cold engine problem

[foutong]

Hey guys, so I have the 3vzfe running for about three months and in the past few weeks when the engine isn't fully warmed up and when I give it a little gas the rev actually drops a bit then goes up. I've welded the iac so it would never fully close. After the car warms up this isn't a problem. I remember seeing someone else had this problem but I cant seem to find the thread. Any ideas on what I should start checking first?

[stevehall]

I had similar trouble with a faulty temp sensor, also sometimes trouble starting, highlighted in blue. It's a different sensor to one that drives the clocks, so the needle can be steady but ecu is all confused about the temperature.
http://www.twobrutal.co.uk/forum/images/recovered/2009/09/10.jpg

[foutong]

Thanks I probably wont get a chance to get into it until spring break. I need to get into there and clean up the wiring anyways.

[foutong]

So I replaced the sensor but it still does it. it looks like I had a coolant leak that I took care of but it still happens. I've noticed that the lights dim and the voltage drops too when it is warming up. I'm wondering if there was something that I could of messed up in the wiring to effect the open loop?