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Blackmount
01-22-2013, 10:28 AM
So I have this Idle problem..

car insists on idling 1500-2000 rpms...when warm. cold its sometimes higher.

I've checked for vacuum leaks and I have found none.
I have the Biss Screw turned all the way in.
I've adjusting the Idle Timing, and can get the car to idle at 750rpms nicely but driving the car is next to impossible because it runs like complete crap set to low.

I thought if you ground the The Brown Terminal in the engine bay that is suppose to put the ECU in Basic Timing Adjustment mode. which it does (during this time the car idles in the 1000rpm range)

So I set my Base ignition timing to +9.5*
Shut the car off, undo the Terminals start the car again. Back to high idle.
So I ground that Terminal again AND pin 10 under the Dash which is suppose to set the car into Basic Idle Speed Adjustment Mode. So I set then adjust the CAS accordingly and get the car to idle 750 rpms..

but the problem is its adjusting the cars overal; performance too which I thought it wasn't suppose to do when you had both terminals ground? Am I missing something? Please help.

I've gone through many threads similar to this and clicked on many links about idle speed adjustment and most of the threads end without a answer, or the links r dead.

EDIT: I feel dumb, I found a thread today that I have yet seen, and figured out my problem right away... ever since Day 1 I have done Throttlebody Coolant Bypass's on all my cars, but I lived in TN, severe cold was not that big of a deal, so never much thought about it...

Till I found the FIAV/ISC Discussion thread and read this

"As far as I can tell, the FIAV works just like a thermostat. The valve expands with temperature (engine coolant) to close an orifice (air passage that bypasses the throttle body).

When you disconnect the coolant lines from the TB, like I did, whether you uncap them or not (I didn't), all you're doing is depriving the FIAV the heat it needs to close the air passage. With that orifice open, it doesn't matter what the ISC does, it cannot control the amount of air that flows around the closed throttle plate. The result? A normal cold-start idle and an uncontrollable idle surging at operating temp. At least, uncontrollable with my primitive e-manage blue (I can adjust timing and fuel)."

I noticed its not as bad when I park in the garage over night where it stays 20-30* warmer then it does outside, or on the nice days where its 35-40* Outside vs -10* Like today. So now reading that it makes perfect sense.

I' already went ahead and ordered the FIAV Block off plate so we will see what happens.. Hope this can be useful to anyone who has this problem in the future!

Greg E
01-22-2013, 01:29 PM
Great job!

dbest671
01-22-2013, 01:36 PM
Is this on the N/A TT conversion? Did you use a TT throttle body or N/A throttle body?

Greg E
01-22-2013, 03:08 PM
Is this on the N/A TT conversion? Did you use a TT throttle body or N/A throttle body?

Both have provisions for the throttle body coolant lines.

Blackmount
01-22-2013, 04:13 PM
I'm N/A with a TT Plenum, N/A TB

dbest671
01-22-2013, 05:17 PM
Both have provisions for the throttle body coolant lines.

Yes I know this... but I though he had a TT conversion and was using a N/A TB. The N/A throttle bodies don't have the reinforced shaft seals and cannot hold boost. Their shaft seals are nothing more than a rubber oring.

Greg E
01-22-2013, 05:19 PM
Yes I know this... but I though he had a TT conversion and was using a N/A TB. The N/A throttle bodies don't have the reinforced shaft seals and cannot hold boost. Their shaft seals are nothing more than a rubber oring.

Ah I see.

Blackmount
01-22-2013, 06:23 PM
2nd time ive heard that and ive seem alot of cars run TBs from cars not meant for forced induction with no issues. high boost too. like 35+ psi

dbest671
01-22-2013, 06:40 PM
I've bought N/A throttle bodies for parts, they have the same shaft, throttle plate, FIAV, and TPS... the shaft seals literally fall right out once you take off the spring plate and TPS plate LOL. They are very flexible, nothing more than an o-ring.

http://i392.photobucket.com/albums/pp4/hoopb23/Polished%20Throttle%20Body/Rebuild/rebuild012-1.jpg
http://i392.photobucket.com/albums/pp4/hoopb23/Polished%20Throttle%20Body/Rebuild/rebuild006-1.jpg
http://i392.photobucket.com/albums/pp4/hoopb23/Polished%20Throttle%20Body/Rebuild/rebuild009.jpg

R/T93
01-22-2013, 06:45 PM
Depending how the o ring is in there.... I have seen a simple o ring seal 7000+ psi.

From the phone.

dbest671
01-22-2013, 06:50 PM
Depending how the o ring is in there.... I have seen a simple o ring seal 7000+ psi.

