first4runner

I just bought everything I needed and took the silencer box out and hooked all of the vacuum lines back up made sure everything was sealed and started it up and my idle went down to around 700 (normally 1k) I really didnt notice anything different in power tho. Well somehow I had a leak somewhere and could not find it. So I put the box back in and now it is leaking still I cannot find a leak anywhere everything is super snug. It could be the type of duct I am using that is causing turbulence but that still does not explain why my idle has gone down, I had to turn my idle screw 180 degrees to get a smooth idle out of it now.

first4runner

Oops meant to ask if anyone else has had this problem and what they did to fix it? And did anyone elses idle go down after they did the mod?

midiwall

So, "sucks" as in "isn't any good" or "there's a vacuum leak"?

Here're a couple of ideas on how to find a vacuum leak...

http://answers.yahoo.com/question/in...1191939AAz2ivf

Googling will pop-up more:
http://www.google.com/search?hl=en&q...uum+leak+spray


Mine's been done so long I don't remember if the idle dropped - as you say, it's probably from a vacuum leak.

We're talking about different engines (between you and I) of course, but I'd think that 1000 RPM is kinda' high to start with.

faubrunner64

anywhere between 750 and 1k is ideal and i know the engine will change it due to different driving conditions, but yeah id bet that you have a leak somewhere there. Spray carb or brake cleaner around all the clamps on your ISR mod and listen for a jump in the idle and then you will find your leak!
good thisng you know its a centralised area.

first4runner

sucks as in I noticed NO difference with the silencer on or off

and

sucks as I am pretty darn sure there is no leak (I replaced all hoses and clamps) I am pretty sure it is turbulence, but it still does not explain the idle rpm's dropping

first4runner

I will say that it is not an erratic idle. Its pretty smooth even at 700 so it could just be due to the fact that you always seem to notice things and sounds better when you have just replaced a part or something, so has anyone else had this problem?

jrock

just like doing the deck plate mod, you need to remove the ECU fuse to reset the levels. The ECU will then re-learn the ratios after a little driving around. Not sure about a leak though...?

Dublin

Did mine over a year ago, before the mod 850 after 850. Only changes were better throttle responce and it sounds cool. Betting on a vacume leak somewhere. Just because it looks,feels and seems tight doesn't mean it is, possibly some line loose near the mod. Hope you get it figured out.

midiwall

ummm... The results of doing the ISR shouldn't affect anything the ECU sees... (read below)


(jrock) this is what the ISR mod is about. It reduces the volume of the pathway between the airbox and the TB. Less volume means less stuff to fill when you mash the pedal which means quick throttle response.

oh... and the increased noise level.

Anyway... there shouldn't be a need to reset the ECU in order to see the effects, though it's never a _bad_ idea to do so.

olharleyman

Spray carb or brake cleaner around all the clamps on your ISR mod and listen for a jump in the idle and then you will find your leak!
I agree that's how I find air leaks on big bore Harley motors and it works great.
I did my isr over a year ago and it just last week loosened up on me and looking at it you would never see it but it killed my power completely as I was driving home from work at 10:30 at night.
It just so happened that I had a can of break clean with me to do a leak test on a 124 inch Harley motor in my garage at home so I sprayed it around the rubber tube fitting between the t/b and pipe low and behold the idle jumped about 2 grand shut off the runner tightened down the clamps ALL the clamps and have been trouble free since.

ChickenLover

FWIW, the most noticeable gain from my ISR mod was at the top end of the rpm band (3,500 - 5,500).

whitedevil666

first grab ahold of all the spark plug wires on that side of the engine. then have your buddy start it. if you get lit like a christmas tree then fix the plug wires. if this doesn't work look for what else you broke. **not dissin'** i break stuff all the time.

91TPU

you said that idle is not erratic, just lower...did you do anything else while doing this mod?

first4runner

Well I was hoping to change out all of the wires anyways so this is a good excuse to do so. And I will probably break out the carb cleaner this weekend and do some expirementing. I hope it actually is a leak that way I can get a sure fix. Thanks guys.

JEBSR5

I'd like to try the mod on mine, but haven't figured out the AFM end of it yet. After hearing your problems, not sure I want to now.

Paul H.

I keep my idle at 750. When I did mine I did notice better throttle response and it is louder too.

traben27

I had this problem when I first did my ISR mod. I was positive that there were no leaks either and after four days I finally found one on one of the couplings. The only reason I didn't find it faster was that it was right on the edge of one of the clamps so it was very hard to see. Just make sure you check EVERYTHING.

Of course I can't tell if you mean you put in a whole new pipe, or just took the intake silencer out.

^VooDoo^

Pics!!!, Im betting A/C and Powersteering idle up hoses are not hooked up correctly and making a major vacuum leak.