No Engine Start After Rebuild

Recently had my engine top and bottom end done after a spun a rod bearing. Also had to replace torque converter and transmission oil pump after I incorrectly installed the motor the first time. After getting anything back together into the car, I can not get it to correctly start. It'll turn over, rev up a little, and immediately cut off.

- Correct fuel pressure.
- Injectors read the correct resistance
- There's a noticeable difference if I unplug the injectors, it won't turn over at all if I unplug them. So I know they are at least doing something.
- Car fires up and runs normal if I put gas down the intake. So I have spark.
- If I apply a little throttle, it will start up and run longer. But as soon as I take my foot off, it cuts off.
- Security light is not blinking, so I don't think it's the immobilizer.
- I did have a P2101 (Throttle actuator circuit range/performance) at one point. It has not come back on, yet.
- The throttle plate *appears* to be opening and closing fine.
- Everything on the wiring harness *appears* connected.

I was thinking of testing for vacuum pressure, but the PCV is under the intake on this thing. The brake boost line won't fit my vacuum tester either. But if it was a vacuum problem, I would have thought it would have thrown a related code by now.

Any suggestions on how I can narrow the issue down?

2006 Mazda 3 2.3L

Is all the ducting from the MAF to the throttle body hooked up?

Thanks for sharing good info.

Turned out the PVC valve was not attached to the hose coming from the intake manifold. It is hidden behind the intake manifold on this engine. I must have forgotten to attach it when I put the manifold on. I assume I was getting no codes because the sensor for vacuum pressure hadn't had time to come up yet.

I don't think that car has a MAP(vacuum) sensor. Most Ford/Mazda products are MAF only.

Glad to hear you got it figured out.