2003 XPDI Need some Advice!!!

[Nodakman]

Alright that will help me out getting some more info .. My compression gauge is fairly new but as for the accuracy I don't know haha

I will definitely retest the compression just to see.

Oh and I was wondering on the manual for it is the one I have good enough or is the seadoo one that much better I should get it? And if so where should I get it from?

 

[68ragtop]

Google search seadoo manuals. One of the top hits is a site with free downloads. seadoo manuals .net I believe? Its the factory manual in scanned PDF format.

 

[Nodakman]

Ok that is the one I have so I'm good on that one

 

[Nodakman]

I first rechecked the engine compression and you were right, in flood mode the compression was a lot better 125 psi on both. Also in flood mode the air did not come out of the rail.

So after some close quarters wrenching I was able to get the air compressor housing out. Nothing looked to be broken or out of place. The cylinder walls were smooth and piston looked fine. I am really at a loss as to why there is no compression. Got any ideas?

 

[68ragtop]

The pictures are'nt telling you too much other than the reeds don't appear broken at least.
The slime in the pressure chamber is a little strange tho. I wonder if it ingested some water at some point recently?

The system works pretty simply. I would take the center bolt out & inspect & clean everything. Once you have it apart you can see how it works. The large reed allows air into the cylinder, but not out. The small reed on the other side lets the compressed air into the top chamber but prevents it from going back into the cylinder. The outside chamber is just the water jacket for cooling.

Did you verify that there are no leaks in the air line going to the rave solenoid? it should hold air pressure with no leaks at all when the valve is closed (normally its closed)

Also, see if you can manually turn the engine to verify that the piston is cycling though its strokes smoothly & there is no slop in it. there is nothing that keep the cylinder in place right now, so when the piston moves upward its possible it will push the sleeve up too. Just watch it close so it doesn't do that. If it goes too far up & doesn't come back down the rings will pop out of the cylinder & you will have to pull the PTO to get is back together.

The pump overall is a very simple design, you should be able to figure out what wrong fairly easily. See you got no pressure at all, I was expecting to see broken reeds, or a failed piston.

 

[68ragtop]

Soooo, Any new updates?

 

[Nodakman]

Yes I do have an update haha ! Work has been crazy and I didn't get to look at it till last night. Piston moved full stroke and smooth no slop. I took apart and cleaned all the air compressor parts and put it back together nice and tight. So with the small black line unplugged from the rave solenoid I put my finger over the end of the black line and turned it over in flood mode and she pumped up to 90 psi! Then it started raining so I had to quit. So now my thought of issue is the rav solenoid not working right, but because the rain i didn't hook the line back up to the solenoid to check. Are they known for failing at all? The oily goo in the air compressor could have got into it. I will check that all out tonight and let you know what I find out.

 

[Sportster-2001-951C-Stock]

Interesting subject, I wanna know what you discover.

 

[68ragtop]

The air pump piston does have an oil control ring, so its possible that there is a problem with that ring? There is also an oil return line that runs from the bottom of the air pump chamber (engine case) to the oil filler neck in the front of the ski. if you look under the hull, you will see two black lines hooked to the neck. The bottom one should be the oil return from the air pump. I would look at that & make sure its clear. if you hand turn the engine with the spark plugs out, you can usually hear pressure build below the piston & oil/ air will move back & forth in that line. It will make a bubling type of noise just from hand turning the PTO. I suppose its possible that the oil is not returning to the filler neck correctly?

I had thought you checked the black line going to the raves before, but maybe not? But your right, it should not pass any air at all when its not energized & it definitely needed to be taken apart & cleaned out anyway. keep us posted!

 

[Sportster-2001-951C-Stock]

I'm jealous, with that air pump you guys could plumb an air tank in the bilge and mount train horns on the bow.

 

[68ragtop]

I'm jealous, with that air pump you guys could plumb an air tank in the bilge and mount train horns on the bow.

I think your right.... Now that would surprise somebody at the dock

 

[Nodakman]

Update - so I hooked the black line back up to the rave solenoid and it pumped up to 90 no problem...taking it apart cleaning it must have done good... So I was thinkin alright it's gunna run .. No such luck ... It wanted to but just wouldn't go ... So a few things I noticed while trying to get it to run - I pulled a spark plug to try and get some fuel in the cylinder as this had worked before to get it to run .. When I did this I cranked until I saw fuel but then it tried to run on just one cylinder [emoji50].. Put the spark plug n wire back in and nothing. Tried this on both cylinders and with one plug in one plug out it would try and run.
Another thing was I heard a squealing ish sound coming from the fuel pressure regulator on top of the rail, also I could hear fuel going back into the tank once while it was quiet which is probly normal but I don't know.
So that's all I've got done tonight ... What should I try/check tomorrow

 

[68ragtop]

So now that your Air pump is pumping out the required pressure, check your fuel pressures again. If I remember right, you where dropping bellow 100? see if you have 27psi with power up, & see how high it climbs while you are cranking. As the air pressure builds so should the fuel pressure. It should climb up pretty quickly to 107 you could posibly have a regulator issue. I'm guessing the slime that was in the pump probably got into the regulators too. Did you happen to clean out the air line before you put it back together? Don't forget to make sure the oil return line is functioning too. It would be a bummer to find the problem only to have it happen again if you get more oil/moisture slime.

