Car idling to low

[89325iturbo]

My car just idles to low. It idles at around 650-700 rpms. Which would normally probably be fine. But I have a lightweight flywheel and a trm chip for it. So the rpms should be closer to 1000-1200.
The odd thing is it did the first few times I started it, then it just started to idle lower.

[matt]

I can swap it out for you. PM me. :)

Don't try to change it yourself, you will just confuse the computer.

[Adrian_Visser]

Is it true that the idle is set to 1000rpm for a LW flywheel on the TRM chips?

[matt]

Stock is 650, lightweight flywheel is 850.

[e30s50dan]

Yep. Mine is around 900 rpms perfect thx again Matt

[Adrian_Visser]

Stock is 650, lightweight flywheel is 850.

I see, that is about what my idle sits at.

Is it normal for your revs to drop off to like 500rpms and bounce back up again when you let off at higher rpms with a LW flywheel? I have an 11lb JBR flywheel btw.

I'm sorta new to lightweight flywheels lol.

I also have underdrive pullies which lighten up the rotating mass a bit but I don't know if they could affect inertia like the flywheel does.

[Gnarles]

I see, that is about what my idle sits at.

Is it normal for your revs to drop off to like 500rpms and bounce back up again when you let off at higher rpms with a LW flywheel? I have an 11lb JBR flywheel btw.

I'm sorta new to lightweight flywheels lol.

I also have underdrive pullies which lighten up the rotating mass a bit but I don't know if they could affect inertia like the flywheel does.

Mine does the same thing. When I rev in neutral, the idle stops perfectly at ~850rpm, but if I take it out of gear at higher RPM"s it drops down to around 500 and then bounce back up and settle at 850.

I have a lightened m20 flywheel, ~12lb, OBD1 S52 with TRM chip.

[Gnarles]

double post

[7pilot]

My car just idles to low. It idles at around 650-700 rpms. Which would normally probably be fine. But I have a lightweight flywheel and a trm chip for it. So the rpms should be closer to 1000-1200.
The odd thing is it did the first few times I started it, then it just started to idle lower.

The ecu is controlling idle via ICV.
TRM chip with raised idle option.

m

[89325iturbo]

I just don't her it though. The idle will be steady for 10 minutes or so. Then the idle will start to drop and it will die now.
It seems like when it comes up to temp is when things change.
So I thought of things that change at tempature. I unplugged the o2 and I don't get a check engine light anymore. But would a bad o2 cause a bad idle? And should it be able to run good enough without an o2?

[Adrian_Visser]

A bad O2 can cause a bad idle on these engines. I am surprised that you don't get a CEL when you unplug the O2 are you sure about that?

[89325iturbo]

Yeah the cel goes away when i unplug the o2

[89325iturbo]

Any ideas guys?? Just want to figure this out. I've tried different icv's temp sensors and u2 sensor. Only to still have start running badly after running fine for about 10 minutes.

[Adrian_Visser]

Man I am kind of confused as to why the CEL goes away when you unplug it, seems to defy logic to me, something ain't right there that's for sure. Check for vacuum leaks?

[89325iturbo]

Still no progress couldn't find any vacuum leaks. What else could change after a little bit or coming up to temp. If the cel goes away when unplugging the o2 it seems like it would have to be based around that or air fuel ratio changing when it gets warmer??