My engine will not start up?

That one second burst from the fuel pump is to insure the pressure is up for starting. That will produce pressure in the fuel supply system but it doesn't mean the pump is running during cranking. If the injectors aren't pulsing during cranking there won't be anything to bleed that pressure down. That's why pressure in the system is misleading.

The place to start is by determining if the automatic shutdown (ASD) relay is turning on during cranking. The easiest way to test that is to measure the voltage on the feed wire. That will be the same color wire at all of the injectors. A test light works better than a voltmeter. You should see voltage there for one second, but what's important is if that voltage comes back during cranking. If it does not, suspect the crankshaft position sensor or camshaft position sensor. If you have a V-6 engine, the distributor is the most likely suspect.

Heading out of town soon. Will check back with your progress in the evening.

Hello, I'd use a gage and check fuel pressure, maybe the pressure bleeds off during the night? How long since a tune-up?

I'd use a fuel pressure gage and check fuel pressure. You might be able to check for trouble-codes, if there are any, by cycling the ignition switch, on --off, on--off, on, you turn the key till the dash lites come on, no further. The check engine lite starts flashing, you count the flashes to get the codes. I'm not positive that will work on your model year? It won't hurt to try.

If a 2.5L is not starting there are not too many things you can do except check to see if the timing belt may have broken or jumped, this will do all the symptoms you describe, it should show some oil pressure movement, but I wouldn't rely on it though, as it needs full starting rpm's to give you an accurate reading. With over 200,000 miles it may be low already. If you can get a hold of a scanner and plug it in, it will read no crank or cam sense, you could take a cover of the front, either side, mark it and have a friend turn it over, if it turns then you must check the alignment, I am moving to this mostly because of your high mileage, I don't want you to start spending time and money because repair parts are expensive. All the belt and alignment information is here, and so is an inexpensive scanner that may help you for years to come.

The fuel pump gets turned off when the engine is not rotating. Even if it did stay running, the injectors are not being pulsed, so the fuel would just get pushed through the pressure regulator and go back into the tank, just like when the engine is running.

It is possible for the fuel pressure regulator to leak through the internal diaphragm, then into the vacuum hose and get sucked into the intake manifold, but that would cause really poor engine performance with lots of black smoke from the exhaust. A better suspect is a leaking fuel injector. That typically will not be noticed while the engine is running, but once it is stopped, the fuel will leak into the intake manifold and usually into that cylinder.

The clue to a leaking injector is you will find that leaked fuel in just one cylinder. From there it will seep into the oil. To verify the fuel is going somewhere, connect a fuel pressure gauge to the test port on the fuel rail, then watch if the pressure drops when the engine is stopped. It should hold for days, if not weeks. With a leaking injector, pressure will drop within minutes to perhaps as much as an hour.

Once you have verified fuel pressure is dropping, use a small hose pinch-off pliers to pinch the fuel return hose where it is rubber between the fuel rail and the body. If the pressure is dropping because the regulator is leaking, it will not drop while that hose is pinched. The problem with this story is with a leaking regulator, the fuel will just go harmlessly into the tank. You are finding fuel in the engine. The regulator will not cause that unless it is through the vacuum port, but you did not observe the associated running problem.

The first thing I would try is a good hour-long run with fresh gas. Almost all brands of gas have plenty of detergents and other additives that may start to dissolve any varnish build-up in the injectors. Over time the injectors may start to seal better. I normally do not expect fuel system additives or cleaners to do much because they are just a quick shot of highly-concentrated additives already found in gas. Every time you fill the tank with fresh gas, you are getting the same cleaners at a lower concentration, but continuously.

If the car was parked six years ago because of this fuel problem, you have to look at the rest of its history. If it was driven regularly, an injector may have just decided it I is time to leak. That is not terribly common. If the previous owner drove in such a way that a tank of gas lasted for a coupe of months, there could be varnish built up inside otherwise good injectors. Replacing the injectors would solve that problem right now, but regular driving might also solve it in short order.

Sounds like fuel pressure is bleeding off through a leaking fuel injector. This happens on my Caravan with 378,000 miles. The solution has been to turn the ignition switch to "run" and wait a few seconds until the fuel pump turns off, then crank the engine. That couple of seconds is enough time to build fuel pressure in preparation for starting.

Caradiodoc

Hello, I'm Danny.

The first thing you should do is perform a fuel pressure test. If you don't have access to a fuel pressure tester most auto parts stores have a tool loaner program and can rent you one. Here is a tutorial showing what is involved for testing fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

The fuel pressure specification for your Avenger is 47-50 PSI. After performing this test get back to us and we'll go from there. Hope this helps and thanks for using 2CarPros.