Problems at start up

96 tacoma 2.4. Having trouble at startup with the tach needle bouncing between 650rpm and 200rpm and then the engine will die. If I start it and give it gas it will run but when I come to a stop sign it will die again. Once I get going and keep the rpms up for a bit then it wont die anymore and idles normally.
The IAC is clean, I just cleaned the MAF, the intake temp sensor is new, the coolant temp sensor is new, the valve lash/pucks were recently done, cap, rotor, plugs and wires are all new. I even turned the key 3 or 4 times before start up to prime the fuel system and it still did it. Any thoughts?

 

when was the last time you replaced the fuel filter?

 

Throttle body cleaned? Any codes? Just at startup - does it get better once warmed up, or can you not get to "warmed up"?

 

Cleaned the throttle body and entire top end when it was off for the valve puck job. Changed the fuel filter about a month ago and there are no CEL codes. Once the temp needle comes off of the C then it runs fine.

 

Anybody? Im almost thinking o2 sensor related but there is no code at all

 

just though about it but it could be a cracked vacuum line that's split and the engine vibration changes the seal so the vacuum changes making the engines rpm change

check all your vaccum lines and the big one to the steering bellows

 

Steering bellows?

 

sorry, meant power brake bellows, big round can on firewall

 

If it was a vacuum leak then wouldnt it happen all the time and not just when the engine was cold?