In your manual check, were you pumping from the normal line from the tank, or some other source? Could you have a clogged filter somewhere upstream of the pump?
I had a 240Z with an electric fuel pump installed near the tank under recall (to solve possible vapor lock). The electric pump had an internal filter that got clogged by a load of dirty fuel. If it's not an upstream clog, it may be easier to add an electric pump vs tearing into the motor. -----Original Message----- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Jerry Herrman Sent: Saturday, April 14, 2012 6:08 PM To: mercedes@okiebenz.com Subject: [MBZ] Fuel Pump Not Delivering 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 _______________________________________ 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
