Running rough then better?

[wernettejr]

Alright guys I am stumped.
My Corolla wagon is running rough. In the morning my son drives it to school, about 10 miles. It has been acting really bad for him. Spitting and sputtering and no get up. I checked the engine codes and it said O2 sensor and MAP sensor. So I changed those out and reset the computer. Now she runs noticeable better but still is not right. It has alot more power but still sounds like maybe something is missing. I have been dropping the boy off to school and driving the car to work after. Now once I am almost to work she starts running like a top. Im not sure what it could be. Is there something that could be going bad that needs to really warm up before it starts working? My next thought is maybe the distributor is cracked and moisture is getting in there and once it dries out it starts sparing correctly. Not real sure. Any help would be great.

[90 GP]

Get a spray bottle filled with water and when it's dark start it and try misting the cap and wires to see if you can see any visible arcing going on. Check for vac line leaks too.

[wernettejr]

OK I've got an update.
I have not had a chance to check the vac lines yet. We are having a snow storm and I don't have a garage.
But I did notice that since I have made the first post the car has not started running any better. Always running terrible but never actually dies. Sounds like it might. I also have noticed that the temp gauge is not going up to about half way like it used to. It barely hits a quarter the way up the gauge. So after driving it for an hour and a half I popped the hood to check the overflow and it had in it. For the heck of it I put my hand on the radiator cap and it was cold! I would have thought for sure that after running that long it would be scolding hot. I was even able to open it up which I should not be able to do with out ending up in the burn unit.
The radiator was low so I topped it off. So now I am thinking I have a stuck thermostat but I am not sure if this would have anything to do with the main problem. Any ideas?

[rdyzz]

if the t-stat is stuck open your engine would never get into operating temps, especially in winter. if you havent done an ignition tune up yet i would, new plugs, wires, cap and rotor would fix any lag in power if its ignition related which it sounds like it is. if your spark plug insulation is old it could arc to anything metal making it feel like your running on 3 cylinders only.

if you get a new thermostat get a toyota one, dont go aftermarket, trust me theres a difference in the quality. any ignition stuff feel free to go to aftermarket oem. btw im willing to bet its ignition related.

if its not your thermostat, and your losing coolant, losing power...... worst case, is a blown head gasket. for a blown head gasket, you can do a coolant pressure test. theres a tool for it, when doing the test it should hold pressure, if its not, its very likely a blow headgasket also.

[wernettejr]

Right on! New Plug wires and rotor and she is running like a rapped ape. Still need to swap thermostat, but we are on the way!