New fuel pump issue

[dgf65]

Hard starting issue 87 2.9

HI dgf65 here
I'm having issue's with my fuel pump. I replaced the fuel pump last Saturday because I had no fuel pressure & It would barly start the truck.But as soon as I put the new pump in, It started & ran fine.

Now I am having the same problem Its been 4 days & It will not start.You can here the pump run when you try to start It. One thing I thought was funny when the truck was running I could here the pump run most of the time.
Any idea what could cause the pump to go bad.
Thanks
dgf65 Dale

 

[dernst]

How do you know the the pump was bad in the first place? A few things could be the cause:

A bad relay for the fuel pump.
A bad fuel pressure regulator.
A bad inertia switch--this is located in front of the passenger floorboard.
A bad electrical connection.
A bad in tank fuel pump.
A clogged fuel filter--there may also be a filter in the reservoir before the pump.

There could also be problems with your ignition module not telling the computer that the motor is spinning and needs fuel.

You need to check a few more things before you just start buying parts.

 

[IMenriched]

What vintage do you have?? 86'-89? i believe had 2 fuel pumps...1 in tank and 1 in line or on the frame.

which one did you replace?

and yes it could be as ^derst^ mentioned

 

[dernst]

dgf65's private message to me...

I used a fuel pressure gauge from a garage & I got zero read out & they told me to change the pump & that worked & now it just stopped working all of a sudden.

I rebuild the truck about a year ago most everything is new filter,FPR,Map, secondary pump,It is a super cab.I did notice the plug on the tank pump was breaking down when I had it out.

What is the best way to check the relays & the other switches.Also can you buy that plug at the part store that goes on the tank.

Remember I said on my post that It sound like the pump was running all the time I don't remember hearing that when the truck was running fine.
Thanks
Dale
Instead of sending me a privite message, you should state all of the information in a post so that others can see it and help as well. It does help others when they have more information like you stated in your PM.

If I suspect a bad relay, I will usually replace it with a know good one. I usually have a few extra ones around my shop. On some vehicles, you have extra non essential relays that can be removed and placed in the desired location. On your truck, I believe that the only other one is for the ECC.

As far as checking relays, I will pull the top cover off and check to see the the contact points or anything else looks fried. I'll will also visually watch them as they are pluged in to make sure they are working. You could also use a DVOMM and do contunity and power checks.

Remember, the fuel pump will only run for a few seconds right when you turn the key on. This is to pressurize the system. It will not turn on again until the motor starts to spin.

 

[dgf65]

Hard start

I pulled the plugs looks like excessive carbon & wet from gas dose this sound like a leak down in the injector.
I key on it pumps up to 15 lbs key twice 40 lbs it takes about 20 minutes to go back to zero.

It acts like its fluided when I try to start it I crank & crank & when it finaly starts it stumbles & takes about 25 seconds to run a little better.
dgf65

 

[dgf65]

Hard start

I went to the yard yesterday & picked up a different front pump & a coolant temp sensor.
This is just to see if I can get it to hold pressure.

There was another sensor on the back of the block on left side that reads gas,coolant,air or something like that not the FPR.