Over the last couple of weeks when I cold start my car sometimes it gets this really erratic idle where it revs up to 1500 and bogs down to 500 and does this several times until it levels out. Also when my car is cold, the engine noises is much louder and it vibrates a bit almost like a misfire. However, when I rev the engine once, it goes away. I just did plugs and wires.
Here is a video of the start up:

However, after a 15 minute drive, the idle sounds normal:

Other things. I checked fuel injectors after a 45 minute drive and all eight were at 16 ohms. I did do a cold fuel pressure test and with just the fuel pump on pressure dropped from just over 40 to about 35 after 5 minutes.

Fuel pump is a Walbro and is about 8 years old. Sending Unit was also replaced at the same time. The Walbro still primes when I turn the key to ON. Fuel Pressure regulator is about 4 years old. Car has no problems starting and usually starts on the first turn of the key.

Any idea of what this could be? I just replaced every vacuum line.

 

16 volts at injectors?

 

Yeah at injectors.

I meant to type 16 ohms.

 

How olds the cts have you datalogged ?

 

It's been a few months since I did a TurnerPro scan. I was thinking of doing a new one tomorrow. I know my last major problem was blown header gaskets and bad plugs/wires. That was from that scan.

 

New datalog could be good here. Also I'm hearing a ticking / puffing on the warm idle, sure you don't still have exhaust leaks?

 

I'll check on the header bolts. I have brand new bolts and they could have just loosened up after a few hundred miles.