DI fuel pump issues

[glfolts]

Hi All,
I have a 2002 gtx di. After winter storage, I added new fuel and started up. If ran fine for about 2 hours and then died in the water, managed to get it started and limp back home, running rough and taking it slow.
Pulled the ski and It would start fine and then run rough with dark smoke after a few minutes. Idled OK, but sputters at higher RPM.

I first checked plugs and compression. Plugs looked fowled and compression is a bit low, but even. (115PSI). Installed new plugs.

Next I focused on the fuel and supply. I do not have the seadoo fuel tester to see if I have the 107 PSI. I pulled the fuel pump assembly out so I could check the filters. The filters looked very plugged and there were many insect body parts inside the fuel reservoir (the tube the pump sits in). I replaced both filters, cleaned out the tank and both parts,

After reinstallation the ski will not start. It cranks, runs if fuel is dumped in cylinders, but seems like it is not getting fuel. Maybe the main filter is plugged, pressure relief valve is bad, or I have a bad fuel pump. It looks like the DI uses a very special pump........

So I now feel I need to get my hands on the fuel pressure tester.
A) does anyone have any other suggestions
B) does anyone have a parts list to build one from autozone parts (what size is the quick connect, what type of fittings are available????)
C) I saw somewhere that someone rents the tester out???? Any contact information?
D) could I tell anything if I pull the fuel rail and injectors?

Thanks for the help, I will post my results

 

[Coastiejoe]

Fuel pressure is CRUCIAL with DI skis. But compression is important will all skis. Your compression (assuming your gauge is accurate) is too low. Especially true with injected engines. It simply can't get enough compression to fire the amount of fuel entering the cylinders.

 

[68ragtop]

The DI's are definitely more compression than the carb'd versions. It should be in the 140-150 range.
IF both are right at 115, I suspect you have a bad/poor quality gauge.

 

[Quasar50]

For the fuel pressure tester, you are looking at about $100 in parts. Autozone carries most of the parts you will need. All fuel lines / fittings are 5/16". I got the male and female quick disconnect ends. For the male end I got Dorman 800-159, which has both the 5/16 and 3/8 double male end steel lines ($18.99). For the female end, I had to get Dorman 800-057, which is a nylon 5/16 line repair kit ($19.99). You will also need some 5/16" high pressure fuel line (I got 4 ft at $4.09 per ft). Finally you will need a compression tester gauge ($25.99). The rest I got from Lowes (brass fittings to tie the parts together). I got a needle valve to regulate flow when testing the pump by itself (Watts LFA-41 - 1/4 OD x 1/8 MIP), a brass T (Watts LFA-704 - 1/8 MIP x3), and 2 brass nipples (Watts LFA-715 - 1/8 MIP x2). All told around $20 at Lowes. You will also need hose clamps to secure them. Attached is a pic of the final product.
I designed it such that the guage can be read while riding the Doo if necessary (long gauge hose length).
To give props, it is based on a design DooWacka posted in this thread:
http://www.seadooforum.com/showthread.php?46680-DI-Seadoo-Fuel-Pump/page4

 

[Quasar50]

Also, as an FYI, I believe it's best to fill the tank as full as possible and add stabilizer when winterizing. This prevents any condensation from getting in the tank, which will corrode the pump over time. I try to fill the tank between uses as well just in case I don't go out for a month or so. The previous owner of my Doos did this as well, and the pump is still strong (as evidenced by the 120-130 PSI tested on the old pump). As to why the seal gave out, I guess I'll mark it up to rubber degrading over time combined with the high pressure of the pump.

 

[glfolts]

Thanks guys! I built the fuel tester and eliminated the fuel issue. 27/107 like I should have.

I ran further tests and ran the ski on one cylinder at a time ( plug grounded out on other cylinder). Ran fine on back (pto side), but would not start on front. Next I swapped all identical components from the two cylinders (fuel injectors, direct injectors, rave valves, coils, coil wires....). All no change.

Finally I saw your advice and retested compression

When I retested the compression, I found it even lower (90). Next I pulled the head and the news is not good.
Mag side piston top ring broke apart and tore things up

So now I need to get the cylinders bore, new pistons, rings and such.