From the phone.

Well I imagine if the NA shaft seals were meant to hold boost, Mitsubishi wouldn't have went through the trouble of putting reinforced shaft seals in the TT TBs.

Blackmount
01-22-2013, 07:07 PM
Purhaps a precaution...

but I don't see it being a issue...

alot of people run q45 throttle bodies for example straight from the junkyard... and some of then r running alot of boost like i said...I know the talon was on 38 psi on a Q45 Throttle body

regardless it would not effect idle...as no boost is created at idle.

dbest671
01-22-2013, 07:56 PM
google search q45 and see all the people that shaft leak issues ;) This is just one of many threads about the issue: The "everything Q45" Thread - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com (http://www.dsmtalk.com/forums/showthread.php?t=228700)

I've had a few people ask me if I can rebuild them because they leak... but that TB is a totally different set-up and I don't want to deal with it.

And I saw that you solved your idle issue, that's why I was asking about which TB you have.

Blackmount
01-22-2013, 10:28 PM
the leaking is probably more due to age of the TB and its condition.

anyways get this nonsense off my thread now. please. its irrelevant, and has gone on long enough.

Greg E
01-22-2013, 10:56 PM
Teflon coated green O-rings seal better.

:suspect:

Greg E
01-22-2013, 10:57 PM
Seriously though, I have no idea why mitsu still used this 80s FIAV technology. The ECU is coded to change the base ISCV position based on coolant temp. Maybe they felt another valve was necessary to open airflow even more than the ISC under extreme cold conditions???

Either way, the code doesn't care if the FIAV is removed. In fact, you may even notice better warm up idle from it eliminated.

Blackmount
01-22-2013, 11:11 PM
Well I ordered the Bypass Plate so I can keep my ISC... 15$ shipped, cant complain...also ordered new block off plates for the back of my Intake manifold, as i'm getting tired of seeing my DIY ones I made, I will post on here how it works out!

Blackmount
02-01-2013, 05:51 PM
https://sphotos-a.xx.fbcdn.net/hphotos-prn1/74996_579582115403404_1992366048_n.jpg

I Ordered a new Throttle Body too and it finally arrived today, Id like to thank Mike (unhealthyhoarder) for sending me one for the price of shipping!

It was nice too because it came with a Metal BISS Screw as oppose to the Typical plastic screw that I always seem to strip and or break with my awesome Superman Screwdriver Strength...

the Plate definitely fixed my idle and allowed me to adjust the BISS Screw down to 750 rpms at Warm Idle (Coolant temp of 190*)

This was a EBAY plate too. The Bypass not the Block off, This allows you to still run your IAC.

Greg E
02-01-2013, 07:06 PM
Glad to hear it!

Jimvr4
02-01-2013, 08:09 PM
Might want to put a new FIAV gasket in there. MD614406 is the number. Related stuff:
MD608806 - Biss o-ring
MD614948 - Biss screw
MD614532 - Biss cap- most people are actually missing this little plug/cap

Blackmount
02-01-2013, 11:21 PM
Gasket is good.. im keeping metal Biss screw. I put fresh o ring on it and i plugged it

ilian51378
06-23-2013, 11:47 PM
I don't want to hijack your thread, but I am doing a TT conversion right now and was thinking about using the N/A throttle body on a T/T plenum. I don't know hoe to connect the vacuum lines on it though, since there is only one coming out of it and the other two are blocked off... I bought the TT seals for it, but now I don't understand how the vacuum lines will hook up. I am only asking this question, because I am desperate to finish up my car since I can only use the garage on weekends and all my parts are sitting there, taking space... I saw you discussed this in this thread and figured you would have more experience with it than me. Any help is greatly appreciated. Thanks!

Jimvr4
06-24-2013, 12:42 AM
Thread starter is banned.

Greg E
06-24-2013, 08:02 AM
Thread starter is banned.

Was an OT bump anyway.

dbest671
06-24-2013, 12:05 PM
I don't want to hijack your thread, but I am doing a TT conversion right now and was thinking about using the N/A throttle body on a T/T plenum. I don't know hoe to connect the vacuum lines on it though, since there is only one coming out of it and the other two are blocked off... I bought the TT seals for it, but now I don't understand how the vacuum lines will hook up. I am only asking this question, because I am desperate to finish up my car since I can only use the garage on weekends and all my parts are sitting there, taking space... I saw you discussed this in this thread and figured you would have more experience with it than me. Any help is greatly appreciated. Thanks!

You can't hook up the other two vacuum lines on the throttle body... you'll have to find somewhere else (vacuum reduction write-ups should help you with this).