07/08/2025
Water in Your Fuel Might Not Be Where You Think It Is!
We’ve had a few rigs come in recently with weird idle issues, mid-range stumbles, or just plain random behavior.
No codes. No visible water in the separator.
But the problem? Water in the fuel system—just not where most guys look.
🔍 Here's What You Need to Know:
Most folks check the fuel/water separator and think,
> “It’s dry, so I’m good.”
🧠 But here’s the deal—on newer EFI motors, especially with VST (v***r separator tanks) or return-style systems, water can settle in:
The VST reservoir
Injector rails
Fuel pump cavities
And none of that water shows in the clear bowl of your spin-on filter.
⚠️ Symptoms of Water Contamination (Even When It “Looks Clean”):
Mid-range stumble or hesitation
Rough idle or hard restart after shutdown
Power drop under load, no alarms
Engine “sputters” but recovers after a few seconds
It can look like spark, injectors, or timing—but it’s just contaminated fuel tucked deeper in the system.
🛠️ DIY Tip:
Drain a sample straight from your VST drain screw if equipped
Use a clear glass jar, let it sit, and look for separation
If the fuel looks hazy, has bubbles, or you see separation → time to flush the system
If you’re not comfortable draining or purging the fuel rail, no sweat—we’re glad to do it right and prevent bigger issues down the line.
💬 We post stuff like this because we love helping guys figure out small problems before they turn into big ones.
If you need help tracking down weird stumbles, random fuel issues, or just want the whole system pressure tested and cleaned—we’re here for that too.
EMT
Livingston Texas
936-239-1209