A few questions for the experts:
1) what can cause this? Does the ring just wear and break or is this typically a deeper issue. I have always used seadoo synthetic oil. Is there a way to test the mixture?
2) how do you remove and insert the piston pin. Manual talks about heating to 120 and using a pin extractor. Is this needed?
3) I found a few guys on ebay that bore and Match piston ring size (looking at "full bore" ebay seller fullboreonline). $349 to bore, match and supply rebuild kit. Any thoughts on vendors or best path?
4) Do I need a compression tool to reinsert rings? A standard one from auto zone?

Thanks all for the help!

2002 gtx Di

 

[glfolts]

Additional picture



Here is another shot of the damage

Ps. I must have gotten something into the fuel pump. After changing filters, it would not start at all. No pressure. I bought a used seadoo pump on ebay and then got the required pressure. BUT I was now back to the original issue.

So to recap.

Running rough
Found debris in tank and seemingly plugged filter
Replaced two filter in tank
No pressure at all
Replaced pump
Got correct pressure 27/107
still had same issue (running rough
Found bad front piston an cylinder

 

[glfolts]

bumpity bump

 

[DooWacka]

A few questions for the experts:
1) what can cause this? Does the ring just wear and break or is this typically a deeper issue. I have always used seadoo synthetic oil. Is there a way to test the mixture?
2) how do you remove and insert the piston pin. Manual talks about heating to 120 and using a pin extractor. Is this needed?
3) I found a few guys on ebay that bore and Match piston ring size (looking at "full bore" ebay seller fullboreonline). $349 to bore, match and supply rebuild kit. Any thoughts on vendors or best path?
4) Do I need a compression tool to reinsert rings? A standard one from auto zone?

2002 gtx Di

You probably have your solution by now, sorry I didn't see your post until now.

There are usually three things that can cause the piston melting and ring mangling etc.
1) You used non-premium fuel, AND the knock sensor is bad, so the MPEM didn't correct the timing for the low octane.
2) The DI is running lean, so it gets hot and starts "pre-ignition". Lean can come from not enough fuel from pump.
3) Running at WOT to long without backing off and allowing cooling time. Seadoos don't have a thermostat like a car to regulate the flow of coolant, they just have a calibrated orifice that can only give one level of cooling for "general" running around.

Top end problems like this in the DI are usually not related to not enough oil. Lack of oil shows itself first in the bottom end with bearing failures.

Piston pins are usually fairly easy to remove without their special tool or any heating. Most OEM needle bearings are loose and not in some plastic cage, so extreme care should be taken to keep them out of the crankcase. Always cover the case with plastic or cloth to catch stray needles and circlips. Some replacement bearings come in plastic cages. When re-installing OEM needles you can use grease to hold them together while inserting the pin. I use the old pin (or a fabricated plastic pipe) to hold all the bearings in the piston, then just use the new pin to press out the old pin and "capture" the rod. The circlips can be tricky but doable with a couple of needle-nosed pliers.

Make sure rings are aligned in their grooves with the small pin that keeps them from rotating. Then with plenty of oil, some people can just use their hand to compress the rings to go into the cylinder bottom (since it is tapered to help). I have used a hose clamp over some thin sheet metal wrapped around the piston to compress rings.

Sometimes one piston is fine when the other melts. So, I have rebuilt only the bad one. The cylinder sleeve is usually bad where the mangled rings gouged and grooved it. To keep the pistons the same size, I get one new STD size piston and replace the damaged sleeve. The sleeve virtually falls out if you heat the cylinder in the oven at 350 for about 30 minutes. If you are quick enough, you can pull the new one from the freezer and insert and align it to the exhaust port without having to re-heat the cylinders. Depending on the sleeve you will probably have to get it bored to the new STD piston size. At minimum it will need to be honed. DI 951 pistons are about $75, and sleeves about $85 on eBay.

 

[glfolts]

Thanks for the detailed reply! As you suspected, I have moved on with a complete engine rebuild. Upon further inspection, I found that the bottom end bearings were bad, very bad. Missing balls and separators in both front bearings......

I decided to go with a rebuild, with 2 year warrantee at Seadood Engine Shop.

 

[glfolts]

Rebuilt by Tom at Sea Doo a Engine shop. Quick turn around and a great price. Installing now, but the seem to have done very well