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Often when an engine will not start the first thing to pop into somebody's mind is "it must be the fuel pump". I often have the same train of thought. And many times replacing the fuel pump is the answer to a no start condition.
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Electric fuel pump

But the percentage of times that a fuel pump will cause a cranking no start condition is most likely less than 25% (just educated guessing).

I suppose the actual failure rate of the fuel pump would be determined by year make and model of the vehicle.

But because the fuel pump is so often replaced before pinpoint diagnostics are performed I thought that I would discuss the subject of how a fuel pump circuit works.

Fuel pumps and no starts

Vehicles for around the last 20 years have in tank mounted electric fuel pumps. So this will be the type of fuel pump I will discuss in this short article.

Electric fuel pumps and circuits will vary greatly depending on the vehicle year make and model. Most of these fuel pump control circuits are tied to the vehicles main computer.
 
 
Car noises such as squeaks and rattles are at the top of the complaint lists from consumers that purchase new automobiles. Working as a line technician at a dealership for 20 years much of my time was spent hunting down these annoying sounds.
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Car noise help button

In the 80s and 90s sub frame vehicle construction was not as solid as they are today. Squeaks and rattles are complained about less today then just a few years ago.

As a mechanic or even a vehicle owner trying to hunt down one of these annoying sounds directional hearing skills will be your most effective weapon.

This page will discuss types of sounds that your car will make and help to dissect the noises to send you in the right direction to solve the problem. I would like to start off with an example of a rattle and squeak on my own personal car that drove me crazy and was difficult to find.

Squeaks and rattles on my T/A

It's funny that I have to go back so far and talk about my 1979 Trans Am, but this was a challenging car noises to find. My Trans Am was a sub frame car that was built in the days when this technology was relatively new. The torque of the big block 6.6 L engine and the fact that the car had removable T-tops made the entire car weak.
 
 
Still snowing in your area? When it warms up you may want to know how to find auto ac freon leaks. This would be one of the most common problems causing the Ac to blow warm after a long winter of not using it.
 
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UV leak detector
A dirty sticky spot on an ac line or fitting should catch your attention. The Freon contains the oil charge necessary to lubricate the compressor.

The presence of oil around and AC fitting or line is a strong indication of freon leaking. My first step in most auto repairs including auto AC leak diagnosis is to perform a solid visual inspection of the entire system.

Although this is always my first step for diagnosing Freon leaks it is not always effective in finding the problem.

In fact, this visual inspection will only uncover large to extremely large leaks. And by far the most common car AC problem would be small leaks that allow Freon to escape over long periods of time.