Engine runs fine until shut off then turned back on

[broncoiisvoswap]

Edit > Forgot to add, this is  a 2.3 lima turbo motor I swapped into an 1984 bronco ii (If you didn't read my name), engine came out of a 84 SVO Mustang.

I have an issue where my 2.3 turbo engine starts acting up if I turn it off then back on while at operating temperature.

If I start the engine while cold and drive it until it reaches operating temperature I have no problems, doesn't matter if I drive for 10 minutes or a couple of hours, boost is smooth. Took it offroading for a couple of hours and hammered on it, still ran smoothly.  Makes more power than a BII needs.

Lets say I drive for five minutes and turn off the vehicle before reaching operating temperature, then turn it back on, it will be fine.

If I drive for 20 minutes, lets say across town, turn off the vehicle, go into to the store, come back out and turn the vehicle back on after the engine heat soaks. Then the motor will stumble like the timing is off, it'll make the entire vehicle shake and the idle will surge to 1500-2000 rpm and stay, when I let off the gas pedal while driving there is a huge delay to when the rpm's actually drop, for example, lets say I let off the gas then push in the clutch at 3000 RPM, rather than the rpm's dropping immediately it will sit at 3000 rpm for about a second.


I do want to mention some modifications that I have done to this motor on a stock Thunderbird Turbo ecu.

I removed the stock inter cooler and changed it to a front mounted one.
The hole in the valve cover has been routed to a catch can, and so has the pcv valve.
I am using an SVO Mustang intake WITH A 87 THUNDERBIRD LB2 ECU, my upper intake had a plugged hole in it from the factory, and the Air Charge temp sensor went right in, didn't even have to change the threads.

I am using a throttle position sensor from a Thunderbird turbo Intake on my SVO intake.

SVO Mustang VAM (Pretty sure the Thunderbird turbo uses the exact same one)

The EGR has been deleted, so the Knock sensor has been unplugged.
External Wastegate/T3 Turbo (Thunderbird turbos came with an IHI turbo correct?)

My best guess is that it's the Idle air control valve, but I'm not sure if the Idle air control valve can cause the motor to stumble like that.

[Stinger]

What's a code scan output for fault codes? Report the actual code numbers, not the description.

[broncoiisvoswap]

I will do that... tomorrow.

[perri2300]

Did you ever figure out what was causing this problem? I have had this issue with my build for a while now and I never found out what it was. It prevents me from driving the car because I can't get it tuned in that condition.

[Stinger]

He was using a stock ECU so it's likely unrelated to your issue. You have the ability to datalog the issue and ask for assistance with it in the Microsquirt section.