ISC Valve Rebuild (1 Viewer)

[brettk]

Morning men.

I’ve been trying to track down a small idle issue on my 94 1FZ. I found the link to the old o-ring trick, so I thought I’d give it a shot.

http://www.lcool.org/technical/80_series/fast_idle/fast_idle.html

Well as I started pulling it apart, two parts on the backside of the flange fell out on the bench. I think it’s fairly self explanatory...but I couldn’t find any pictures or diagrams of what it looks like behind the flange, and they are NLA, so I’d rather not take any chances on messing something up.

Do any of you know how these things go back together? I’m guessing the flat side of the spring washer faces up going into the hole on the motor like this...

As far as the other half, from the backside of the flange, I’m guessing it goes...wide bearing, spacer, then the small bearing, which would sit on the flat side of the spring in the picture above.

I’ve got 2 o-rings (completely different from the ones previously mentioned) on order from the local dealer, 90079-60004, and they’ll be here Thursday, so I’ve got some time before all of this goes back together.

 

[enox]

I read that other thread too, what's the idle issue you're experiencing?

I have not taken that apart so I'm not sure how it goes back together..

 

[brettk]

I read that other thread too, what's the idle issue you're experiencing?

So I’m getting CEL code 26, which I’ve read basically translates to rough idle...but it shows up only at certain times and goes away once it’s sat it park for a few minutes. Most of the time the light shows up once I’ve rolled up to a red light or stop sign, the rpms came down to 400 last night on the way home and it came on soon after that.

I’m starting the think the problem was the 2 o-rings I just ordered from the dealer, as they were crispy and one of them was already cracked when I removed the ISC from the throttle body.

 

[brettk]

While waiting on the o rings to come in, I decided to pick up 2 allen screws for the flange so it’s easier off in the future.

If anybody knows how this thing goes back together before I take a shot in the dark tomorrow, please let me know. Thanks!

 

[baldilocks]

So I’m getting CEL code 26, which I’ve read basically translates to rough idle...but it shows up only at certain times and goes away once it’s sat it park for a few minutes. Most of the time the light shows up once I’ve rolled up to a red light or stop sign, the rpms came down to 400 last night on the way home and it came on soon after that.

I’m starting the think the problem was the 2 o-rings I just ordered from the dealer, as they were crispy and one of them was already cracked when I removed the ISC from the throttle body.

DTC 26 indicates a rich air fuel ratio which will cause a less than perfect idle. Are you sure about the direction you’ve taken in your trouble shooting process?

 

[brettk]

DTC 26 indicates a rich air fuel ratio which will cause a less than perfect idle. Are you sure about the direction you’ve taken in your trouble shooting process?

Not at all. I did happen to come across this list after I already took it apart though...

- ground bolt loose
- open e1 circuit
- fuel line pressure
- ECT sensor
- ECM

Once I get this thing back together, I’ll start with those things and see if I can figure something out.