Tool Review: Thompson Fuel ZAPP FSA

Fuel ZAPP FSA, by Thompson, is compatible with gasoline, gasoline-ethanol blends and diesel fuels. The tester measures fuel pressure, manifold vacuum and exhaust backpressure with large, readable gauges. Combined with an inline flow meter, this tool allows techs to identify any problems with the fuel supply, including the fuel pump, fuel pump check valve and inlet strainers, fuel filters, fuel pressure regulator, leaky fuel injectors, fuel aeration and contamination and restrictions in the fuel supply and return lines.

Also features:
• Complete set of Asian, European and domestic fuel line quick disconnects.
• 42-page illustrated fuel testing manual.
• TA Labs fuel volume calculator software that instantly calculates the fuel flow requirements for any gasoline engine.
• Full three-year warranty.


Bruce Lunsford, an automotive instructor out of Mooresville, N.C., found the Thompson fuel system tester saved time on diagnoses in the shop.

"It takes a lot of guesswork out of automotive diagnostics," said Lunsford. "A lot of techs depend on the scan tool instead of checking the basics of a car, and this tool actually goes in and checks the basics to confirm if there are any problems.

"If you have the fuel pressure, that means the pump's working. But if you don't have enough volume to run, it can cause excessive gas usage and other problems because it will make the computer compensate for lack of fuel; it will try to deliver more fuel. Today, inefficient is not a good thing.

"[The tester] was very easy to use. It did have a vacuum gauge on it. In teaching classes, the most forgotten tool is your vacuum gauge. We used it heavily in the early days to diagnose cars, and people got away from it. But when they have it all in one tool like this, it has everything you need … and it zeroes in on the problem."

Lunsford considers this tool a good investment for any shop—as long as it doesn't sit in the toolbox.

"When a person gets it, he has to use it," said Lunsford. "And after you use it, you can't do without it.

"It's a great tool … it should pay for itself in no time flat. It will make the tech look like a hero and give him a lot more follow-up."