I was driving the truck today and all a sudden it just died! It turns over and will run for like 2 seconds and then just die. There is clicking coming from inside the tank and from the fuse box under the hood when the key is turned all they way forward.Last week i practically ran it out of gas. Ever since then the check engine came on and its been idling high, like at 1300rpms when its worm. Could this be the fuel pump, i checked all fuses and they seem ok. O and also when the key is turned all the way forward it sounds like there is a humming electrical sound comming from the pcm. Its the 1995 318

 

any one have an ideas?

 

well the electric HUUMMMMMMM from the PCM is not good lol.....Maybe when you ran out of gas you pumped stuff from the bottom of the tank.....any codes???

 

yea the check engine is on, but i havent read the codes yet. The check engine light came on when i ran it out of gas. When i got it fired after i ran out of gas, the idle has been high also.

 

Well you gonna need to run a few tests....

Pull the codes out of the pcm. Maybe a sensor blew or something.
Check the fuel pressure with a gauge.

It sure sounds like an electrical problem tho.....

 

Since the FUEL PUMP must be loaded down at all times (to prevent burning the motor out), what most likely happened is, the motor windings overheated thus, melting the insulation thus, leading to a partial short condition thus, the sound of buzzing or resonating relays on that CKT.

In the PCM, there's a ground return for the FUEL PUMP AND ASD RELAY and, if there's a short on the CKT, the PCM usually senses high current draw and OPENS this ground path thus, SHUTTING DOWN POWER to not only the FUEL PUMP but, the entire EFI system as well.

Here's a quick and dirty test:

Lay under the vehicle with your head near the tank. Have someone turn the KEY <ON> but, DO NOT ATTEMPT TO START IT.

You should hear a whirring sound or, some audible sound alerting you that the FUEL PUMP motor is active and spinning in the tank for 2-3 seconds MAX.

If you hear nothing but humming or clicking- The motor has LOCKED UP due to overheating or, SHORTED WINDINGS thus, the HUM. IF it whirs and sounds like it's spinning, you will hear a higher pitched frequency / tone vs. a lower pitched HUMMING.

Check it and get back to me.

CM

 

If you have a CEL, why would post a question that would make this all guess work? Have the code's read or try the key trick! (95 you count the flashes) Geez!

 

ok so when i laid under the truck with the key turned on but not trying to start it, all the pump does is click, but!!! Theres a clicking coming from the fuse box under the hood, and the manual shift light(it tells you when to shift) is flashing.

 

There is a relay up in the PDC labeled, FUEL PUMP RELAY. You will want to test that before condemning the pump. There's a test for that to verify if it's working or not or, you can simply measure for voltage at the pump to verify whether or not there is voltage or not.

However, if and when there's a short at the windings in the motor, this draws excessive current thus, heating up all the components in that CKT thus, the relay may have been thermally damaged thus, the clicking. This is why you really should test it in order to rule that out and, if you look into the Haynes or Chilton manuals or on-line, you will find a test procedure. If that checks out fine and passes test- you know with almost 100% certainty that the root cause is a failed FUEL PUMP MOTOR due to having no load on it.

But, in order to find this out fast, one must start test things.

CM

 

Jumper the fuel pump relay and see what happens. When you remove it, you'll see four or five terminals. They are labeled on the bottom of the relay and 85, 86, 87 and 30 (if it is a five terminal, there'll be an 87a). You want to jump the PDC from where terminal 87 and terminal 30 are when the relay is plugged in. Verify battery voltage at terminal 30.

If the fuel pump still doesn't run, you either have a problem with wiring between the PDC and pump, a pump ground issue, or a bad pump.