2001 GTX DI - Fuel Pump

[Grast5150]

Morning Everyone,

I wanted to share my recent experience with my Sea-doo 2001 GTX DI. My youngest drove the ski off the lake telling me it was surging and had no power. As we all know, DI can be a little finicky and they required 107 PSI Fuel Pressure, 80 PSI of Air, and Good Spark. After I took the ski out and noticed the following symptoms.

- No Power
- RPMs no higher than 3500
- Extreme Surging from 2500 to 3500 RPM
- WOT caused engine to die

So, the day was done and took home to diagnose. Once I started the ski, It performed as expected with normal idle and was able to get up to the 6000 RPM range. So......inconsistent Wonderful. My initial thought was something wrong with the Air side as the fuel pump was basically new with less than 40 hours on it. I was also noticing a gurgling noise on the fuel rail. So, I started diagnosing. I first verified the air rail had 80 PSI at start and through throttle range. Air Checked good. The next step was testing Fuel Pressure. The manual states that with key inserted, fuel pump should run and show 27 PSI. I noticed that while pump was running it was at 27 PSI but after 2 seconds it turned off. The fuel pressure immediately started to drop and could hear the gurgle sound. If the rail does not hold pressure before engine start, That is a faulty Fuel Pressure Regulator. I replaced the regulator and resolved the pressure drop. I thought the issue should be solved and took out on the lake. Short story....NO!

Back to testing and more fuel pressure testing. Fuel pressure should be 27 PSI at key insert and 107 PSI +- 2PSI when running. When I tested the ski, All of these numbers were correct, So cant be the fuel pump. On a hunch, I put water on the ski and kept it running. This is when I noticed the true issue. The fuel pump would start off at 107 PSI but after 5 minutes pressure had dropped to 100 PSI and after 10 Minutes dropped to 92 PSI and the engine stalled. So, the fuel pump was the issue. So I pulled it out in order to inspect.

See attached picture. This is a Quantum Fuel System Fuel pump. As you can see it is bent at the fitting which was causing a loss of pressure during operation. My only thought is that movement of the ski with the pressure of the spring caused the fitting to fail. I have to say that Quantum is honoring their lifetime warranty. My goal of this post is that physical inspection of the fuel pump should be done if you have any issues which appear to be fuel related.

Thanks.

 

[WaarrEagle]

Thanks for posting. It is rare to see people follow the tried and true troubleshooting steps with a DI. But you did and found your issue.

 

[etemplet]

What model pump is that. I have read of successes replacing with aftermarket but only with one specific model.

On a side note, I think the DI is the most BAD azz 2-stroke in the barn.

 

[Grast5150]

What model pump is that. I have read of successes replacing with aftermarket but only with one specific model.

On a side note, I think the DI is the most BAD azz 2-stroke in the barn.

The unit in the picture is Quantum HFP-342DI. However, it is no longer sold. I have another DI which uses the better Quantum HFP-501DI. It is unibody design very similar to stock which does not have the fitting of 342DI. I would recommend the HFP-501DI as it is as direct as replacement to stock fuel pump on the market. No more splicing of wires and it feels very sturdy.

Thanks.

 

[Grast5150]

Thanks for posting. It is rare to see people follow the tried and true troubleshooting steps with a DI. But you did and found your issue.

Thank-you, I know that DIs have a bad rap but in my opinion they are the best of any 2-stroker. You just push button and they start whether cold or hot, they do not stink like most 2-strokes, and have lots of power. But I will admit they are the most expensive 2-stroke anyone will operate. The 2-Stroke Full Synthetic Oil is about 75 dollars a gallon and use of cheaper oils will result in one thing....damage to the engine and reduced life. Most consider the biggest limitation is the wear of the engine which is about 250-275 hours. Here is the rub though, If you use OEM 2-Stroke Full Synthetic Oil, The crankshaft will last and the top end will only need a 25 thousand bore out. A typical head can take upto 8 25 thousands bore out before sleeving. So lots of life

I look at it this way. Most people put 50-60 hours per year on their ski. That is 5 years of good use before needing to rebuild the engine.

