Fuel Pump?

[David S]

Hello Guys and Gals!

I am a lurker and decided to join because I have a problem and wanted to seek out advice.. I have a 2000 GT with 140k miles on it that died while driving it home and it would not start. Was driving just fine and started to miss and stumble. Well flash ahead a few days and last night I had time to look at it. I checked to see if I could hear the fuel pump prime but couldn't.. Fuse is good and checked the inertia switch all fine. Sprayed some cleaner in the intake and tried to start it and it fired up until that burned off. I checked the schrader valve and some fuel came out but nothing else after that so I'm fairly certain either the fuel filter is blocked which I will change first and see if that fixes it but next is the fuel pump, correct? Any other diagnostics I can run?

Thanks in advance!

 

[wmburns]

Turn the key on/pause/off but do NOT crank. Listen for the fuel pump to run EACH time.

IF the fuel pump isn't heard, then test for key on +12 volt at the trunk mounted IFS switch.

• If no power at the IFS switch, then the problem is upstream such as fuse, CCRM, ignition switch, PCM.
• If there is power, the problem is down stream such as the FPDM, fuel pump itself, or wiring fault.

IF the fuel pump runs, then:

• bad fuel pump. Check to see what the fuel pressure is.
• bad fuel pressure sensor. The fuel pressure sensor is a no start sensor.
• clogged fuel filter or debris in the gas tank.
• "other" no start cause.

The fact that the motor starts on starter fluid indicates that everything is fine except for a lack of fuel.

 

[David S]

Thanks burns! How do I test the truck mounted ifs switch? I pulled the connector out and I only see 2 wires. I have a multimeter but admit I'm not the most knowledgable with it. I set it to volts? And tested the battery and got 12. Tried to hold the probes gently just touching the connector while the wife cycled the key on but no reading. Do we need to crank it or I feel my probes are not making contact. Thanks again for the help!

 

[wmburns]

When testing for voltage at the IFS switch set the Volt-Ohm meter to "volts". Put the black probe on a KNOWN good ground. Carefully back probe the IFS switch with the red probe. You may find it easier to use something long and thin such as a paper clip. The voltage should be present at the IFS switch anytime the key is in the on position.

Taking a voltage measurement "across" a closed switch is ALWAYS going to read zero. Pointless test.

 

[David S]

Thanks Burns! I'm desperate for some other help as I did the test at the ifs switch and there was power so I replaced the fuel pump. Still won't work.... Completely bummed. What else should I test or could it be? I used starter fluid again and it fires up and runs?

I checked the switch again and now no power at the ifs switch?

Uggghhhh

 

[David S]

Never mind!!!!!!! It runs!!! Will post later the why!

 

[David S]

So after being completely defeated I read your post again burns and went back to troubleshooting. I tested the ifs switch again and this time no power??? After trying and trying thinking I was doing something wrong because I tested that thing 8 times before and had power! I went back to the beginning and pulled the fuse out to check it again and what do you know the fuel pump fuse was blown this time. I swapped it out and it fired right up!!! I know I checked the fuse the first time too but maybe all my testing somehow blew it or something else? Who knows but it runs now! Thanks again for helping me diagnose it! Went from bummed to confident!!

 

[flstang65]

Keep a few laying around for the future!