Engine stalling and very slow acceleration

[Ross410]

In the middle of a 2 hour drive this past weekend, my 2004 4.0 explorer's check engine started flashing. The code is 0302, which is a cylinder misfire I believe. As soon as this started flashing I noticed my acceleration seemed a little week ( i was already doing about 60 mph). When I got the next red light the engine would start shaking and nearly stalling, then by the time I got home it stalled out at the traffic light near my house.

I replaced the fuel filter after seeing the sticky on the boards here (awesome btw) but that did not fix the problem at all. Today on the way to work , it was very shaky and stalled once I got close to work. It stalled out several times once I placed it in drive again before I could get it going. Also once I do get it going, the acceleration is pretty weak the entire time. Ideas?

 

[Ross410]

Took it to a shop and they replaced the mass air flow sensor, the plugs and the cat converter and it still isnt fixed. Cant afford to have them do anything else to it. Anyone have any idea what it could be?

 

[matt0248]

P302 is a cylinder #2 misfire. Could be a bad plug, wire, coil pack, fuel injector, leaking intake manifold gasket, damaged vacuum hoses. I would demand you $$ back. A MAF will not set a single cylinder misfire code, just as well a plugged converter will not set a single misfore code. These things would set multiple codes, and have different driveability symptoms.

You also could have a mechanical problem such as a broken valve spring. I would start with a compresson test on the cylinder is misfiring to make sure the mechanical side is in order before looking into the fuel and ignition side of things.

The reason you feel a severe lack of power is the throttle by wire system going into a limp-in-mode. It will only allow the throttle to be opened a certain amount to try to protect the engine.

 

[Ross410]

Just got a call from the shop and they tell me that cylinder 2 has no compression at all and recommends a new engine. I asked if that was my only option and he said new engine or get it rebuilt. Does that sound about right?

 

[matt0248]

It really depends on why it has no compression. Did the valve sprin break and the valve drop and got hit by the piston, which would damage the piston and vlave. This would require the engine to be removed and repairs. Not cheap. Is it becuase of a blown head gasket? Again not cheap. To really know they would need remove the valce cover and spark plugs and do a visual inspection. But either way it seems as you are up a creek. Maybe you could find a low mile used engine somewhere. Sorry 'bot the bad news.