2001 gtx 951di fires then dies immediately

[Junker907]

So I have a 951di that I actually took out of the jetski and I put into a 10ft aluminum mini jet boat....the ski ran fine when I took it apart and now it fires right up every time you push the button and dies right away....I have taken it to the dealer and they scanned it and tps out of range was the only code...I know these have fuel pressure issues so first thing I ordered filters and and new pump right away....I have tested fuel pressure and when I plug the key in first off it's about 22psi and when it fires it goes up to about 100 but just cranking on it it's not even close....if I pinch off the return line the pressure jumps to 150psi....I have checked for air leaks and checked air pressure which is just over 80psi....could it be regulators??? Could it be injectors? Direct injectors?? Mpem??? I have spent days and days working on trying to figure this out and don't want to just start throwing parts at it if someone has a good idea that it could be something I could have missed....I have ohm tested fuel injectors and they are both the same and both the direct injectors and one was 1.3 and the others bounced between.9-1.0 and spec is 1.0-1.6.....any help is greatly appreciated it has been a real bummer spending 400hours building the boat for it to not run! I have a short video of what it does but won't let me upload

 

[mikidymac]

What fuel pump did you buy. 99.9% of the aftermarket ones will not work just like you are describing.

 

[Junker907]

I bought the highflowfuel one that is specifically for the di and that's why I checked the pump on its own loop....it is almost like the regulator isn't holding the psi and I tried a different used regulator and same issue

 

[mikidymac]

All I can tell you is everyone that has tried the aftermarket fuel pumps has gone back to the OEM one.

 

[Digdog]

There is another member with a four stroke that is doing exactly the same as your doo, he is buying a Candoo to diagnose his problem. I thought it was either the TPS or the TOPS causing it, his name is JimmyJimmy. Maybe watch his thread in 4 stroke forum or get a hold of him. What did the dealer say about your TPS, did they reset it?

 

[mikidymac]

There is another member with a four stroke that is doing exactly the same as your doo, he is buying a Candoo to diagnose his problem. I thought it was either the TPS or the TOPS causing it, his name is JimmyJimmy. Maybe watch his thread in 4 stroke forum or get a hold of him. What did the dealer say about your TPS, did they reset it?

The DI is it’s own animal and nothing like a 4 stroke. You are correct though as the candoo is a great tool for the DIY DI mechanic.

 

[Junker907]

There is another member with a four stroke that is doing exactly the same as your doo, he is buying a Candoo to diagnose his problem. I thought it was either the TPS or the TOPS causing it, his name is JimmyJimmy. Maybe watch his thread in 4 stroke forum or get a hold of him. What did the dealer say about your TPS, did they reset it?

Yes and that didn't change anything

 

[jhjesse]

Pressures are too low to sustain a running ski. Replace the fuel pump with OEM and you will be fine.
When you install the lanyard fuel pressure should go to 27 not 22 psi. You need that extra 5 psi.
When cranking 27 plus 80 air pressure equals 107 psi.
If pressure is at 100 psi, it is too low to accelerate from idle.

 

[Junker907]

Well I dropped it off at the dealer because I ran out of time to mess with it so I hope they can figure it out

 

[mikidymac]

I wish you luck. Most dealers have no clue how to fix the 2 stroke skis anymore. All they want to do is hook the computer up to a 4 Tec and have it tell them what's wrong.

 

[kevrock]

I called a bunch of dealers to look at my 2001 GTX DI and all said they don't work on anything over 10 years old. Pisses me off because i bought it new from them.

I also did the aftermarket fuel pump and it did not work, sucked it up and bought new OEM and works great.

 

[Junker907]

I called a bunch of dealers to look at my 2001 GTX DI and all said they don't work on anything over 10 years old. Pisses me off because i bought it new from them.

I also did the aftermarket fuel pump and it did not work, sucked it up and bought new OEM and works great.

What was yours doing before? Something similar? My dealer is leaning towards mpem so used is like 400-600 and new is 2200...I wish I could find one I know works before wasting the money on mpem then have to buy oem fuel pump

 

[mikidymac]

Did you verify the needed 107psi fuel pressure?

 

[Junker907]

Did you verify the needed 107psi fuel pressure?

They said they double checked everything I checked

 

[Digdog]

On the 4 stroke that was doing the same thing his MAP sensor was suspect, when he unplugged it it ran fine. Try unplugging yours and see what happens, he had no code on his display but a candoo eventually showed a problem. There may be a test for it also, but I am not sure on the procedure.

 

[jhjesse]

JMHO
As an owner of four DI skis I can tell you first hand that aftermarket pump is not maintaining enough pressure to run only start and idle. You need to replace it with an OEM pump. Ask me how I know........
Just looked on eBay and there are several used pumps available. I would get one along with the new internal filters. They are also available on eBay next to the pumps.
When you receive it, clean it up good and replace the filters making sure the washers in the bottom of the pump go back in exactly the way they were taken out, otherwise the pump won’t pull fuel properly. Replace the canister filter with two heavy duty stainless hose clamps and a wix 33095 inline filter.
Hopefully that will get you going.

 

[Digdog]

I would suspect the fuel regulator if you pinch the line and it goes to 150psi, use a factory fuel filter as they are designed for high pressure, the wix is not. When the regulator and pump are working properly it should hold high pressure when the key is installed.

 

[kevrock]

What was yours doing before? Something similar? My dealer is leaning towards mpem so used is like 400-600 and new is 2200...I wish I could find one I know works before wasting the money on mpem then have to buy oem fuel pump

Mine would not run with the 100 psi fuel pressure. New OEM pump and 107 psi and it runs like new. The aftermarket pump may also draw too many volts and not let the ski run as well.

 

[jhjesse]

I would suspect the fuel regulator if you pinch the line and it goes to 150psi, use a factory fuel filter as they are designed for high pressure, the wix is not. When the regulator and pump are working properly it should hold high pressure when the key is installed.

When you pinch the hose between the gauge and the Regulator on the fuel rail, it doesn’t tell you anything. You are only increasing the pressure on the gauge upstream while the fuel regulator is down stream being restricted.
Been wrenching on DI’s for several years now using the inexpensive METAL wix filters with great success. (About 8 bucks vs OEM at 80 bucks) All the canister filters I have taken off were full of water and restricting flow. For 8 bucks a year you have unrestricted fuel flow that WORKS.
It has been proven over and over again that the after market pumps don’t work. The OP changed to aftermarket and now has problems. Simple deduction.
All advice and ideas are welcome...especially the right ones.