I was driving along today, when my RPMs dropped all of a sudden and the engine shut off. The engine does start, but after about half a second it dies off again, slowely muttering and dieing. What do you guys think it is? MAF or fuel pump?

 

Sure you aren't out of gas?

I've had one fuel pump go out and it pretty much mimicked what your car did. I was driving along and all of a sudden had no more power. If I gave my car any throttle it would die immediately. It would start and idle fine but if I stepped on the gas it would bog hard and die whether it was in gear or in neutral.

If the MAF is bad, the car will run okay up to 2500 rpm or so but won't go past that.

 

I had gas, like half tank. I think it is the fuel pump tho. I also drove on low gas once, it did the same, do you think the injectors might have gotten messed up?

 

I would think fuel pump or one really dirt fuel filter, as Scott has said most guys with a MAF problem report the car starts and runs but will not exceed 2500 rpm. Running the car down till the fuel lamp lights up can cause your pump to deliver the real crud that settles in the bottom of the tank. So as I said it could be the pump or the fuel filter/strainer is all clog up and not allowing any fuel to get through.

 

I'm going to change the fuel filter and see what happens. I swear I saw someone selling one yesterday.. weird.

 

Do you hear pump working when you turn key to ON?

 

How does the pump sounds like?

 

In my case: it makes humming noise when I turn key to ON first in the morning following cut- off thump(?) and then- nothing. Please make sure you don't turn the key all the way to START as you won't hear this at all.

 

I was just checking the car and it started up, I drove it but it would'nt pass 2000rpm. Looks like a MAF problem but the wierd thing is, before it would'nt turn on at all. This just made me even more confused... since i drove it for 10 minutes, the fuel pump must be working.

 

I know how it sounds but could you please be less ambiguous when you describe a problem? This way you'd have better chance to get attention of more experienced people here. I couldn't make anything out of your statement above. Were your lights not coming up when you turned key to ON? Was starter not cranking? Was the engine not starting? Did you try to perform common fuel pump test I mentioned? Did your check that the car is electrically sound: battery voltage is close to 14.4V with engine at 1k rpm, ground wires are clean and their bolts are tight?

Don't get me wrong- you don't have to do any of the above - it's your car.

 

The starter cranks normally, battery's alright too. Basically the engine would turn on(like usual) and after idling about 800-900rpm for a second or two, it would drop to 500, then 300 then off. Basically feels like the car has no gas in the tank. Also this problem started while I was driving, the car basically turned off on the road.

The interesting thing is that when I went back to the car about 5 hours later, it turned on and idled perfectly, but I couldn't get passed 2k rpm (much like the MAF problem.)

The first problem sounds like the fuel filter but the second one sounds like MAF. But what are the chances of them BOTH going bad at the same time.

 

If it was my car I'd clear the codes, started the engine and if ECU still complained about MAF I'd replace it. Then I'd worry about fuel pump issue if it was still present.

Inability to pass 2k rpm indicates that car is in the 'limp' mode. MAF is the only reason I'm aware of to make it happen but I won't be surprised if some other problems can put ECU into this mode. Fuel pump failure is not one of them though.

Please check/clean MAF connector before replacement, just in case. Cleaning MAF itself won't help in your situation, don't bother.

 

Thanks alot, I'm going to get the codes tomorrow and report back.