Hesitation problems, Im guessing its a sensor of some sort Options

[6gsillyca]

I currently have a JDM 93 3sgte motor/ECU swapped into my celica. When it is cold out the car has some bad hesitation problems when first started. Usually the colder the engine is, the worse the hesitation.

Before when it was cold out it would start, but not run properly for the first few minutes. It had a lot of hesitation. When you applied the throttle (either in gear or in neutral/no load) the rpm's would rise, but be very choppy.

Then, went to pick her up from the shop today, and she had been sitting outside for about 6 hours, it fired up fine, but then bogged down and died (very sputtery). Then it would crank but not start up. We pushed it back into the shop to try and warm it up a bit, and kept trying to start it. Finally it started up again, but again was very boggy (it sounded like a large v8 car, low throaty duh-duh-duh-duh-duh). We held it a WOT just to keep it running. It spewed out massive amount of smoke until it started to warm up, then it began to idle normally (and w/o needing to keep the throttle open)


Any idea's?

[GMan]

It could be the cold start time switch, or the water sensor. Most likely.

It took me a while to track down My cold start problems.
If it starts, then runs like crap and Hunts, could be the Idle Speed Controller.
The ISC is under the throttle body, basically a magnetic cylinder that gets carbon build up on it.
The the ECU cannot open and close it easily, so it Hunts wildly. Easy to clean and reassemble.

Could be as simple as the plugs fouling when the CSI dumps fuel ?
Using a colder range plug or anything exotic such as Iridiums ? They foul pretty easily.
Are they relatively new ? I just throw in cheap copper and change them regularly.
It took a while to figure out, but I think I have my cold start problem solved solved now.

Regards;