Out of things to fix on 1998 DF70 Suzuki

[alexedit]

Hey guys -
ok, so the problem started about a month ago when I was going half throttle a motor just shut off and it wouldn't start.

That turned out to be the connector on the vapor separator tank (VST). The connector was not sending power to the pump.

I bought a good used vapor separator on ebay and a new fuel pump. That worked...BUT

Now the motor behaves like it's starving for gas. It has only about 30% of the power.

Here's the crazy part, when I crimp the return line that goes from the fuel pressure regulator back to the vst, the motor runs perfectly fine. What in the world is going on? :/

I thought it was the fuel pressure regulator located on the bottom of the fuel rail so I changed it....no luck.
Any ideas?

Thanks in advanced

 

[alexedit]

Any thoughts?

 

[iamsaws]

I have a similar issue with 1998 Df70. Mine would work perfectly, but would randomly just shut down when in upper RPMS. I could usually get it started again, but my day was over. Frustrating is right, because it happens random and you have to run it pretty hard. I haven't got to the VST tank yet, I will look into that. I have read online that people have added an inline external fuel pump low psi 2-5 instead of a primer bulb . Honestly I don't know. Vapor lock is an issue with these motors from what I have read.

Thanks for the help. I ll keep in touch with any info I find.

I actually had to buy back my old motor and put it back on... Probably no more suzukis for me.

​good luck

 

[schematic]

possibly injectors plugged/restricted