High idle (Page 2/6)
Scuba_steve45 SEP 18, 12:36 PM
I’m not by the car now but I’m 95% sure the throttle plate was kinda open at idle. I’ll double check today and keep you posted. About the brake booster line too.

quote
Originally posted by 82-T/A [At Work]:


If it is... you'd see it immediately... as in, with the air cleaner off, the throttle plate would be pitched open somewhat. When the car is idling, the throttle plate should be completely closed... that's because the IAC (as Yellow-88 mentions) gets its air through a separate passage in the base of the TBI unit, which bypasses the throttle plate. So just to reiterate, when the car is just idling, the throttle plate should be completely closed.


... but yeah, post some good quality pictures tonight, and we'll take a look.
82-T/A [At Work] SEP 18, 12:58 PM

quote
Originally posted by Scuba_steve45:

I’m not by the car now but I’m 95% sure the throttle plate was kinda open at idle. I’ll double check today and keep you posted. About the brake booster line too.




Take a picture of the throttle linkage then too... there are a few things you'll want to check:
- Whether the cable is properly seated on the bracket.
- The intermediary bracket with extension tube (I'll take pictures so you can see)
- The return spring (usually yellow, unless it's rusted... I'll take pictures of this as well)

It could just be that the throttle is getting stuck in the TBI.

But, it may even be as simple as the gas pedal getting stuck on the floor mat. This is literally a thing that happens (and has happened to me) when you replace the carpets with aftermarket ones, sometimes... so check that too.
Scuba_steve45 SEP 18, 05:36 PM

I’m not sure if this is what you want to see but here is the throttle. The throttle cable seems fine although I don’t know what to look for lol.

quote
Originally posted by 82-T/A [At Work]:
Take a picture of the throttle linkage then too... there are a few things you'll want to check:
- Whether the cable is properly seated on the bracket.
- The intermediary bracket with extension tube (I'll take pictures so you can see)
- The return spring (usually yellow, unless it's rusted... I'll take pictures of this as well)

It could just be that the throttle is getting stuck in the TBI.

But, it may even be as simple as the gas pedal getting stuck on the floor mat. This is literally a thing that happens (and has happened to me) when you replace the carpets with aftermarket ones, sometimes... so check that too.

[This message has been edited by Scuba_steve45 (edited 09-18-2024).]

Dennis LaGrua SEP 18, 05:50 PM
X 2 a vacuum leak. Buy borrow, rent or build yourself a smoke machine. Feed the smoke into the intake manifold (engine off) Get an LED flashlight and watch all around where the smoke is seen coming out. There is your leak. If you lived closer we could do this for you as it only takes a few minutes.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Scuba_steve45 SEP 18, 06:19 PM
I take what I said back… the throttle play is closed on idle.

quote
Originally posted by 82-T/A [At Work]:


If it is... you'd see it immediately... as in, with the air cleaner off, the throttle plate would be pitched open somewhat. When the car is idling, the throttle plate should be completely closed... that's because the IAC (as Yellow-88 mentions) gets its air through a separate passage in the base of the TBI unit, which bypasses the throttle plate. So just to reiterate, when the car is just idling, the throttle plate should be completely closed.


... but yeah, post some good quality pictures tonight, and we'll take a look.
cartercarbaficionado SEP 18, 06:34 PM

quote
Originally posted by Scuba_steve45:

I take what I said back… the throttle play is closed on idle.


bro I can litterally see a vaccum line leak in the photo. use zip ties instead of hose clamps for vaccum line or ya know buy the right size and I can see the remnants of crumbling line so check your booster line into the manifold that's on the drivers side
Scuba_steve45 SEP 18, 06:40 PM
I was using the size that another person used and they said worked fine. I have always used the metal hose clamps on the ends of vacuum lines as well and it worked just fine so I assumed it would be fine on this engine as well.

quote
Originally posted by cartercarbaficionado:

bro I can litterally see a vaccum line leak in the photo. use zip ties instead of hose clamps for vaccum line or ya know buy the right size and I can see the remnants of crumbling line so check your booster line into the manifold that's on the drivers side



82-T/A [At Work] SEP 19, 03:38 PM
I don't know if you still need pictures, but I'll take several tonight... just been working late. But I'm off work now, and heading into the garage. I'll post them tonight.
Scuba_steve45 SEP 19, 03:40 PM
Yes please… I’ve been trying to post pictures of my vacuum lines but everytime I add a picture it tries not to let me lol

quote
Originally posted by 82-T/A [At Work]:

I don't know if you still need pictures, but I'll take several tonight... just been working late. But I'm off work now, and heading into the garage. I'll post them tonight.
Scuba_steve45 SEP 19, 04:40 PM
Just did a smoke test a few minutes ago and every time the smoke just came out of the top of the throttle body even when I plugged it with a rag.

quote
Originally posted by Dennis LaGrua:

X 2 a vacuum leak. Buy borrow, rent or build yourself a smoke machine. Feed the smoke into the intake manifold (engine off) Get an LED flashlight and watch all around where the smoke is seen coming out. There is your leak. If you lived closer we could do this for you as it only takes a few minutes.