more air w/o forced induction

[MR 325]

Facepalm.

[Earendil]

Damn, just remembered I left the thermostat out....might just be runnin to rich cuz of that

Well the engine would never know its warmed up so it would be in open loop constantly.

it's more that the engine will never warm up, so it'll be stuck in warmup mode which makes it run richer.

Facepalm.

I sort of assumed, when I read it the first time, that he left the mechanical coolant thermostat out. Are you guys suggesting he didn't put a Coolant temp switch in?

Without a thermostat, the engine would certainly run quite cold, but I don't think that'll trigger any sort of open look mode like removing the coolant sensor would :)

[AndrewBird]

^^^ What he said. Removing the thermostat will likely just make the car slow to warm up, but it should reach normal operating temps, or at least close. Close enough to not keep the engine in warm-up mode.

I would bet on a bad o2 sensor.

[nando]

no, it won't reach operating temp without a thermostat. maybe if you live in the desert.

as long as the engine isn't running at operating temp, it will be stuck in permanent warmup mode, which makes it run rich.

[MR 325]

Exactly. My brother's 325iS had no thermostat when he bought it. The car would take an hour to almost hit half temp. It's not the 1960's anymore, people need to stop thinking removing a thermostat does any good. They are $10!

[BavBeater85]

exactly how mine is....when I did the timing belt and waterpump i couldnt get the air out of the system so I took the thermostat out and bam...but now it takes forever to warm up and runs like crap and stutters until its warm, which is a while

[BavBeater85]

I just completed a motorswap not to long ago and have been workin the bugs out....so all the sensors are new including both coolant temps and the o2