Hesitation/misfiring...NEED HELP!!

[mbonder]

I tried to search for threads regarding the question I am about to pose, but this seems to be a fairly rare one (I hope not though).

Most threads i pulled up talk about hesitation or misfiring as the engine is warming up, this is only part of my problem. My engine will hesitate like crazy when it is warming up to the middle temp line and then it gets marginally better. It will still hesitate(just not as much) when it is fully warmed up.

I have not opened the hood yet, so i would like to get some opinions on what this could be before i go searching(at least to have some ideas instead of just running around aimlessly).

So far I figure it could be one of three things:
1. Fuel system/fuel delivery-such as dying fuel pump, clogged injectors, dying fpr
2. Electrical system-such as bad plugs(although they are fairly new), rotor, distributor cap, wires
3. Vaccuum leaks-in any of the rubber sections before the throttle body.

Any insite from people who have had/solved this problem would be greatly appreciated.

Matt

[UNHCLL]

define hesitation

like floor it and nothing for 5 seconds
or like give it a little gas, and get a surge 1/2 second later

[mbonder]

This hesitation has nothing to do with putting the engine under full load. This is normal accelleration, between 1/2 and 3/4 throttle most of the time.

The best I can describe it is I will start from a standstill and start to accellerate. Sometimes it will start fine and then start to hesitate like there is only combustion in half the cylinders, so the car will start to shake(best i can describe it). Sometimes it will immediately have those symptoms upon accelleration.

The toughest thing is that it doesn't occur at a set rpm, this can happen anywhere from 1500-4000, which has got me very frustrated and concerned for my car.

I hope that describes things in better detail.

matt

[Digitalwave]

This is tough but I am going to go out on a limb and say its the fuel system. Have you replaced your fuel filter any time recently?