Eric L.

Ok, we all know that 4th/5th gens here have had starting problems. Mainly, the engine cranks and cranks (i.e. battery is ok) but does not turn over. It has happened to me like half a dozen times over three years. What I've noticed is that it's like there isn't enough gas getting in to fire the engine up.

So I was thinking, sometimes stepping on the gas a little doesn't fix the difficult starting, so how about this...maybe it's an ECU problem. The ECU does change fuel mixture settings depending whether it's a warm or cold start. I've found that my starting problems always occur when the car has been parked for a couple hours. It has never had trouble starting when its cold (like in the morning). So maybe, whichever temp sensor tells the ECU to choose from rich (cold start) mixture or lean (warm start) mixture is giving a faulty reading. Or better yet, maybe the place where the sensor is located is in a particular warm part of the engine, so while the rest of the engine is cold, the sensor still records a high coolant temp. Hence, when the car has been parked a few hours, and the engine temp is essentially "cold", the sensor detects "warm" and when you try to start your car, the ECU doesn't send a rich enough fuel mixture to turn the engine over.

What do you think? It's only a theory, but I refuse to believe that problems with the engine not turning over can be the result of a bad starter, since each time I've had that problem the starter sounded just fine.

Jeff92se

iTrader: (82)

I agree, the only purpose of the starter is to turn the engine over. NOT TO START THE CAR. Funny, when my 3-gen has been sitting overnight and it's colder than usual, it starts up fast and on a really high rpm for 1-2 seconds and settles into a normal cold mode.

I agree w/ you. If you car has been started and then sat for a few hours, it's not really warm and not totally cold. The heads could be cold enough to require a cold start mode mixture but the ambient and engine temp sensors could be telling the ecu otherwise.

It's a glitch in the Matrix, better get the hell outa there next time.

Rit

iTrader: (3)

are having starting problems feedback their data on when the problems occur. If we can support this hypothesis, can we feed it back to the Nissan design engineers, and maybe they can develop an inexpensive fix for the problem. It seems pretty embarassing to have a $30K car with starting problems, when most cars half it's price are able to start 100% of the time.

Let's work on this problem.

Eric L.

The funny thing is that the opposite happens to my friend's 99 Civic. Whenever it's not been driven for couple days, it always stalls when first started. Hehehe...