project793

iTrader: (2)

So the car runs great when its warm, perfect idle, never dies, etc. But when its cold, or come to think of it, whenever I start it up, the idle is really low, causing the car to die. Now im starting to think that its not the water temp settings, ive played around with the water temp setting but it seems to have no effect at all. I have to keep the revs up myself for about 15-20 seconds on a cold start, and on a warm start, I just have to blip the thorttle a little to raise the revs, and then it idles fine at about 1000. Any ideas?

muibubbles

iTrader: (36)

idk if this is any help but when i drive around then sometimes when i stop my rpms drop... car sounds like its struggling to die... turns out my volts drop down to the low 13's .... maybe check your volts?

arghx

iTrader: (3)

have you removed your ISC and/or modified the throttlebody in any way? The water temp correction table controls cold start fuel. The ISC and the thermowax/fast idle cam control cold start air, if that makes sense. The ISC and throttlebody dashpot are designed to reduce stalling on decel. All these systems are outlined in the factory service manual.

project793

iTrader: (2)

yea i did remove the isc with the blockoff kit.
Edit: did more searching, looks like it is the ISC, I would prefer to just keep it off, as I like the way it idles when warm. Would adjusting any idle screws help me out with the cold idle? Thanks

cewrx7r1

iTrader: (2)

Without an ISC, you have to hot tune idle: AFRs, Timing, and Air Flow for best idle and at a higher rpm as to not die when full electrical and AC load are on.

Thus your idle will be over 1000 rpm. Then when you cold start it, hold it at 1500 rpm for about 30 seconds and it should idle on its own.

arghx

iTrader: (3)

The TB coolant hose and fast idle cam will hold the throttle plates open during cold idle. On my FC I retained that system and removed the ISC. Since the basic throttlebody design is the same between the two generations, you could install a stock TB and regain that functionality if it bothers you enough. Mazda put those systems there for a reason.

Personally, keeping my foot on the gas annoyed the crap out of me, especially if I just wanted to start the car up and drive away immediately. So I put the TB back to stock. The coolant hose is annoying, but I don't think it makes enough of a performance difference to be worth sacrificing that driveability.

project793

iTrader: (2)

Thanks for the advice guys! Im going to try and put the ISC back on..