Without warning my wife's Grand Caravan (3.3 Engine) wouldn't start this morning. No trouble codes, no running rough.....just turns over and over without fire. I gave it some starting fluid and BAM, it fires right up and runs fine as long as the starting fluid is sprayed into the throttle body. So, at this point I know it's a fuel issue..... I check the 20 AMP fuse, it's fine...... I then swap out the Fuel Pump relay for the horn relay (Same relay) and still no starting, however the horn works so I know it wasn't the relay.

At this point I'm thinking it's the fuel pump...... so after siphoning out 3/4 tank of fuel I drop the tank and remove the fuel pump unit. I then take out the actual pump motor and start to head to the parts store, but then it dawns on me to test the pump motor. I do a quick test using a 12 volt battery and two jumper wires....and sure enough the pump takes off running like a new one. CRAP!!!

So, now I'm really scratching my head..... I put the entire fuel pump assembly back together and hook it back up to the minivan (minus the fuel tank) to see if I can get it to come on when I turn on the key or turn the engine over and of course it will not........

Now what??? Is it the PCM/ECM?????? If it is the computer why didn't it give me a trouble code? Is there something else that controls the on/off of the fuel pump between the fuse & relay???? I'm scared to death to go buy a new PCM and drop $300+ and it NOT be the problem! Anyway to test the PCM/ECM????

Any and all thoughts and comments are appreciated! Thanks.

 

Well, havent seen any PCM not turning on Fuel pump yet.
I doubt the PCM is completely dead because u said it ran with starting fluid.
Do you have a test light? test for power at the fuel pump connector. Or jump relay pin 87 with pin 30 with a wire, see if fuel pump/test light gets powered.

btw, are you working by urself? you realize when u cycle the key ON, the PCM will only power the fuel up for 2 second and shuts it off, right? So you have to look at the fuel "While cranking".

I think you need a fuel pump. Some times you wack the pump few times, it starts working again, so it is normal for it to start working after you drop the tank.

If no power coming off fuel pump connector while cranking, might want to check connectors under the fuse box for corosion.

The PCM controls the ground side of the relay, But the FCM gives it powers at pin 86 of the relay, while Pin 85 goes to PCM. Check pin 86 of the relay for power.
The Pin number I am talking about is stamped on the Relay itself.

 

Thanks for the reply...... No, I had a buddy with me as I was checking the pump to see if it would kick on briefly when I turned on the key.

I'll try checking for power as you described tomorrow and report the results. I'm HOPING it's not the PCM.... with the gas tank still sitting on the garage floor it would be way easier (and cheaper) to just slap a new pump into it and be good to go!

Much appreciated!

 

this might help

 

OK.... after a day and a half in 99 degrees, I got it figured out! When I pulled the actual pump motor, I disconnected a weird fitting that fit onto the motor leads and then the pos and neg wires attached to it. I hooked the motor itself up to the battery and it worked, and that's what had me puzzled.

So today I made sure I was getting power to the fuel pump, which I was. I talked to the guy at the parts place and he told me if I put in a "new" pump and it didn't fix my problem, he would take the pump back and give me my money back....so I had nothing to loose. When I put the new pump on it had that fitting I mentioned earlier already attached, so I hooked it up and it worked!!!! Come to find out, my original pump motor was fine, it was stupid connector that was bad somehow!!! I don't even know what the point of it is....I'd think the wires would attach direct to the pump motor but for whatever reason they plug into this fitting which sits on the top of the motor...... either way, it's working now!

Thanks for the assistance.

 

Good job!