All 3 of my DIs had one common issue, OIL STARVATION. My 1st DI, the oil lines melted on the exhaust because manufacture made them too long. It destroyed the Mag cylinder and had to sleeve it. 2nd DI had a good life of 260 hours, but the last owner used cheap 2 stroke oil in the last 50 hours which congealed in the oil tank and caused the PTO cylinder to loss half of it life. 3rd and final only has 100 hours and once again used cheap oil. It cause prematured failure of the counter balancer shaft which failed and broke the case.

So moral of story is dont use cheap oil.

If you use the right oil and dont sink your ski, the crankshaft should last 500 hours before needing a rebuild and the top end is good for 250 or so hours. If you can do they work yourself, I think DIs can be good projects. If not so handy, I would suggest one of the older 4 strokes.... They have come down in price these days.

Later.

 

[etemplet]

If people world ride these ski even 30 hours a year they would have less problems. Most people just let them sit and they are lucky if they get on the water monthly. Glad to hear a definitive report on the DI engines. So much mis and dis- information out there.

 

[mikidymac]

@Grast5150. This is great news for the DI fuel pumps. I hope the lasting solution is the HFP-501DI. I am so tired of telling DI owners the only solution is a crap shoot, used OEM pump.

And I would be lucky to get 5-6 hours per year on each ski, let alone 50-60.....

 

[Wess]

I had the same problems, when I removed the pump from the tank, I found a lot of debris on the filter. Replaced the filter and my problem was solved.

 

[Mark93]

hi, I’ve got almost the same symptoms you have with anything over 5000 RPM and it chokes out coughs and splutters. I have used a pressure gauge when its on the trailer and have 107 psi… up until 6000 ish and then it get big fluctuations on the pressure… I pulled the fuel pump and it’s bent just like yours. I have enquired about the hfp-501di with QFS about the difference between the original (hfp-342di), the hfp-501di only produced 98 psi but the original, 342di outputs 107?

Which seems strange if it’s working on your machine?

Morning Everyone,

I wanted to share my recent experience with my Sea-doo 2001 GTX DI. My youngest drove the ski off the lake telling me it was surging and had no power. As we all know, DI can be a little finicky and they required 107 PSI Fuel Pressure, 80 PSI of Air, and Good Spark. After I took the ski out and noticed the following symptoms.

- No Power
- RPMs no higher than 3500
- Extreme Surging from 2500 to 3500 RPM
- WOT caused engine to die

So, the day was done and took home to diagnose. Once I started the ski, It performed as expected with normal idle and was able to get up to the 6000 RPM range. So......inconsistent Wonderful. My initial thought was something wrong with the Air side as the fuel pump was basically new with less than 40 hours on it. I was also noticing a gurgling noise on the fuel rail. So, I started diagnosing. I first verified the air rail had 80 PSI at start and through throttle range. Air Checked good. The next step was testing Fuel Pressure. The manual states that with key inserted, fuel pump should run and show 27 PSI. I noticed that while pump was running it was at 27 PSI but after 2 seconds it turned off. The fuel pressure immediately started to drop and could hear the gurgle sound. If the rail does not hold pressure before engine start, That is a faulty Fuel Pressure Regulator. I replaced the regulator and resolved the pressure drop. I thought the issue should be solved and took out on the lake. Short story....NO!

Back to testing and more fuel pressure testing. Fuel pressure should be 27 PSI at key insert and 107 PSI +- 2PSI when running. When I tested the ski, All of these numbers were correct, So cant be the fuel pump. On a hunch, I put water on the ski and kept it running. This is when I noticed the true issue. The fuel pump would start off at 107 PSI but after 5 minutes pressure had dropped to 100 PSI and after 10 Minutes dropped to 92 PSI and the engine stalled. So, the fuel pump was the issue. So I pulled it out in order to inspect.

See attached picture. This is a Quantum Fuel System Fuel pump. As you can see it is bent at the fitting which was causing a loss of pressure during operation. My only thought is that movement of the ski with the pressure of the spring caused the fitting to fail. I have to say that Quantum is honoring their lifetime warranty. My goal of this post is that physical inspection of the fuel pump should be done if you have any issues which appear to be fuel related.

Thanks.

 

[clt1meb]

I am having a little struggle with my 2002 DI. There is a little break in the rubber gasket end of this piece attached to the fuel pump. I am wondering if I could be losing pressure there. I cannot find a part number for this specific piece. Any ideas?

