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Discussion Starter #1 (Edited)
Hey there, I'm new to the "wonderful" world of Toyotas. Most of my experience is with pre 75 American cars so I need a bit of help with it.

The car is a 83 Celica GR with a 22re and 5 speed with around 145k miles.

The issue im experiencing is what I think is a lean condition once the car is at operating temperature. While the car is cold/ just warming up it runs great and has pleanty of power but slowly as it does warm it starts to backfire and surge.
It will first start where anything above 4500RPM it has no power and starts to buck, then as it warms it lowers the RPM range where it has no power going all the way down to 800RPM.
I have noticed if I turn the car off then back on again it will raise the range that it does have power.
I've replaced the obvious things that might cause this, (Coil, Plugs, Cap, Rotor, Fuel Pump,O2) Timing has no effect on it. I don't think its a bad EGR, I disconnected the vacuum lines to it and it had no effect. Unplugging the TPS does nothing.
The only things I have left to check is the ECM, Ignitor, Injectors, and Air Flow sensor. While I haven't changed the fuel filter(waiting on part) I don't see it being the cause as the in pump cone filter was clean.

So if anyone can think of what I might have missed let me know cause this thing is driving me nuts.
 

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Sounds like a fuel flow problem. Check the fuel pressure probably fuel pump on its last legs.
 

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could be the fuel pump or possible carbon build up on valves or burnt i have seen with same type of issues, cold starts runs once warm engine starts to shake even to point like it misfires. worst cast i saw this was on a 7MGTE
 

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You said you replaced the fuel pump. I would install a fuel pressure gauge at the cold start injector with an adapter to see if the regulator or new pump is any good. Russell 640700 M12 x 1.25 Banjo Bolt 1/8" Fuel Pressure Gauge Take Off.
16314


Add fuel gauge to adapter and record reading with vacuum line to regulator on and off. Would still look at EGR valve system for sticking open, would remove and block off to see if it fixes the lean condition.
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Discussion Starter #5
Checked the EGR and it's fine, moves and holds a vacuum with the hand pump, also cant block it cause of Commiefornia. I have some parts coming to check first, the EFI coolant temp was reading about 20 degrees off and I'm going to swap the ignitor with a GM HEI one. If neither one of those works I'll check the fuel pressure but I'm thinking it's something else since it's Identical after the change.
 

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Discussion Starter #6
Ok here is the full list of everything I have checked/replaced.

EGR Cleaned and is working normally,
AFM working properly except for slightly high resistance on the closed setting,
replaced EFI coolant temp sensor,
new remanufactured injectors,
Ingntor replaced with GM HEI unit,
Coil replaced,
Fuel Filter replaced, original was in fine condition,
Fuel Pump replaced and filter cleaned,
ECM check done by the way the service manual outlines,
O2 Sensor changed,
Throttle body cleaned and TPS to factory specification,
Plenum cleaned along with inlets and EGR passage.
New Spark Plugs and Wires,
New Cap and Rotor,
Timing Set to factory specification,
Trouble codes checked and none show,

The only things left to check that come to mind is the pickup inside the distributor and fuel pressure. I also did a visual inspection inside of the ECM and it all looked ok except for the 100uf 16v capacitor has some corrosion from what I think might be leakage, but don't know if this would be causing the issue.
I did happen to catch the car on video doing it while not driving, here is the video.
 
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