Low pressure pump popping breaker.

[Wish]

Replace low pressure pump breaker few months ago as it would pop periodically. Ran fine until today. Now new breaker popping at every start. Pump sounds weak. Does not have the high pitched prime sound. Does prime. But second boat turns over and runs for a few seconds, breaker pops, boat dies.

 

GT-40

1200hrs.

 

How can I test pump?. Or is it something else?. Ideas..Thoughts..

[JAG]

My '02 PCM 350 Chevy did this about a month ago. That system uses a low pressure pump to pull fuel out of the tank and deliver it to the fuel control cell, which then sends high pressure fuel to the throttle body. I found that inside the low pressure pump, there's a screen/filter that was plugged and blowing the 15a fuse repeatedly.

 

Not sure if you have a similar system or not, but thought I would share FWIW.

If you need more info, I can explain how to disassemble the low pressure pump.

 

PM me.

 

RPG

[Wish]

How do I check that.?

[Wish]

@rpg PMed you.

[The_MS]

Blame it on @OTF

[Chef23]

I think my next door neighbor had the same problem with his boat. I will talk to him and see how he fixed it. His boat is late 90s vintage 196 with I think the GT40 but I can't guarantee that.

[jhughes]

The low pressure fuel pump is one of the very few weak points of the otherwise fairly bulletproof GT40. At least every 10 years you have to figure it's going to go out. I had the exact same symptoms- it whirred up and made noise like it was fine but kept popping that breaker. Replacement is easy peace of mind and it's not that expensive of a part, particularly relative to this sport. 126.00 right now at Skidim.

[OTF]

@MS @wish tried. I promptly offered to charge him for all his MN sets, turns out it wasn't my fault :)

[Wish]

Bump. Any other thoughts? How can I isolate LP pump and test it for the prime sound I used to hear? Can Relay cause a weak sounding LP pump and pop breaker. Have no prob buying a new one but want to rule out any other possible causes.

[jhughes]

Even if it's not the pump, you need a spare. It's the pump though. Buy it and be done. It's not the relay, and besides it's one relay that drives both pumps. Switch the relays if you want, they are the same (ECU and Fuel Pumps).

[Wish]

This is the correct one for a 1997 GT40...Yes??

 

http://www.skidim.com/FUEL-PUMP-ELECTRIC/productinfo/RA080018/

[Orlando76]

Call Vince @ SkiDim in the morning to verify and so they can get it sent out on morning truck and you'll get it Friday. They are great about getting orders out quick.

[OTF]

@Wish your current connections were slide over vs clip together. Ask Vince about that too

[DefectiveDave]

I recently had this problem with the GT40 and fixed by replacing the low-pressure fuel pump. Might have been the same thing as mentioned by @rpg but I didn't bother disassembling the old one to find out.

 

It's apparently a common problem with your exact symptoms and is well documented on the correct craft forums. That is the correct part you've linked at skidim.

[Wish]

Part ordered. Any tips, tricks, suggestions for instal.? Hate working with fuel system. Always feel there is a true danger if done wrong. Any suggestions greatly appreciated. Plus they may help the next guy to come along with the same issue.

[DefectiveDave]

The main thing for me was that it was a pain to get something in there to catch the fuel due to clearance issues. A small cup ended up working pretty well for me. So long as you are just removing the LPFP, you only need to worry about the fuel in the pump and the intake line. There might be a little bit in the output line, but it should be minimal.

 

Also, take some wipes to clean fuel off your hands just in case (you can get them at the auto parts store). The chances of the gas igniting are very low (but not zero due to things like static discharge), but you don't want any on your hands or anything else in the off chance it happens.

 

Finally, you'll want something to deposit the caught fuel into (I used a gas can for old-fuel which I use with the lawnmower) and a rag to wipe up anything you miss. Good luck and be safe, fuel can be dangerous if you're not careful.

[OTF]

@Wish be a good idea to wait until off the dock to smoke your cigar

[Orlando76]

Hadn't done one yet on a PCM but assuming there's an o-ring gasket and this helped me alot on a Yamaha HPDI outboard I had:

Store o-ring in freezer for a bit rather in the sun. I've used Vasoline to hold gasket in place because they always seem 15% bigger than necessary. Somebody will probably come along say how bad this is but it's always been a success for me.

[Wish]

Done. Purrs like a kitten. Was nice to hear that bzzzzzzzt prime.

[Wish]

The only mod was the old pump has pin attachment points on the bottom for power and corresponding wire clips from motor..thinks spark plug and wire. New pumps do not have the pins. It comes with a 6" pig tail with a plug at end. Have to snip plug off and attach connecters to wires from it to boat. Shrink rapped them so good to go. Also painted the whole thing like the old one was for corrosion purposes.