Idle Speed Adjustment

[yoyo13131]

I have a 1993 Eclipse 2.0 non turbo 6 bolt engine

I grounded both connectors to set my base idle....
When the cars completely warmed up the closest I can get the idle is 800-900rpm with the BISS completely closed...

My TPS is set to .502 volts
TPS reads 600 ohms to 4600 ohms
New Oring on BISS screw
FIAV is confirmed opening and closing (I readjusted it in my sink to close when its very hot and open when cold)
ISC is at 39 ohms all coils and I can hear it working.
Idle Position Switch is also working

any ideas why I can't set the idle correctly?

 

[1995gsx20g]

there could be many things.

why are you trying to set the idle?
what was recently done to the car?

 

[yoyo13131]

there could be many things.

why are you trying to set the idle?
what was recently done to the car?

Im setting the idle because I readjusted the TPS from .56 to .50 and would like to be sure the idle is set correctly so the ISC motor can do its job 100%

What made me want to do this is because i've been having cold idle surges...but the warm idles been perfect.

 

[AlaskanDsm]

Have you tried doing a BLT at the throttle body to make sure that you aren't having TB shaft seals leaking or any other leaks?

 

[hhuricane]

Check your timing as well. That can affect idle as well.

 

[yoyo13131]

My cold idle surges are now completely gone! (adjusting the FIAV worked, BISS "was" completely closed for the longest time, so I put a new oring on it and tried to set idle) Only concern is i can't adjust the idle property still (biss screw closes before I reach 750RPM) and I can hear a strange new sound coming from the throttle body, sounds like air being sucked in.... hmmm?

 

[AlaskanDsm]

I would do a Boost leak test as I suggested before.

 

[ReYnd]

Boost leak on a NT?

I'd almost be willing to put money on it being TB shaft seals. My BISS is all the way in and idle is still around 950-1000 RPMs when warm, those seals are what I suspect to be causing the problem. My car hasn't and won't run for a while, so that's one of the small things I'll get to when it's closer to time to get back on the road.

Also, the brass screw rocks. Plastic.

 

[AlaskanDsm]

Boost leak on a NT?

Technically no, but when you pressurize the intake system with a compressor... yes! All you are really doing is looking for leaks whether it is under boost or under vacuum. Turbo cars at under vacuum at idle so you can still be sucking in air unmetered by the MAS.

 

[123abc]

I doubt shaft seals would cause an issue like this. More than likely it sounds like your ignition timing is slightly off or you have a vacuum hose unhooked or something like that.

 

[Dsmj89]

Have you got it checked for any cel ?

 

[yoyo13131]

I doubt shaft seals would cause an issue like this. More than likely it sounds like your ignition timing is slightly off or you have a vacuum hose unhooked or something like that.

I'm suspecting its the shaft seals since everything else has been tested, vacuum hoses are all hooked up correctly and timing was set to around 5 when the engine was rebuilt, I'll check it again since its been 450 miles since timed. (It has brass BISS screw also)

also whats CEL?

 

[Dsmj89]

CEL = Check Engine Light. You probably have a bad sensor at worse even through thorough cleaning, but i'm going to agree with the tb shaft seals as mentioned above.

 

[yoyo13131]

ah, no CEL lights, never seen one ever on this eclipse, even with ISC motor unplugged.

also, where can I get the throttle body shaft seals? dealership says they don't offer the parts and no auto store has them...

 

[ReYnd]

These should be the same for all of our cars. Mach V is the only place I've found them, which is also another reason I've delayed in buying them. Twelve bucks, we'll see about that. Give DSM Graveyard a call, they're my go-to guys for new and used OEM motor-related parts.

Edit: JNZ and STM have them as well.