Hey Guys,

I just finished going trough my orinigal 91' TII to remove the rats nest and replace the intake manifold gaskets. The car started and was running great, then I revved it up and held after it had been running for about 10 minutes. That's where it all started. As soon as I let off the gas it dropped back down and started jumping/hunting between idle and 1500rpm, It would still rev up fine. I cut the car off and let it sit for a few minutes, then tried to start it again and it just took off to 5krpm and it slowly rises.
I unplugged the BAC and tried it, no dice.
I unplugged the Boost/Pressure sensor, no dice.

I gave up for the night(it's dark and raining), I just wanted to get input from you guys before I go back to to check it out tomorrow if/when the rain stops.

Again, the car is a 91' TII
The work I just did:
Remove the rats nest and keep BAC/IAC. I followed other peoples writeup on how to re-route the vacuum lines, and like I said- the car WAS initially running perfect.
Blocked off OMP
Blocked off Split air Pipe and ACV.
Install 720CC seondaries(they are the correct high impedance injectors)
Replaced intake manifold gaskets, and all gaskets and O-rings with what I took apart.
Oil pan gasket
All new coolant hoses

Mods:
Rtek 1.7
FD fuel pump
3" turbo back exhaust with cat.
Ported wasgate on the Turbo.
FC1000 on primary coil
Koyo w/ taurus fan
Greddy BOV
Racing beat MBC(it is set to wide open right now, so it has no effect)
Innovate LC-1 wideband
Twin disc clutch w/ LW flywheel.
FD alternator w/ dual sheave pulley
Turbo blanket

The airbox and TID are stock.
I still have PS
A/C is there, but the belt is currently off, and it's low on refrigerant.
The throttle cable and cruise control are not stuck. The TB is closed all the way when the car is off.
The car did previously sit for a year, that's why I went through and replaced everything.

Please brainstorm with me and Help me out!

It just crossed my mind, is it possible for the AFM to be stuck?

 

Check the TPS!

 

stuck throttle body.(my guess)..easily checked, takes one minute
The cable may move but the shaft that the butterflies sit on would stay put.
take off the throttle body inlet just make sure that when you move the Throttle body shafts that they are returning back to idle and the Tb is closing.

 

I was thinking this too, it revs up to about 5500-6000RPM and then slowly goes up after that.
The only thing that didn't make sense to me was that before it started doing it I had the hunting idle. I shut it down, then when I restarted it, it took off.

Th damn car only has 83K on it, I hope its an easy fix.

 

Make sure the CAS is set properly. Look at the throttle linkage at the front of the engine and w/the car idling at a high rpm push "upwards" on the throttle linkage and see if this brings down the rpm. If the throttle cable twists it can pull the linkage open. The cable should be removed from the throttle body when this part of the engine is removed to prevent it from twisting incorrectly as opposed to being left in place when the throttle body is removed.

 

I never touched the CAS, but I'll double check it when I get the chance.
I'll also check the TB more thoroughly, I did check the cables and rear of the TB when the car was off earlier. There was slack in the cables and when I pushed down on the linkage it had resistance.

I really wish I had a garage, I'd be out there checking it out right now!

 

And if the car has cruise control then check that cable as well. If you didn't mess w/the CAS then you could forget about it being the problem.

 

Yeah, I checked it, and it's loose. I'm hoping it's just stuck throttle plates.

It has to be something so dumb that It's looked over. The car ran hitch free and idled right at 750 until I revved it up and held it.

 

5K is gonna be the throttle plates. thats a lot of air getting in the motor. Unless you have a huge vac leak somewhere. but its gonna be the throttle plates.

 

I had this happen to me. I did the TB mod wrong, and it sometimes allowed the secondary throttle plates to get stuck open. Mashing the gas pedal furiously helped get it un-stuck. CHECK YOUR TB!

 

Tps will make it hunt from 500rpm to 1500rpm... i just went thru that... Like the others said, it sound like throttle plates. Let us know what it was when you figure it out or if you fixed it already.

 

Well, I went out and finished getting the car road worthy today. It still needs a few things done, but it's driveable and legal!(minus a valid VA safety inspection). The fan controller also crapped out. How come every Thermostat controlled fan relay ***** the bed? The relay function still works, but the thermostat control doesn't. I just hooked the optional A/C wire up to the igntion power source at the test connector behind the battery. Now it just runs all the time when the car is turned on.

Anyway to get to the issue at hand. What I had to do to fix the car today- Absolutely nothing. I stated it up and it ran like a dream. It must have just beeen stuck throttle plates.
Now I'm having a bogging under mild to heavy load at 3500rpm between when the primaries drop down and secondaries come on(AFR's lean out way too much). It's an Rtek isssue, so I'm going to check that section of the forum.
It's weird though, if you hit it WOT from a dig it doesn't bog, only when you're cruising below 3Krpm and go into boost. If you're cruising at 4k and hit it you're fine.

Thanks for you're help. I'm glad the problem worked itself out!