Your getting no maintenance light, or warnings correct?

 

[68ragtop]

fuel is returned to the tank at the top & dumped over the fuel pump baffle, normally this happens while its running so you can't hear anything. as the fuel regulator prevents the fuel from returning to the tank below 107psi /27 psi depending on the air pressures. I suppose you could hear something if you listened close to the tank, but I have never noticed. To check the air pressure regulator you really need to be Tee'd into the line just like checking the fuel pressures. unfortunatly more custom/special test equipment...

but I guess seeing you have what you need to check the fuel pressure see what you have there first. I am guessing its going to be low.

 

[Nodakman]

Did some early morning checking and here's what is going on ... Key on fuel pumps up to 27 and holds cranking brings it up to 78 psi and that's it .. It fired up one time and went up to 100 before it died but tried multiple times after that and all I go was 78 max at cranking.. Then I tried bleeding off the pressure and checking key on pressure and a couple times it shot up to 50 and 40 and bled down to 27 and held there .. It could have been air in the line but not positive ... Later I might pull the fuel pressure regulator and clean it to see if it makes any difference ... But most likely I'm probly looking at a fuel pump?

 

[68ragtop]

Ok, lets dig a little deeper....

If your cranking in flood mode, You might only see 80ish PSI. I didn't think of this before, but I think its because the air & fuel injectors stay closed & it messes with the regulators. This time, crank it over with the throttle in idle position. its going to inject fuel obviously, but you could remove the plugs, or at least the spark plug wires so it doesn't start.

Crank it over, you should see 107 PSI at cranking for sure. The needle will bounce erratically while cranking because of the slow cranking speed pulses of the air pump. completely normal, But you should notice the average of the "bounce" is around 107. As soon as you stop cranking it will fall back around 80psi. The system should hold that PSI & then very slowly drop back to 27ish psi. A healthy air system will stay pressurized after cranking & that will keep the fuel pressure higher during that time as it bleeds off. Eventually the pressure will drop back to 27ish when the air pressure is gone, provided your fuel system is holding pressure too. This drop from 80 to 27 shouldn't take seconds it should be minutes. Maybe 5-10 minutes? It should be very slow.

Try these things & post back.

 

[Nodakman]

When I checked it out this morning I did both flood mode and idle and the result was the same on the fuel pressure and when it got to 78 it slowly bleed off as you were saying.. But that was as high as it got ..

 

[68ragtop]

Sounds like your getting close to the problem. If its at normal idle & won't build to 107 there is a problem with either the air pressure regulator, fuel pressure regulator, or the fuel pump itself. has to be over 100 under normal conditions it it won't start. Now to figure out what part of the system is failing.

Hhhmmmmm...


based on your system having no air pressure before, it would make me think it's air pressure related, but maybe its on the fuel side. Seems odd to have problems with both side at the same time tho. I look at a few things in the shop when I get home today.

 

[68ragtop]

Ok, This intermediate pressure thing was bugging me so I went out to the shop when I got home & tested a few things. One thing I just realized is the fuel pump will NOT run when its in flood mode. I didnt know that. So scrap that testing procedure completely. Sorry for the misdirection.......

I took a DI fuel rail assembled it to a head to keep the air injectors in place & pressure tested it using my my shop air line. The air pressure regulator blows off right at 80 PSI. As I mentioned earlier, as the air pressure builds, the fuel pressure will increase the same amount.

So if your fuel is properly regulated at 27 PSI, & you add 50PSI of air pressure you will see 77 PSI of fuel pressure.

Somehow you need to figure out how much air pressure is holding in the rail. you might be able to put a gauge on the rave pressure line & measure it there. OR come up with some other way of connecting.

If the air pressure holds at 80, then I would suspect you have a bad fuel regulator, or fuel pump.


regulator sure would be a lot cheaper, thats for sure.......

 

[Nodakman]

So I was able to do some more testing and I think I have to be close to figuring it out ... Even though I don't think I like the reality. So I did what you did for testing the air pressure regulator and it released at about 80 so I figured that is working correctly. Also when I did this I checked the air pressure from the pump and got up to 80 like it was supposed to. And while cranking and trying to get it to run I had my fuel pressure gauge hooked up and was watching this as well. It would go to 27 w key on and anytime I cranked on it the highest I got this time was 76, 2 psi lower than last time. So my assumption is the fuel pump is on it's way out [emoji17].

