fuel problems need help!

[zxdude]

ok heres my situation.... i just got my engine rebuilt and back together and we started it... and it fired rite up... but it ideled for like 5-10 seconds and turn off... we were unable to get it to start back up after this. so we found out it wasnt getting fuel.... when the ey was tyurned on the pump would not work.... but when the fuel pump test coinection was made it would work... the only thing that we could think of was that it must be the ECM..... any thoughts or ideas would be greatly appriciated....

Adam

 

[steve]

The capacitors leaking will cause problems powering up the fuel pump. Try grounding pin 7 on the MPI relay and see if the car runs that way. If so it's likely the ECU.

Let me know if you need it fixed.

Steve

 

[zxdude]

could you dumb that down for me im stil kinda a newbie.....

 

[steve]

The fuel pump is controlled by by a electronic switch on the right side of the center console under the radio called the MPI relay. Two things cause the switch to be turned on, the ignition switch being set to the START position and the ECU (Engine Control Unit, a small computer that runs the engine) Inside the ECU are small electrical storage devices called capacitors.
These fail over time for a bunch of reasons and leak an acid that eats away at the solder and copper that make up the connections inside the computer. Once the acid eats through the copper traces on the circuit board various parts of the computer fail like the circuit that controls the operation of the fuel pump.
One sign that this has happened is when the car will start and run for a few seconds after you release the key. By grounding the connector that the ECU grounds to switch the fuel pump on you can verify that is indeed the problem. If the car continues to run while your bypassing the ECU control of the fuel pump then the ECU needs repair.

Sorry, That's the best I can do.

Steve

 

[zxdude]

ok thanks for the info...

 

[99gst_racer]

The capacitors leaking will cause problems powering up the fuel pump. Try grounding pin 7 on the MPI relay and see if the car runs that way. If so it's likely the ECU.

Let me know if you need it fixed.

Steve

Steve, do you replace the caps in ECU's?? If so, how much? Please PM me.

Thanks -Paul-