Throttle body to fix

[Srt4RacerDave]

I've been battling with idle surge for quite some time now. I threw in a new ISC, and it still surged for about 2 weeks, and then it was good. I took out the throttle body and replaced the seals, still no progress. I can't feel any air getting by the BISS screw either. If I was to just buy a replacement throttle body that didn't have idle surge, would that guarantee to fix the problem? I know idle surge is caused by air getting past it. I can get my hands on a new throttle body for pretty cheap. Just want to make sure this is what I'm looking for. Thanks in advance.

 

[DSM_PWR]

Have you done a boost leak test to see if the TB is still leaking? or if anything else is leaking?

 

[Srt4RacerDave]

Well, I've fixed a lot of boost leaks over the downtime of my car (See drivetrain thread...). I'm sure I still may have one somewhere though. But the throttle body doesn't APPEAR to be leaking anymore. Isn't the problem caused specifically by air getting passed the throttle body? If this is the case, wouldn't a throttle body that didn't have idle surge previously fix my idle surge?

 

[Gstclipse69]

Yes a throttle body that doesnt have idle surge should likely fix the problem. I would look into your deleting your FIAV on the lower half of your throttle body.

 

[Dsmj89]

Re-check all your sensors are plugged in and make sure you have no vacuum lines loose anywhere, inspect all over the car.
Also make sure your t-stat isn't stuck/broken.

 

[Srt4RacerDave]

Yeah I've done the usual inspection. I was an idiot for buying a brand new ISC, when I could get a used throttle body for 1/10 the price. Seems almost too good to be true. Why don't people just suggest to replace the t/b to fix idle surge, instead of all that other crap?

 

[Spoolin4Ever]

Yeah I've done the usual inspection. I was an idiot for buying a brand new ISC, when I could get a used throttle body for 1/10 the price. Seems almost too good to be true. Why don't people just suggest to replace the t/b to fix idle surge, instead of all that other crap?

It's probably the FIAV, the only way to know for sure is you now must pull the throttle body, pull the FIAV, and replace with FIAV blockoff plate. I was in EXACT same situation, got fed up and got the blockoff that also blocks off the ISC motor. Started car and idle surege was gone.

The reason everyone is not just saying buy a known good throttle body is because:
1. Brand new is expensive

2. Used will be good now but will probably be going out soon, as these cars are all getting old.

3. An FIAV blockoff plate is cheap.

4. The seals, ISC, FIAV or any other part could go out on the used one anyway, and you just rebuilt yours. You want to buy a used one and have to pull it off in 6 months because of idle surge again (FIAV)?

5. Used online never know for sure till you get it how good it is, could get ripped off.

By the way, when your FIAV starts going out, it is rather gradual, and here are the symptoms:

1. Biss screw is turned in almost all the way to keep idle from going too high.

2. Bad idle surge (comes later).

2. Free mod this creates:
COOLANT INJECTION! "Is that moss growing in your intake?", why, no it's coolant injection!

3. Exhaust is slightly sweet smelling, and you have to add a small amount of coolant every 3 months. Makes you think the head gasket is going out, but it's not. It's the FIAV going out, and leaking coolant int your throttle body and sucked into the intake. Look for green stuff in the intake if you have a bad idle surge.

3. Warning: temporarily allows you to run more boost then you actually should be able to. Then when you swap out the TB, or fix the problem you will knock and burn a valve. Oh wait, that was me . So if you are running more than stock boost on stock fuel, make sure and turn it down before fixing your FIAV (braoken FIAV=coolant injection)

4. Car very inconsistant, sometimes fast as hell other times knocking/pulled timing/slow.

 

[Srt4RacerDave]

Well to be honest, if a used throttle body that DOESN'T idle surge will fix my problem, even for the 4-6 months that you say a used one will last, I'm willing to pay the 30$. If 30$ every 6 months is what it costs to be idle surge free, I'm willing to be it honestly. I haven't noticed any coolant in the places you noticed. So, to sum it all up, throwing in a throttle body that isn't idle surging will definately fix my idle surge, even if just for a while?

 

[1992GSX]

More than likely yes, but in all honesty I would just go ahead and delete the isc and fiav. Its much simpler and cheaper to do that once rather than have a annual or semi annual throttle body replacement.

 

[Srt4RacerDave]

Simple is what I like best..

So it's good to know that a new t/b will fix my idle surge. For reference, was this the block off plate you were talking about?

FIAV Block Off Plate - Talon Mitsubishi Eclipse DSM:eBay Motors (item 280379519677 end time Nov-28-09 01:24:45 PST)

Do you block off the ISC AND the FAIV, or just the FAIV?

 

[Spoolin4Ever]

Simple is what I like best..

So it's good to know that a new t/b will fix my idle surge. For reference, was this the block off plate you were talking about?

FIAV Block Off Plate - Talon Mitsubishi Eclipse DSM:eBay Motors (item 280379519677 end time Nov-28-09 01:24:45 PST)

Do you block off the ISC AND the FAIV, or just the FAIV?

I did not buy mine on ebay, so I can't say 100% if it is the same one.

There are 2 different style blockoff plates like I already said. It is your choice if you want to block FIAV only, or block both, like I already said.

I got the one that blocks both isc and FIAV.

When I bought mine, I found out more info by searching. I used the search titles for fiav blockoff.

 

[Srt4RacerDave]

Do you need to block off both? Or does it not really matter?