Looking for some help, 2002 x20 not running.

[Jtatro11]

Hello everyone, new to the forum hoping to find some help and answers to my problem. Last summer my x20 shut off in the middle of the lake while towing a tube. At first while trying to restart engine would just crank and crank. Eventually after getting the attention of another boater we were towed back to camp. After doing a basic check of fuel levels, oil levels, and battery voltage i gave it another shot and it cranked over and started however would run for one to two seconds and shut off again. Well I have finally brought the x20 home from storage and started testing the fuel system. I downloaded the service manual last night and have completed all of the tests for the fuel system. I just wanted to see if anyone has any insight to my problem or can lead me in a direction of tests i can perform to narrow down the issue. Like i said the engine will fire up every time but only run for one to two seconds and then dies, it does this every time. Would any of the sensors cause this issue.

Thanks in advnace

John

 

[poppie]

Sounds like the high pressure fuel pump. Its located inside the vst on the port side of motor. Turn the key to the on position and put your hand on the vst. If the pump is running uou can feel it. There is also a fuel prussure test port on top but you need a gauge to read it. If you have one fuel pressure should read 34psi or so.

 

[Jtatro11]

Thanks poppie, however the high pressure pump tests out fine. Holds 34 psi while cranking. I’ve completed all fuel related test and everything checks out.

 

[poppie]

It could be a line sucking air somewhere. When my fuel pump went it was very intermittent. It would run fine then suddenly die. Have you checked the fuel tank for vacuum? There are so many variables and i know first hand how frustrating it can be to chase them all down.

 

[Tim75]

You need to make the usual checks- trigger coils, compression (all six), dreaded throttle position sensor. When the tps fails, it fails, it fails in full rich mode. Rich enough to flood the engine. It may start in 30 minutes or so.

I have had wires to VST break. Stationary, they were OK, bouncing around, they were intermittent.

Check the kill switch-- the rubber on the cap fails and will not hold. Do you have a throttle guardian? How old are your spark plugs? Sometimes they develop internal shorts.

There are 4 fuel filter/strainers on the engine, beginning on the fuel pickup in the bottom of tank. Next is on the lift pulse pump. Next is the white filter, looks like an oil filter. Next is in the bottom of the VST. Do you have any old gray fuel hose? It was known to have internal issues that could clog the hose.

 

[Jtatro11]

poppie thank you for your input, how would i go about testing the fuel tank for a vacuum? I wasn't able to find any tests on this in the service manual.

Tim75, also thank you for your input. Kill switch is working fine, engine will just crank with the safety lanyard un hooked, re attach and engine will fire and run for one second and then die. I also tested the TPS this morning and from what I've read, when testing with and ohm meter as long as the ohms change smoothly on both outer pins through the full range of throttle the TPS is in working order. Im going to buy a gauge to test compression today and also begin testing the triggers. I did pull all of the plugs and i have spark at each one, the plugs did look like the engine is running rich.

Thanks again for the help. Also if there is any one else out there with any insight it would be greatly appreciated. At this point I might have to empty my wallet and take it to a mechanic because I'm stumped.

 

[Tim75]

Back to the kill switch-- Have you tried holding the rubber cap in place; as in gently pushing on it? Have you checked the wires to the switch? Including back at the engine. Follow wire colors.

With 2 people-- one cranks engine, other holds hand on vst. CAUTION! This is to answer this: Does the pump continue to run or does it stop? If it stops, start checking wires.

Running for 1 second is a puzzle. Usually it will either run longer or not at all. Even if running rough.

TPS is best tested with analog (needle pointer) meter. Yes, as long as needle moves smoothly it's OK. Test center term. to each outside term. Hope it's good; they are >$500.

 

[poppie]

Just open the fuel cap. If you hear a whoosh of air then its vacuum locked. Then you would need to check the vent tube.

 

[Jtatro11]

Need some help, after realizing that fuel was not my issue I began testing the ignition. I assumed since I had spark that wasn’t the issue. Side note This motor when it’s not warm always took one or two cranks to start. So while checking the spark today I noticed that I only had spark some of the time and that when the engine did try to start the spark was dropping out causing the engine to only run for a few seconds. Well today while doing the CDM trouble shoot I figured I’d look into my lanyard/kill switch. So after tracing wires back and forth, i tried something. if I disconnect the black/yellow wire that runs down into the main harness and runs to the front the engine starts right up and runs great however my lanyard doesn’t work any more. I can shut the engine off by turning the key off but it takes a few seconds. If I reconnect the black/yellow wire it won’t start. My problem is the test says to check for continuity with the ignition on, well when I do that it test fine, However with ignition off it does have continuity. Is that how it should test?

 

[Jtatro11]

This is the black/yellow wire. Unplug starts and runs fine. Plugged in may start but only for a one second at most. If I plug it back in while engine is running it shuts off

 

[Jtatro11]

Traced the wires more and turns out the throttle commanders black yellow wire was causing the issue. What other components does the throttle commander control. I simply cut the black yellow running to the throttle commander and plug everything back In and starts first crank.

 

[Tim75]

Traced the wires more and turns out the throttle commanders black yellow wire was causing the issue. What other components does the throttle commander control. I simply cut the black yellow running to the throttle commander and plug everything back In and starts first crank.

I cut my throttle guardian wire 3 years ago, and never looked at it again. It sounds like yours is dead.