Dies When Off the Throttle

I've searched and searched and searched but still cannot find a definitive answer. I have a 96.5 Tacoma with the 3.4 and manual. I recently put in a rebuilt 3.4 after it was discovered that the compression was way low in the middle cylinders. In addition there is a new TPS, a cleaned out IAC and some other things I will list.

The problem is that when it is cold and I let off the throttle the engine stutters bad, sometimes dying when I get off the highway. The problem (I assume to be poor fuel delivery) only seems to occur when there is deceleration or a let up on the gas pedal and when the outside temp is cold, below 50 F.

I recently did a fuel pump after first putting in a faulty replacement fuel pump. The wires looked fine and there didn't appear to be any kinks in the line. The faulty pump wouldn't start after a long, hot soak- about 1/2 hour after the engine had warmed up. The new pump has fixed these issues.
While this was happening I 'tried' a new MAF before I put in the new fuel pump. That MAF didn't make a difference so I returned it- this was 2 months ago so I can't rule out the MAF but I doubt that I can 'try' one out again.

Was thinking inertia switch but there isn't one.

Any ideas out there?

 

Idle Air Control under the throttle body

 

Check engine Coolant temp sensor. That is what manages IAC valve. Your second bet could be vacuum leak which adds air to system behind MAF.

 

Fireturk: I cleaned the IAC spotless and the solenoid had no issue spinning; but that doesn't necessarily rule out the solenoid, does it? Is there a way to test the solenoid other than banging on it when it is cold?

I forgot to mention that I did put a new coolant temp sensor in the rebuilt engine given its pain-in-the-ass location under the fuel rail. I know the ECU works with the MAF and coolant temp sensor so I am back to the IAC solenoid or MAF.

BlueT: would a vacuum leak be sensitive to a low ambient temperature?

this only happens when it is cold....anyone know if a faulty open circuit (fuel pump) relay brings about throttle-off stuttering during cold temps?