy
>> Salem, Or
>> 78 GMC ROYALE 403
>>
>> On Tue, May 22, 2018, 7:55 AM John R. Lebetski
>> wrote:
>>
>>> Maybe they increased the spring load to keep them from sticking or to
>>> keep contact for the "racer" market?
>>> --
>>> John Lebetski
>>> Woodstock, IL
>>> 77 Eleganza II
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Sully 77 Royale basket case. Future motorhome land speed record holder(bucket list) Seattle, Wa.
 
Read Message
Previous Topic: Tracker soft top parts
Next Topic: Found loose axle nut - what should I do next?
Goto Forum:
  


Current Time: Sat Nov 16 23:50:48 CST 2024

Total time taken to generate the page: 0.00694 seconds