Fuel Pump 101

[boscoman]

Correct me if I'm wrong, but didn't someone remove the pump from a fuel pump assembly a long time ago and find that it was a good fix? I had to replace the one in my 2005 Chevy Astro last year and it went without any warning, so I wasn't happy. I decided that I didn't want to spend $500 (at the lowest), so I bought a pump and changed it without dropping the tank by cutting a hole in the floor and installing an access door- I did all of the tests and the new pump has been working great. I decided not to test the old one immediately because I was already PO'd enough, but when I did, I saw that the two-wire harness had slid out of the Molex. I pushed it in and connected it to a battery- of course, it worked. Turns out that the male plug didn't have a barb on the retaining clip.

The pump I bought came from Autozone and comes with lifetime warranty- it cost about $100.

JimN, how the heck do I know which pump to buy though?

[boscoman]

Correct me if I'm wrong, but didn't someone remove the pump from a fuel pump assembly a long time ago and find that it was a good fix? I had to replace the one in my 2005 Chevy Astro last year and it went without any warning, so I wasn't happy. I decided that I didn't want to spend $500 (at the lowest), so I bought a pump and changed it without dropping the tank by cutting a hole in the floor and installing an access door- I did all of the tests and the new pump has been working great. I decided not to test the old one immediately because I was already PO'd enough, but when I did, I saw that the two-wire harness had slid out of the Molex. I pushed it in and connected it to a battery- of course, it worked. Turns out that the male plug didn't have a barb on the retaining clip.

The pump I bought came from Autozone and comes with lifetime warranty- it cost about $100.

JimN, how the heck do I know which one will fit my Millenium 3632-01

[JimN]

JimN, how the heck do I know which one will fit my Millenium 3632-01

Is the pump not working? If that's the case, I would remove it and look for a part number on the pump itself, then look online or at a local auto parts store. Unfortunately, there aren't any easy answers to this and since the Coast Guard has strict regulations for fuel delivery, the car and marine pumps aren't interchangeable.

[boscoman]

JimN, no, my pump is working fine, just want a backup so that if I do have a failure I can be on the water the next day. I'm probably not going to pull a working pump to check the numbers though.

[JimN]

JimN, no, my pump is working fine, just want a backup so that if I do have a failure I can be on the water the next day. I'm probably not going to pull a working pump to check the numbers though.

I'm sure you have heard and read it, but the best way to not need to replace a pump is to never run it dry or go below 1/4 tank. If the boat is driven in a way that causes the gas to slosh, I wouldn't go below 1/2 tank.

[boscoman]

I'm sure you have heard and read it, but the best way to not need to replace a pump is to never run it dry or go below 1/4 tank. If the boat is driven in a way that causes the gas to slosh, I wouldn't go below 1/2 tank.

yep, I'm trying to treat my pump well....somewhat of a side issue is after a day on the lake and the fuel gauge says 1/4, go get gas and it only takes 1/2 tank....which I guess really is a safety factor for the fuel pump, better than if the gauge read high all the time and tank was actually low, but it would be nice if the gauge was accurate. The only time you can see for sure that the boat position is affecting things is hole shot for skiing. When the bow looks heavenward, the gauge goes to full

[JimN]

yep, I'm trying to treat my pump well....somewhat of a side issue is after a day on the lake and the fuel gauge says 1/4, go get gas and it only takes 1/2 tank....which I guess really is a safety factor for the fuel pump, better than if the gauge read high all the time and tank was actually low, but it would be nice if the gauge was accurate. The only time you can see for sure that the boat position is affecting things is hole shot for skiing. When the bow looks heavenward, the gauge goes to full

Unfortunately, it would be almost impossible to make a tank that has enough baffles to prevent sloshing AND seal tight/not be two pieces that need to be attached and therefore, more likely to leak- that kind of plastic isn't the easiest to bond together, AFAIK. The other part of this is: It needs to be approved by the USCG.

[Bouyhead]

I'm helping out a friend with a 07' X7 w/ the RTP motor. The boat has an intermittent no start condition. Most times it starts and runs fine but occasionally it will just crank and not start. I'll get started today with the usual diagnostic work checking fuel pressure, connections, relays, etc. I do have one question, Did anybody have an intermittent no start condition that was rectified by replacing the fuel pump? TIA

[Bouyhead]

I'm helping out a friend with a 07' X7 w/ the RTP motor. The boat has an intermittent no start condition. Most times it starts and runs fine but occasionally it will just crank and not start. I'll get started today with the usual diagnostic work checking fuel pressure, connections, relays, etc. I do have one question, Did anybody have an intermittent no start condition that was rectified by replacing the fuel pump? TIA

Update: Fuel pressure is 58 psi w/ key on engine off and also 58 psi while idling. Used my Rinda scan tool to test the fuel pump and relay. Relay clicks and pump primes every time. Kill switch is disconnected. The only thing I found was when the motor was idling for a few minutes the wires going to the fuel module get very hot to the touch. I disconnected, inspected and cleaned all the grounds but the wires on the module still got hot. Any ideas?

[mtajpa]

Pump is probably on its way out drawing more current than usual. Will eventually start melting plastic connectors. Also depending at what point the armature stops it may not start pumping again. This happened to me. Install an airtex pump an no problems since.

[Bouyhead]

Thanks Mike! Glad to see you're still around. Remember that 205V project boat I had years ago that was a no start? Lots of guys had some good info but you were the kingpin!

[mtajpa]

Hi Mike yes still around. Here is a picture of the pump issue I had. You can see the brush is melted into the plastic holder not allowing it to spring out an apply any pressure to the armature.
Caused several momentary starts and stops. The wires were getting hot as well new no more heating up.

[JimN]

Make sure the terminals in the plug that's connected to the pump are clean and snug. If the pump has been replaced, the new one should have come with a pigtail because excessive heat in the terminals causes them to lose their grip.

I have seen an aftermarket repair kit for this that has one gauge of wires, none of them heavy enough for the battery connection. Don't use that one (Dorman) and definitely use Heat N Seal but splices when making any connections.

[mtajpa]

Here is a replacement harness rated at 20amps




https://www.racetronix.biz/p/univers...QaAhwREALw_wcB

[Bouyhead]

Update: After removing the pump and getting it all apart my friend decided to go a different route and buy the whole new assembly. He's not the original owner and it appears someone has been thru that pump assembly before. Some of the hold down bolts were stripped, a chunk of plastic was missing from the module, and one of the electrical connections to the pump was boogered.

Most dealers have the pump assemblies on back order and the ones that are coming in are all spoken for. He did find one in TN, it should be here Wed-Thur.