Timing is correct. Spark is good, compression is on specs. Has new 02 sensor, new tps sensor. New gas pump and gas filter. Change all the fuel injectors rings and gas filter. New distributor cap as well. What can it be?
I would also suggest testing the throttle position sensor. Test it back at the ECU to include all the cables and connectors. A disconnected TPS can cause a similar problem.
Good luck
My suggestion is to make sure it's running on all 4 cylinders too. Pull each plug wire from the spark plug one by one. If you pull a wire and it doesn't run rougher then you have a cylinder that's not firing.
Hi Antonio,
Just watched the video.
My guess is that it could be any of: bad gas, fouled plug/s, not running on all four cylinders, or vacuum leak.
I think that any of the above can make it run rough like that.
What does the exhaust smell like? any raw/unburnt fuel smell to it?
I once had spark plugs that looked great by visual inspection but my mr2 would miss and stumble above 4000 rpm. Replacing the plugs fixed the problem (after replacing the fuel filter didn't help).
That it doesn't go past 3000 rpm makes me wonder if there is a cylinder not firing.
Come to think of it, a couple more things come to mind: a bad ecu, and timing belt jumping a tooth... hopefully neither of these.
Luckily, testing some of these is relatively easy (filling new fuel, pulling plug wires while running, replacing with new spark plugs). Hopefully, it's nothing more serious than these.
Good luck.
First of thank you all so much for your response they have been super helpful I was so frustrating and thankfully with all your help and suggestions the problem is solve., this was do to out of order spark plug connection. Now the only thing left to correct is: the fume gas smell that comes from the exhaust manifold. I want to replace it new. You guys have any suggestions yo find one?
I was window shopping on Ebay last week and found some manifolds for mk1 MR2 for sale. There were some new ones (aftermarket headers) and some old ones (used non-sc manifolds). I don't know if Toyota still sells these.. maybe they do, but likely $$ expensive.
But I doubt that the gas fume smell is from the exhaust manifold itself. Perhaps some of the unburnt fuel is still lingering from when the firing order was wrong. But that will correct itself as you run the car over time. I'm guessing it's still running rich for some reason which is why you're smelling fuel in the exhaust.
Side thought -- Maybe it's your vapor canister that's old/saturated and needs replacement. I've read that others with this issue generally smell the raw fuel smell around their car besides in the cabin.
Edit (sorry - meant for OP)
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