To be on the positive side tomorrow I am going to take the rail apart and clean the fuel pressure regulator again, as when I did that the last time it actually ran haha.

With the knowledge that the fuel pumps are somewhat known for going out I think this is the issue. One more thing that really struck my mind as it being the fuel pump is that it would not reach 107 while cranking, which now knowing the specs it kind of makes sense. I had to watch a video on how direct injection works to better understand it. I could be wrong but I think with this direct injection the fuel pressure has to be higher/ able to overcome the compression of the cylinder? To me that makes sense for the fuel pump pressure being so high, so it would be a combo of the 107 fuel+50-80 air to be greater than the cylinder compression. Please correct me if I am wrong!
So tomorrow I am going to remove and clean the rail and fuel pressure regulator and see what happens and will report back with any findings!

 

[68ragtop]

One last thing you could do is monitor the return line from the rail. When you simultaneously have the 80psi on the air side & only 76 on the fuel side at the same time you almost have you answer. It has too be either the regulator or the fuel pump. If you could rig up a length on hose with a 5/16" barb on it, you could hook up to the fuel return line & verify that no fuel is flowing out while the pressure is failing the test. If fuel continuously flows during the cranking, its your regulator, if nothing comes out its the pump. A healthy pump can make over 150 PSI so, even at 107 there should be fuel flowing out the return line.

Another thing that is worth checking is making sure the fuel pump is actually running while its cranking. IT should be, but might be very hard to hear while cranking.

Lastly, if everything still points too the pump, I would pull it out & make sure your filters are not completely plugged up. there is one on the bottom, & one inside the baffle. These filters are replaceable & not expensive aftermarket. surprisingly most auto parts stores have them in stock. (part numbers are on this site somewhere)

Pulling the pump on a RX isn't too terrible. unplug the wire harness's that go to the the steering & get them out of the way. Pull the air horn (you probably did this already) and lastly remove the metal bracket that holds the air horn in place. Just be very carful of the sending unit, pretty easy to damage it as your working it out. Also, have a lot of rags nearby. The baffle will be full of fuel & will dump some as you tip it towards the front to clear everything. If your able, compress the baffle to help clear things. It's spring loaded & gets a little longer as you lift it up.

 

[Nodakman]

So I checked to see of I was getting any fuel out of the return line and got nothing key on or cranking.. So it's pointing to the fuel pump.
So in any case I needed to take out the assembly. The new bottom filter looked fine no junk in or on it. Then I took apart the assembly which I had not done the last time I took it out. And this is what I found-



The fuel pump is quite rusty and felt like a brick .. Are they pretty heavy in weight? ... Anyways then in the housing the other filter looked pretty bad I'm not sure if you can see it clearly enough in the picture but nasty and debris in the bottom as well...

So now I guess I'm gunna order a fuel pump. But because I'm short on moola I'm gunna try the high flow pump and see if I get lucky.
Sound like a good idea?

 

[Sportster-2001-951C-Stock]

So I checked to see of I was getting any fuel out of the return line and got nothing key on or cranking.. So it's pointing to the fuel pump.
So in any case I needed to take out the assembly. The new bottom filter looked fine no junk in or on it. Then I took apart the assembly which I had not done the last time I took it out. And this is what I found-

View attachment 27580View attachment 27581

The fuel pump is quite rusty and felt like a brick .. Are they pretty heavy in weight? ... Anyways then in the housing the other filter looked pretty bad I'm not sure if you can see it clearly enough in the picture but nasty and debris in the bottom as well...

So now I guess I'm gunna order a fuel pump. But because I'm short on moola I'm gunna try the high flow pump and see if I get lucky.
Sound like a good idea?

One problem with trying to find replacement pumps is many of them draw too much current and the charging system can't supply enough current to keep the battery from being discharged. So that might be an issue.

There's an 787/800 RFI ski thread somewhere here that lists which aftermarket pumps will work, sorry I don't have the link bookmarked.

 

[68ragtop]

While you have that apart, can you see if the check valve is still functional, & is it by chance plugged up? It's designed to pull the fuel up throughout the bottom filter via the check valve, then the return line fills the baffle to keep the pump submersed & cooler running. There's a chance the check valve is mucked up & its sucking the fuel from inside the baffle & emptying it. To really clean it out good & get to it, you need to drill out the rivets. however that "might" compromise the gasket/seal. pretty easy to make a new one if it happens tho.

Both of those filters can be purchase at auto parts stores. Advance Auto in my area has them in stock.

Not saying your pump isn't toast, but I would investigate a bit more. there's an outside chance you could fix it for $20. no promises, but it is worth going just a bit further to make sure.

 

[68ragtop]

One problem with trying to find replacement pumps is many of them draw too much current and the charging system can't supply enough current to keep the battery from being discharged. So that might be an issue.

I should but an amp meter on a pump and see what it draws at 107lbs. Never thought to test that.