I know nothing of that engine, but the chain is probably slack because it has been sitting a while without oil pressure and the tensioner relaxed. I wouldn't think this would prevent operation of the fuel pump, or if it does it would seem to be a significant oversight in the design.
Allan "Jerry Herrman" <jer...@san.rr.com> writes: > Anyone out there with experience as an engine mechanic involving an older > Ford 390 engine, specifically the fuel pump? > > This is on a '72 F250 I'm gonna get ready to sell. Last week when it would > not start, I disconnected the fuel line where it enters the carburetor and > found that the (mechanical) fuel pump was not delivering gasoline to the > carburetor. Knowing that the fuel pump has been in there since at least 1978 > when I bought it, and possibly since new in 1972, I was suspicious that it > had failed. I bought a new (Carter) at Pep Boys and removed the old one > (which involved disconnecting the power steering assembly and moving it > aside). I then installed the new fuel pump and was disappointed to find that > it did not move the fuel either. I then attached a fuel line to a container > of gas and turned over the engine with the starter. The new fuel pump would > not suck up the gas. > > I then removed the new pump and tested it by running the fuel line into the > container and moving the lever by hand. It sucked up the fuel readily. > > Then I hooked up the old pump to the fuel line and tested it by hand. Lo and > behold, it also sucked up the fuel just fine. This told me that my old pump > was still working. I reinstalled the old pump and hooked it up to the > container. It would not suck it up. > > > > So, to review, both new and old (40 years old!) fuel pumps work fine when > hand operated, and neither works when installed on the car. > > > > Enters now the possibility that I did not install the new pump correctly. > However, if that is the case, why was the old pump not working before I > removed it? > > > > By process of elimination, I am left with the unhappy prospect that the lever > on each pump is not being moved up and down by the cam lobe. So I tried to > peek inside that hole and noticed that there is what appears to be a chain > inside, and it appears to be kinda loose, and I can move it by poking it with > a screwdriver. When I crank the engine, the chain seems to move. I cannot see > straight inside, but by putting in a screwdriver, I can feel what may be an > eccentric cam, though I can't be sure. Looks like a huge job to remove the > cover plate over this area to see what is going on. Hence my appeal to > someone familiar with this area of this engine. > > Could that eccentric cam not be moving? If so, if I run the engine, will I do > more damage? > > By the way, last time I ran the engine, it was just fine. Can't understand > why, with the vehicle just sitting there, the cam would stop moving. > > > > I plan to bypass the mechanical fuel pump and install an electric pump, but I > worry that something is wrong inside the engine. What do you think? > > > > > > Jerry > > 82 240D > > 72 Ford F250 > > and others > > > > __________ Information from ESET Smart Security, version of virus signature > database 7054 (20120414) __________ > > The message was checked by ESET Smart Security. > > http://www.eset.com > > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -- 1983 300D 1979 300SD _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
