2001 Grand Am SE hard start

[00twisters]

2001 Grand Am SE, 2.4L Quad4, 118K miles

Problem began last summer and has been rearing its ugly head again lately. The car will crank and crank, but will not start. Most days it does start, but only after a few cranks. This problem seems to arise when the humidity goes up. Some other symptoms I've noticed:

1. Loss of power. It almost seems like a cylinder is out since the engine works harder than it used to (as in before last summer).
2. Gas mileage is poor.
3. Sometimes idles rough at a stoplight.

What I've had done:

1. Fuel pump replaced at 117K;
2. Complete fuel system/injector service;
3. Complete tune-up (plugs replaced, etc.);
4. Routine maintenance

What I think the problem may be:

1. Ignition module problem, either the coil itself or the housing;
2. Vaccuum leak.

Any insight would be greatly appreciated!

[sampsonite]

I seem to be having a similar problem with the same car, similar milage (105k). The most noticeable thing for me has been the rough idling. Out of curiosity, what brand of spark plug are you using? For me, the described symptoms coincided with a recent spark plug change (used bosch platinum plugs) so I was thinking maybe they aren't very compatible with this car.

[00twisters]

I have the same plugs, the Bosch Platinum. This problem didn't coincide with the change, though, but I noticed this morning that the idle was a little more rough than usual.

For me, the most noticeable change is the loss of power, which is why I think a cylinder is out. I've taken this car to 4 different shops and no one can figure out what the problem is.

Any idea on how much a shop would charge for the ignition coil replacement?

[sampsonite]

I have no idea what the cost would be for that one....I think I'm going to try different plugs first. Do you remember what brand the stock ones were? I'm thinking AC Delco........

[00twisters]

Yeah, I believe the original plugs were AC Delco. Hopefully the change helps you out!

[jarbag]

cheap checks - dirty throttle body ports/valves or plugged fuel filter