2G Weird idle

[Dawson159]

so here’s the deal,

Whenever I start my eclipse it idles really bad and almost stalls until about 5-10 minutes later the idle jumps and idles regular. I can’t drive it until the idle spikes so it sucks.
I’ve researched it a bit and it seems that what I need to do is block my FIAV. I found a thread on how to block so should I do that? Is that what’s mostly likely gonna fix it?

The only reason I’m asking is I want to daily drive it and I live in Montana so it gets cold and it makes it hard to cold start but I have another car I can drive if it gets too cold

 

[motomattx]

Just the opposite, you need that fiav if you live in a cold climate.

 

[Dsm panda]

Describe really bad? Low rpm? Sergeing?

 

[Dawson159]

Describe really bad? Low rpm? Sergeing?

IT jumps around at about 200-800 rpms and almost dies until the rpms jump then it sits at a steady 1000 then I can drive it

 

[93AWDDSM]

I have a FIAV bypass. I live in Washington state. It’s 30 degrees and lower now. Car starts fine, idles at 1200-1300 and then settles down to 750+- when at operating temp.

 

[Dsm panda]

If you do decide to do a fiav plate do a bypass not block off or you will have idle issues ask me how i know

 

[Dawson159]

I have a FIAV bypass. I live in Washington state. It’s 30 degrees and lower now. Car starts fine, idles at 1200-1300 and then settles down to 750+- when at operating temp.

Ok I’m going to order a bypass plate instead

O

If you do decide to do a fiav plate do a bypass not block off or you will have idle issues ask me how i know

ok I’ll do the bypass instead

 

[steve]

Doesn't sound like a FIAV problem to me, more like it's not firing on all cylinders for awhile. Is that possible?

 

[Dsm panda]

Have you played with the biss screw without a good reason to? My car did that when i fixed the ecu previous owner just played with it insted of doing it correctly trying to fix a high idle. He left it all the way in so and the car wanted to serge and die.

 

[Dawson159]

Doesn't sound like a FIAV problem to me, more like it's not firing on all cylinders for awhile. Is that possible?

I don’t think so because it idles and drives fine after ~5 minutes

Have you played with the biss screw without a good reason to? My car did that when i fixed the ecu previous owner just played with it insted of doing it correctly trying to fix a high idle. He left it all the way in so and the car wanted to serge and die.

I haven’t messed with it but the previous owner could have is there a way I can check?

 

[steve]

I don’t think so because it idles and drives fine after ~5 minutes

And during those 5 mins or so when it's not idling fine, is it firing on all cylinders or half?

 

[Dawson159]

And during those 5 mins or so when it's not idling fine, is it firing on all cylinders or half?

Now that u say that it does act like a misfire because when I drove it it had no power and won’t get over 2k rpms and wants to die. But how can it suddenly start running fine after 5 minutes?

 

[motomattx]

Now that u say that it does act like a misfire because when I drove it it had no power and won’t get over 2k rpms and wants to die. But how can it suddenly start running fine after 5 minutes?

The spark plug wires could dry out, any number of things.

 

[Dawson159]

The spark plug wires could dry out, any number of things.

I just replaced the wires and the plugs but one of them might be fouled because my car is running rich so I’ll check

 

[motomattx]

Did you buy a good brand? I have seen brand new NGK out of the box cause a misfire that went away upon putting used oem back on the car.

 

[Dawson159]

Did you buy a good brand? I have seen brand new NGK out of the box cause a misfire that went away upon putting used oem back on the car.

They are NGKs but I ran a timing light test and they are all firing correctly. I’m still confused on how that could cause it and suddenly be fine and drivable after 5 minutes.

Could there be something wrong with my coolant temp sensor or something that has to do with that?

 

[motomattx]

Coolant temp sensor usually causes starting issues.

 

[Dawson159]

Coolant temp sensor usually causes starting issues.

Oh ok It starts fine just doesn’t idle well at all until it it spikes then stays where it’s supposed to stay