 

[WaarrEagle]

I am having a little struggle with my 2002 DI. There is a little break in the rubber gasket end of this piece attached to the fuel pump. I am wondering if I could be losing pressure there. I cannot find a part number for this specific piece. Any ideas?

The image you posted is from an aftermarket Quantum pump. It has a different design from OEM. If you have the same pump, you need to contact Quantum for parts.

 

[DooWacka]

He is talking about the OEM aluminum fitting and it's black rubber seal.
There is no seperate part number for that seal, unfortunately.
In the "old" days I would ask and receive the discarded pumps when the dealership replaced them, so I could scavenge that aluminum part with it's all-important seal.
I have never found a way to get that seal any other way.
In the past the dealership would have to replace the entire fuel module if the seal was bad.
It is a double-lipped seal that I have never seen elsewhere.
HPF or Quantum will not have this part, but it couldn't hurt to ask them, they have surprised me in the past.

 

[clt1meb]

He is talking about the OEM aluminum fitting and it's black rubber seal.
There is no seperate part number for that seal, unfortunately.
In the "old" days I would ask and receive the discarded pumps when the dealership replaced them, so I could scavenge that aluminum part with it's all-important seal.
I have never found a way to get that seal any other way.
In the past the dealership would have to replace the entire fuel module if the seal was bad.
It is a double-lipped seal that I have never seen elsewhere.
HPF or Quantum will not have this part, but it couldn't hurt to ask them, they have surprised me in the past.

That is what I am hearing. I bought the fuel pump from Quantum. They were very helpful but did not have that part. I will have to check around with some local refurb shops. The dealers are not even working on 2002 models around here.

 

[Mark93]

He is talking about the OEM aluminum fitting and it's black rubber seal.
There is no seperate part number for that seal, unfortunately.
In the "old" days I would ask and receive the discarded pumps when the dealership replaced them, so I could scavenge that aluminum part with it's all-important seal.
I have never found a way to get that seal any other way.
In the past the dealership would have to replace the entire fuel module if the seal was bad.
It is a double-lipped seal that I have never seen elsewhere.
HPF or Quantum will not have this part, but it couldn't hurt to ask them, they have surprised me in the past.

I believe this new pump they’ve not long brought out (HFP-501DI) has the aluminium part with the seal.

 

[Mark93]

But the only issue with the pump is quantum state it only supplies 95 psi which isn’t enough… however on the EBay advert it states it’s suitable for the DI engines

 

[clt1meb]

I believe this new pump they’ve not long brought out (HFP-501DI) has the aluminium part with the seal.

Good to know. Thanks for the info and the picture. I think I will give it a try. When I 1st replaced the fuel pump, it ran great. Held 107 +/- psi, all good. but after about 15 minutes it went back to only about 70-80 psi and constantly cut out. Restarted right away, but soon dies. The best price I can find for a new OEM whole fuel housing was about $800. And that is painful to buy if I am not certain it will fix the ski.

 

[DooWacka]

I believe this new pump they’ve not long brought out (HFP-501DI) has the aluminium part with the seal.

Yes, you are right, that looks just like the seal. Good.

When I 1st replaced the fuel pump, it ran great. Held 107 +/- psi, all good. but after about 15 minutes it went back to only about 70-80 psi and constantly cut out. Restarted right away, but soon dies.

Yes, I have seen the same. These pumps were not made for the higher pressure but some can work at 107 psi for quite awhile. I hope that HFP/Qauntum has asked their manufacturer make them work continuously at 107. The HFP-342 has the pressure relief port on the top, so I have had longer service by using epoxy to plug that port. However, the HFP-500 apparently had the port internally so I could not plug it, hence it failed for me. I hope they have asked their manufacturer to fix that in the HFP-501.
I currently have HFP-342 in all four of my DI.

 

[Mark93]

Yes, you are right, that looks just like the seal. Good.

Yes, I have seen the same. These pumps were not made for the higher pressure but some can work at 107 psi for quite awhile. I hope that HFP/Qauntum has asked their manufacturer make them work continuously at 107. The HFP-342 has the pressure relief port on the top, so I have had longer service by using epoxy to plug that port. However, the HFP-500 apparently had the port internally so I could not plug it, hence it failed for me. I hope they have asked their manufacturer to fix that in the HFP-501.
I currently have HFP-342 in all four of my DI.

