I'm mechanic of 20 years

Jul 26, 2023

AN experienced mechanic has revealed his five-minute test to see why a car won’t start.

David Long, known on YouTube as Car Wizard, showed that this test involved no expensive tools or computers.

Long, in a recent video, said he only has to use a bottle of starting fluid to give him five possible answers.

He said: ”When a car rolls into the shop crank no start I can answer 5 questions in one minute with this bottle of starting fluid.”

Long demonstrated the test with a 2006 Audi TT Quattro with a 1.8 turbo engine that was brought in when it stopped running and wouldn’t start.

The car expert added that this problem can happen to any car.

Long proved this by explaining a Lotus was also in his garage with a no-start condition.

He said: “When a car comes into a shop with a no start condition I can usually get to the bottom of why it won’t start in about 10 minutes with zero scan tools, zero computers.”

The video showed Long getting into the car and attempting to start the vehicle multiple times with no success.

Long said there are three questions he asks himself in this situation.

He added: “Is it A: crankshaft position sensor?

“Is it B: a fuel pump issue?

“Or is it C: a bad computer?”

The car experts first step was to spray a very small amount of starting fluid into the engine's intake tract, in the hood of the car, and then start the engine to make sure the fluid goes into the engine.

In the video, the engine started.

Long said: “Did it start? Yes. If this engine is just given some fuel it will run.

He added that at this stage he can answer five questions.

Long said: “It is a bad computer? Not likely.

“Is it a bad crank sensor? Nope

“Is it a bad cam sensor? No.

“Is a timing chain or timing belt or something like that broken or something's wrong with low compression? Nope.

“Is it an ignition system problem? Nope.”

Long added that this test showed that the car will run if it gets fuel, so the issue is that the engine is not receiving the fuel.

To do this he carried on his tests in the fuel pump area.

Long checked that the pump worked by using a power probe to apply pressure to the pump.

He then showed how he used the ground on his power probe and connected it to the power probe tip.

Long said one of three things could happen: You could hear nothing, a whirring noise, or a clunking noise if the car is severely locked up.

The video showed the fuel pump making a knocking noise, which demonstrated that the car was severely backed up.

Long then checked the fuse box and showed viewers the blown-out fuse.

To solve the problem, Long replaced the fuse with a new one.

Long added that, although obvious, drivers should make sure their car has gas as he has seen this happen before.