My car starts rite up then dies after a few minutes.and i just changed my fuel pump and filter and relay and its still doing it what is the problem?
I cannot tell you what is wrong without diagnosing the problem. However, I can do this:
Let me give you a little "Automotive Technology 101". The first thing you need to do is to check what is missing when the engine dies. A gasoline powered, internal combustion piston engine needs 4 basic things to make it run:
1. Volumetric Efficiency (built into the design of the engine)
2. Air-Fuel Ratio
Running out and replacing parts without first determining which of these things are missing from the equation is usually a waste of time and money.....your post bears witness to this statement.
The engine will not run at all if there is a serious problem with Volumetric Efficiency, and it takes an engineer to design and fix that anyway. It is not likely to be a compression problem if it starts and runs ok before it dies. So that leaves us with spark and air-fuel ratio.
So the next question is whether it is fuel or spark or BOTH at the same time? There are several things that can possibly affect each of these. Several possibilities can be either verified or eliminated by answering this simple question.
It is important to realize that BOTH of these things (spark and fuel) are controlled by your onboard engine control computer. To attempt to diagnose these things while ignoring the computer that controls them is usually a real EXPENSIVE way to perform this task.
With all that said,
What you need to do is check your fuel system and your ignition system when the engine dies. If the engine does not start right back up after stalling, it makes things a little easier because some "manual" testing can be used to verify a few things.
Check to see if there is spark at the spark plugs. Check to see if there is (A) fuel pressure at the fuel rails and (B) injector pulse at the injectors. This will tell you if it is a fuel "delivery" problem (fuel pump, relay, fuel filter, etc.) or a fuel "injection" problem (computer inputs, injectors, injector circuits, etc.) or if the ignition system is malfunctioning (coils, wires, computer, electrical connectors, security system, etc.).
From the sysmptoms you are describing, it sounds to me like if you were to actually check these things like they SHOULD be checked, you will most likely find that the fuel pressure is within specifications and that you have no injector pulse or spark at the spark plugs.
If this is what you find, then the "most likely" cause of your problem would be a failed crankshaft position sensor, because this will affect BOTH the spark and the injector pulse at the same time.
Proper diagnosis recommended.
on Aug 13, 2018