I have a 1993 f 150 that won’t start think it may be fuel pump after I hit it with starter fluid it starts but wont stay running any advise?
You need to follow the step by step procedure for diagnosing the problem. There are relays, fuses, crash switches and yards of wiring that might be causing the problem.
The quickest way to “start” diagnosing a fuel pump, electrical or mechanical, is to disconnect the discharge line and crank the engine.
Remove the gas cap and while listening down the fill tube, have someone turn the ignition switch to on.
You should hear the fuel pump run for a second or two and then shut off
If you don’t hear anything, rap on the bottom of the gas tank with a rubber mallet and listen again.
If you hear the pump run, the fuel pump requires replacement.
Tester
My fuel pump ('87 Toyota pickup) weakened gradually over the years. A new one cost $29; because it was mechanical it was easy to replace. Of course you should check everything else first, starting with the filter. You can take a mechanical pump off, work it by hand, see if fuel comes out.
Fuel pump for a 93 Ford F150.
https://www.rockauto.com/en/moreinfo.php?pk=1042772&cc=1122095&jsn=507
Tester
You know too much.
Yes you should hear the pump when you turn the key to the “on” position. The pump will activate and stop when it is up to proper pressure then you would turn key to “start” and it would run. Priming the engine manually and having it start then die indicates that 99% chance your pump has failed. One cause of failure is always running the vehicle with under a quarter tank of fuel. Fuel pumps are submerged which keeps them cool and it is no picnic pulling the tank down and out to service the pump! Low fuel also leaves too much air space in the tank which causes moisture condensation as well which contaminates the fuel and causes rust in a metal tank. Having the system checked by your trusted mechanic is a good idea if you can afford one!
That old style pump is easily tested with a vacuum gauge!
Should the fuel pump have any pressure you will then be pumping gasoline all over the engine and perhaps yourself as well. Not too smart. Do it outdoors and beware of any spark that would ignite fuel vapor which is what burns in the engine and anywhere else- the vapor.
The online parts place with the idiotic theme song for those who do not mind not having the part today and prefer to wait for delivery? Really? Plan on around 150 bucks at Auto Zone or the like, do not skimp on the quality and make sure the fuel lines do not get crimped when reinstalling the tank which is easy to do as they are flexible and impossible to see.
That image was was displayed for reference.
I never suggested that the part be purchased from Rockauto.
So what’s your problem?
Tester
I don’t have one. I disconnected it, took it off, attached the input hoses, worked the lever.
Could one pull off the hose coming from the fuel pump where it attaches to the injector, apply 12V to the pump, see if you get gas? With the engine off, of course.
It definitely sounds like a fuel pump problem. Before replace the pump, make sure it is getting proper power during cranking. A brand new pump won’t pump the gas either, if it isn’t getting proper power.
The easiest way to determine if the pump is the problem is to go to the Diagnostic Connector Link and look for a green/tan or blue/orange single wire lead located next to it.
That is the splice for the pump relay trigger circuit which grounds through the ECM. Run a jumper wire from ground to that single wire and listen for the pump. If you hear it running and the engine starts then the issue is likely a faulty ground in the ECM.
1 Like