[Fuzzi_Butt]

well, I have posted about my Truck and it's starting problems. I bought a new fuel pump, but just as I was climbing under the truck to pull the old one, my neighbor come out and we got started talking.... Make a long story short, if my truck cranks if I fight it long enough, and stays running 10-45mins at a time, he is telling me that it COULD NOT be my fuel pump, cause if it was my truck would not get fuel at all and would not crank no matter how hard I fought it. Before I replace the pump, if this makes sense and it is not my lift pump, I will take the new one back and resume hunting for my problem . . . I am not that familiar with fuel pumps or how they work, but someone let me know if there is any truth to the old mans words before I go wasting money

 

[chuckster57]

Here's a quick fuel pump lesson:
mechanical pumps (like yours) use a diaphram to move fuel. Electrical pumps use a centifical vane to move fuel. The mechanical pump operates off a cam that moves the "arm" up and down. Electrical pumps use electrical power to run a motor that turns the vane.

As a general rule in my experiences the mechanical pumps will go bad and not move the proper volume of fuel. Electrical pumps as a rule either work or don't. You can do the flow test to see if your fuel pump is failing.

Do a pressure and flow test of the fuel pump at the Schrader valve on the filter header (FSS- fuel shutoff solenoid disconnected on IP). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when starter cranking engine over. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of starter engine cranking, route fuel to a suitable container with a hose. When all finished hook up the FSS wire .

When you say that it will run for 10-45 minutes, is that at idle the whole time?

 

[Fuzzi_Butt]

running for 10-45, mins, thats sitting idle or me reving here and there. I have heard alot about the flow test but cannot find the tool to remove the center of the tire valve, and do I do this with the truck running ?

 

[cdnsarguy]

Any steel tire cap with the split end will do it ....check your kids bicycle. Normally the test is done using the starter only........ your trying to see if there is sufficient pressure 4-6 psi and fuel quantitiy.

Fuel pumps are a cheap maintenance item....... they do NOT last for ever. Just ensure you install it correctly...... It's a biotch to do some times for the novice.....

This info pertains to Carter #M60278 pump or new long arm style.

WARNING

This fuel pump must be installed only at the low position of actuator cam.

If the pump is installed at any other position than low cam, the pump will be ruined, the engine will stall and damage may result.

Incorrect installation will loosen the pivot pin and allows the pin and lever to come out of the pump and drop into the oil pan. This can occur immediately or after several hundred miles. This type of failure is not covered by warranty.

To ensure that the cam is at low position, it is necessary to use a mirror and a remote starter switch. Observe the cam through the mounting port and bump the engine around until a one (1) inch wide machine surface is observed. This is low position of the cam. Now complete normal fuel pump installation.

9502CA
1991

 

[Otis B. Driftwood]

First of all you can't go wrong with the advice from cdnsarguy and chuckster57. But when I replaced my fuel pump I tipped the arm down when I installed it and slowly rotated it up until I felt it hit the cam and then bolted it in. It took a few tries just to make sure that it was in the right spot. Not saying that this is the best way or fool proof but it seems to work, but then again it was my truck and any mistakes will only cost me. Also when my lift pump started to go bad on my truck it would start hard and want to die unless it was revved up for a minute or so and it would surge while running down the road. Finally since pumps only cost about $30 and are not too hard to replace it is money and time well spent/