Blu as 270,000 miles on him and a 2nd engine.

 

Over the past year his idle has been odd for the last year, I thought he needed plugs. His gas mileage was down in the 18 mpg range for city driving. I blamed that on stop signs popping up everywhere. I put plug on my Honeydo list.

 

Finally the idle would not come down from 1000 rpm. I cleaned it and I killed it. I ordered a used tested one off ebay. I removed and noticed someone left a bolt off, That told me it had been replaced before. I also learned why that one bolt was missing. Since he ran fine missing that bolt, I did not bother either (after using every "mechanics terminology" i knew).

 

Blu's idle was silky smooth. I don't think it has been that smooth since I owned him.

 

The surprise. My city MPG went up 20% (and my driving habits have not changed). My highway driving is now hitting the 27-28-29 he used to hit.

 

Just something else to look at with a high mileage sooby that has a intermittently rough idle, lower MPG, and no codes.

 

nipper

Very interesting....does this process translate to the phase I ej25? I have done plugs and wires and still the car idles low and rough. I am planning to pull it into the shop for a timing belt service and transmission/diff drain in the near future, so as long as I have the time I wouldn't mind taking a stab at the idle while I'm there. You'll have to excuse my ignorance, but I honestly don't know how adjust the idle on my own car. It is not throwing any codes and is currently sitting at 410,000 kms (256,000 miles?).

I jsut replaced the IACV on my 97 OWB. I only put in the top 2 bolts. I couldn't get to the bottom two. When I took it out it only had 3 bolts anyhow.

 

Tho my idle isn't much improved. Still getting P0507.

the last 2 I've seen only had 3 bolts. missing one on the bottom

Edited October 28, 201015 yr by Tahoe Subaru

the last 2 I've seen only had 3 bolts. missing one on the bottom

 

 

Hehehe I guess everyone gives up in that bolt.

I jsut replaced the IACV on my 97 OWB. I only put in the top 2 bolts. I couldn't get to the bottom two. When I took it out it only had 3 bolts anyhow.

 

Tho my idle isn't much improved. Still getting P0507.

Thats because you only have two bolts. This causes a vacume leak. You can get the bolt in that is closest to the radiator. A mechanics trick - Use a peice of thickl paper or painters tape in the socket, gooey side to the socket. Jam the bolt in the socket, making sure you can get your scket off the bolt. The bolt does not have to be in there tightly. This will hold the bolt in untill you get it in the hole.

Thats because you only have two bolts. This causes a vacume leak. You can get the bolt in that is closest to the radiator. A mechanics trick - Use a peice of thickl paper or painters tape in the socket, gooey side to the socket. Jam the bolt in the socket, making sure you can get your scket off the bolt. The bolt does not have to be in there tightly. This will hold the bolt in untill you get it in the hole.

 

I had the P0507 before changing the IACV. I will put in the last bolt.

I had the P0507 before changing the IACV. I will put in the last bolt.

 

So did I.

Alright then.

 

Do you know what size and length the bolt is? I tried to get the bottom one in but I dropped it in the engine and it disappeared forever. I think I might have to go to the hardware store and replace it.

 

I guess I can take the old IACV with me to the hardware store and see what fits?

Edited October 29, 201015 yr by bstone

IIRC, it only has 3 bolts, but it does have a extra hole for some reason:confused:

 

 

 

the last 2 I've seen only had 3 bolts. missing one on the bottom

IIRC, it only has 3 bolts, but it does have a extra hole for some reason:confused:

The gasket has four holes, maybe it is for thermal expansion. i also found a few other things that were in "the valley of the lost"

i'm likely to show my ignorance here, is this thing, iacv, bolted on the intake manifold just to the right, passenger side, of the throttle body? more or less just above the pcv valve?

 

if so it has 4 bolts, i was swapping a 2.2 and since i didn't plan on reusing the engine i was pulling i decided to remove said device for better access to the TC bolts. i removed 3 bolts and the damn thing wouldn't come off. i finally found the 4th bolt down low and recessed, and removed it and then the thing just fell off.

 

IIRC not all of the bolts are the same length.

 

i reattached it after i got the engine out and even then it was not easy to bolt up. so i can only imagine the difficulty with the engine in the car. probably harder than the knock sensor, at least it only has one bolt.

Edited October 31, 201015 yr by johnceggleston

IIRC, it only has 3 bolts, but it does have a extra hole for some reason:confused:

 

That does explain a lot, actually.

Nipper, thanks for sharing.

 

I think this post may be what gets me to finally clean (or replace) my IACV. Just passed 200.000 miles, and the idle is slow to come down, and there is a slight surging when cruising around 2000rpm in 4th gear - manual, Euro model.

 

My mileage could be better too

 

 

Wonder if your success will be repeatable with a 1999, MAP based engine. The IACV is quite different.

Went to the hardware store and got a 1mm pitch bolt. Was very careful and got it into the bottom hole in the IACV. Will take it for a drive and see if there is any difference. Gosh I hope so.

I think that may be like the issue I;m having as well, but the Idle Air Control Valve is so damn expensive.

would this being bad make the car idle very rough when warm. i'm have a rough idle and if you listen to the tailpipe you can hear it sputtering alot. otherwise it runs great. and no cel's

would this being bad make the car idle very rough when warm. i'm have a rough idle and if you listen to the tailpipe you can hear it sputtering alot. otherwise it runs great. and no cel's

 

 

It could, but before thgere is a run on IACV's you should rule everything else out first. CEL's are only tools, not the solution to all running issues.

 

Start a new thread for yours and lets see where we can go with it.