swap help but might be a newbie mistake lol..please help

[1baggedranger]

hello i recently installed a 91 mustang 2.3 into my 91 ranger 5 speed. but it will crank but but not getting fuel to the injectors. and the fuel pump wont kick on only if i use a jumper. i jumped the starter relay and use starting fluid so i know I'm getting spark but if i try to start it up normally with the ignition. it just cranks but wont start....

ps i think I'm might know the answer but just wondering i didn't swap the computer could that be the problem ?any info would be so helpful thanks in advance..

 

[Earl43P]

In this diagram, you can see the ignition switch powers the ignition system AND the EEC (PCM) relay (so I think your ignition switch is good). http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Ignitionsystem_1990_2_3.JPG

Then, in this diagram, http://www.therangerstation.com/tec...les/Diagram_ElectronicEngControls2_3_1of3.JPG you can see where if your PCM relay doesn't work, the fuel pump relay will never get powered. So look into those two relays' problem.

The last thing is that the PCM applies the GROUND for the fuel pump relay. It should do that "prime" of the fuel pump for 2 seconds each time you turn the key from Off to Run. Listen for that. When it's cranking and running, the PCM applies the ground to the fuel pump relay based on seeing the Crank sensor signal. We suspect that is OK because you said you have spark.

Make sure you have a good ground connection for the PCM (should be one wire to ground right there) and again for the Bat- to radiator support.

The PCM power diode in the fusebox should also be checked.

 

[1baggedranger]

In this diagram, you can see the ignition switch powers the ignition system AND the EEC (PCM) relay (so I think your ignition switch is good). http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Ignitionsystem_1990_2_3.JPG

Then, in this diagram, http://www.therangerstation.com/tec...les/Diagram_ElectronicEngControls2_3_1of3.JPG you can see where if your PCM relay doesn't work, the fuel pump relay will never get powered. So look into those two relays' problem.

The last thing is that the PCM applies the GROUND for the fuel pump relay. It should do that "prime" of the fuel pump for 2 seconds each time you turn the key from Off to Run. Listen for that. When it's cranking and running, the PCM applies the ground to the fuel pump relay based on seeing the Crank sensor signal. We suspect that is OK because you said you have spark.

Make sure you have a good ground connection for the PCM (should be one wire to ground right there) and again for the Bat- to radiator support.

The PCM power diode in the fusebox should also be checked.

thanks i will try that .. and the pcm diode is in the fusebox under the driver side steering column