Yam911 - VZ250TLR starting issue

[Tx Champ]

VZ250TLR Mfg date 11/06, ~140hrs – The engine will crank over, but will not fire. I’ve checked for and have spark on all cylinders using an inline spark detector. I have gas in the cup filter under the cowl. With the cowling off, I don’t hear any pumps pressuring up the fuel system when the ignition switch is turned on. I put my ear to the VST when an assistant turned the key on. What can I do to troubleshoot the fuel system to make sure it is getting to the injectors and they are firing?

[yam911]

The electric fuel pump in the VST should run for approximately 3 ~ 5 seconds when the key is first turned on. A pressure gauge would indicate that the pump is running and pressure is being built up.

If you don't hear or feel the pump run then verify that battery voltage is being applied to the pump when the key is on. Jumper the ground side of the pump to a known good ground to see if the pump is working or not.

If shove comes to push you can remove an injector and crank the motor to see if fuel sprays from the injector.

[Tx Champ]

Thanks for the feedback ... I'll get it back in the garage and give those a try in the morning before it hits 100

[21XDC]

My guess is a bad fuel pump relay... Seen this a bunch including my motor.

[Tx Champ]

Checking voltage at the top of the VST, I have ~10.5v on both the red and blue wires to ground. Tells me the pump is not running. The schrader valve, is it just going to have air behind it or fuel? Was going to stick an air gauge on it to see if there was pressure there.

[201pro]

You need a fuel pressure gauge. It will have fuel.

[Tx Champ]

You need a fuel pressure gauge. It will have fuel.

Thanks! Took a small Phillips and pushed in the core ... no pressure.

[Tx Champ]

Update, I had to make up a couple of alligator clip leads. I found a better ground and voltage at the pump is at cranking battery potential (~14v batteries were on charge). Shorted the blue wire to ground and the pump ran. Let it run for about 5 sec thin hit the starter and it fired off, so question is how does the blue wire get to ground potential? A pressure switch?

[skeeterBill200]

I`m betting its the relay pump too

[skeeterBill200]

relay switch

[Tx Champ]

Losing too much time, so broke down and ordered and downloaded the online service manual. So after YAM911's recommendation to jump the ground side of the pump to test it, the next step is to troubleshoot the fuel pump relay. Thanks 21XDC & skeeterBill200 for that heads up. But Terry, just a FYI that a relay and a switch are two different devices. A techie like me can't help but point those little things out ...

[Tx Champ]

Y'all nailed it! But the issue was self inflicted. I changed out the water pressure relief valve about a month ago, so had to unplug the relay. I guess I didn't get it snapped back in good, cause it was unplugged when I pulled it back apart. Funny thing is, the boat had been run 2-3 times since the relief valve replacement, so guessing I didn't get the plug latched when I plugged it back in.

[yam911]

Is your problem solved or not?

[Tx Champ]

Yes sir, thanks for getting me started in the right direction

[yam911]

Good.

[Tx Champ]

Refer back to post 12 for the fix.