That’s really interesting, I’m going to try and get hold of the 501 but where is the relief port? I might try and JB weld it?

 

[DooWacka]

I know the 500 doesn't have a visible relief port because I have worked with two. I would assume the same for the 501. Unfortuneately, the 501 designation may only mean that all the other items like the seal are included. Hopefully Quantum folks asked their manufacturer to increase the relief pressure of the 501, and it is then a better pump for us.

 

[Mark93]

I know the 500 doesn't have a visible relief port because I have worked with two. I would assume the same for the 501. Unfortuneately, the 501 designation may only mean that all the other items like the seal are included. Hopefully Quantum folks asked their manufacturer to increase the relief pressure of the 501, and it is then a better pump for us.

I was told by quantum that the 500 is rated to around 50psi but not sure on the exact number and the 501 is higher.. I’ve got a 501 on order so will let you know

 

[Mark93]

I know the 500 doesn't have a visible relief port because I have worked with two. I would assume the same for the 501. Unfortuneately, the 501 designation may only mean that all the other items like the seal are included. Hopefully Quantum folks asked their manufacturer to increase the relief pressure of the 501, and it is then a better pump for us.

Out of curiosity, which part of the 342 did you epoxy ?

 

[Mark93]

I was told by quantum that the 500 is rated to around 50psi but not sure on the exact number and the 501 is higher.. I’ve got a 501 on order so will let you know

Is it this who pictured?

 

[Mark93]

I know the 500 doesn't have a visible relief port because I have worked with two. I would assume the same for the 501. Unfortuneately, the 501 designation may only mean that all the other items like the seal are included. Hopefully Quantum folks asked their manufacturer to increase the relief pressure of the 501, and it is then a better pump for us.

apologies for bombarding you hahah but my head is going 100 mph trying to figure this out but on the bottom of the pump I have a black rubber section that connects to a filter. However it appears to be blocking the suction of the pump which seems really strange? Is there supposed to be a hole where I have arrowed on the pictures below? It could explain my flow issues at higher demands?

 

[DooWacka]

Yes, the black rubber piece you are showing should be a straight through hole. Did that shown piece come from Quantum? The OEM has a big see through hole. That would be bad if the Quantum part is not see through. The smaller of the two filters is the one you are showing and it only re-filters fuel that is coming from inside the fuel module. The larger filter screen/sock is on the bottom of the module and filters fuel coming in from the tank. The module foot valve allows the module to be very full even when the tank is near empty, since all the fuel returning from the rail gets dumped in the top of the module.

Regarding your other question:
The pressure relief port in the 342 pump is in the blue plastic top right next to the outlet fitting.

Also, if Quantum says the 501 is only good to 95 psi, they need to tell their supplier/manufacturer to increase that to at least 110 or 120 psi.

I don't know if the OEM Seadoo pump (from Airtex) had a relief valve. I have bench tested the OEM pump to over 160 psi and it was still climbing strong but I chickened out.

 

[Mark93]

Yes, the black rubber piece you are showing should be a straight through hole. Did that shown piece come from Quantum? The OEM has a big see through hole. That would be bad if the Quantum part is not see through. The smaller of the two filters is the one you are showing and it only re-filters fuel that is coming from inside the fuel module. The larger filter screen/sock is on the bottom of the module and filters fuel coming in from the tank. The module foot valve allows the module to be very full even when the tank is near empty, since all the fuel returning from the rail gets dumped in the top of the module.

Regarding your other question:
The pressure relief port in the 342 pump is in the blue plastic top right next to the outlet fitting.

Also, if Quantum says the 501 is only good to 95 psi, they need to tell their supplier/manufacturer to increase that to at least 110 or 120 psi.

I don't know if the OEM Seadoo pump (from Airtex) had a relief valve. I have bench tested the OEM pump to over 160 psi and it was still climbing strong but I chickened out.

Thank you for the great information .. that grommet is not from Quantum. The 501 with new seals is still being shipped… I’m just experimenting with my original 342 as it’s really caught my curiosity .. I’m not sure where the grommet came from but I will drill a hole through it and see how I get on with it tomorrow.