Celica Forums General Discussion Engine and Performance Celica 2001 loss of power and misfire

Hi everyone, I've recently bought a nice Celica (140hp) year 2001. 100k miles.

I love the car and the price I paid for it was very reasonable. I'm glad I found this forum which I have searched for my specific problem, but I think the topic was on the 190hp version.

Car will start fine perfect every time, runs good in general BUT: when I accelerate with any enthusiasm the car often misfires, and is momentarily down on power.

When I rev quick on idle out of gear it stumbles climbing the revs.

It's almost like its not getting enough fuel or something.

Sometimes once warm the car idles a little rough with more vibration than I would expect. Other times its smooth and quiet.

I haven't pulled the codes yet, I inconviniently lost my OBD reader (i'll be getting another soon)

I've cleaned the MAF, looking to give it a full service/tune up

Is there anything obvious I could rule out (common issue culprits) ?

Thanks for having me!

Kind regards

Pattoj

Hey, welcome!

Congrats on your recent purchase. Sorry to hear about your troubles. A misfire under load is no fun to solve, but it doesn't have to be too hard if we apply logic and think carefully. First, I would suggest that you read through a guide I wrote a little while back on solving misfires on these cars:

https://celicahobby.com/forums/ubbthreads.php/topics/455483/ultimate-misfire-guide.html

After going through that, try to determine wether the misfire is a result of running lean or rich and perhaps why it only happens under load. Pull the codes and report back and I'll see if I have any more I can add.

-Connor

Thanks for your reply Connor2002gt, I'm kind of considering buying new iridium plugs anyway as I bought the car at 101k miles and understand they usually need replacing at this kind of milage.

I was given an air filter with the purchase so I'll start with that.

I'll have to buy another code reader so I can pull the codes,

Thanks again!

Hi again folks, I'm back from doing some work on my car in this miserable weather..

P0300 and P0301 were my codes, cylinder 1 once I opened it up had a small amount of oil in the chamber where the coil pack sits. It was pretty dirty, I sucked out the oil, changed all the plugs and swapped out coil 1 to coil 3 (and gave everything a good clean) I'd imagine I'll probably get misfires again if there's oil in the area around the spark plug, what do you guys think?

It's running fine for now but I noticed the problems begin once warmed up

A little oil in the plug chamber is normal after 100K miles. It's caused by a leaky valve cover gasket. It's not a big deal and should not cause misfiring or affect the engine's performance.

Was there any oil on the firing tips of any of the old plug? If the plugs are wet, it would cause misfiring and there would be reason for concern.

The misfiring may also be caused by bad ignition coil. Swapping them around is a good way to find out if the misfiring moves with the coil or stay at the specific cylinder.

Hi and thanks everyone for your help.

I should have told you I fixed it and it was the spark plugs!

It now runs great, I've taken out the butterfly and made a stainless steel intake duct through the center intake in the bumper. I've also put new headlights in and put some used coilovers on it. Looks great now!