Gen 7 Misfire Problems

[kellboss]

Hi there I have a gen 7 celica on a 52 plate (uk) I bought the car no realising the engine was pooped, the piston rings had gone. But about 60 miles before having the engine replaced it started to idle really rough and very low (when warm), I just thought it was a one off and kind of ignored it at the time, then about 10 later the engine management light came on, whilst I was driving but I assumed that it was something to do with the worn out engine, and thought I would limp along as I was having the engine replaced and thought it would fix the problem.

I had the engine replaced but the problem was still there, and by this time i had noticed that when the engine was cold it was also surging and revving too high, about the 2500 rpm, then once it was warm it was idling at 500 and below but not actually stalling. I have done the following to the car to try and fix the problem:

Replaced the coils

replaced the spark plugs

replaced the fuel injectors

replaced the maf air flow system

replaced the throttle body

replaced the tps

replaced the ocv valve

cleaned all the other sensors

checked and cleaned the air filter

checked the fuel pressure

had the lamda sensor checked

replaced the ecu unit

checked for a vacuum leak with carb cleaner around the inlet manifold

Had a compression test

had the head gasket checked

Diagnostics plug in, countless times

I am now out of ideas and money, all the diagnostics keep coming back with is misfire on cylinders 1 and 3, you can hear it sucking in air around the inlet manifold/throttle body area.

It still starts and drives ok at higher speeds, but very jerky and makes a very uncomfortable drive at lower speeds. I can't tell if the power is reduced or not as I'm not sure how powerful it should feel. It uses more fuel than it should I think as I had a gen 6 celica 2.0 16v, which was only doing 24mpg and these gen 7 are suppossed to be better but I think the fuel consumption is worse and quite erratic.However I am not sure whether this is because I am revving it more to stop it stalling or it is just using more. When driving at higher speeds the revvs are where they should be on the clock.

I feel the car is getting worse as it has started to stall when I have to stop in traffic etc. I have an inlet gasket that I was going to replace but I'm not sure that this is the problem. Please can anyone give me any ideas or experienced anything like this before? I don't have anymore money to spend on trying to find out the problem as the mechanics it has been to are all out of ideas..... Thank you in advance