Idle and throttle bad after replacing tons of stuff. Please help

[RobertC]

Throttle Position Switch, there are 2 micro-switches for idle and WOT.

Sometimes on old engines, engine oil blowby will get into the throttle body and leak down into the TPS and interfere with correct operation.

This could be a potential problem in your situation, worth checking out.

Stats are in the Bentely manual.

[Rtheriaque]

Double check your plug wires. Sounds like you may have crossed something on the cap.

[jlevie]

The most likely cause is intake leaks. A smoke test will find them.

[petmybadger]

I have a 88ix. I recently was having an idle issue where it was revving up to 1500 and holding there. I figured this was probably a vacuum leak. I proceeded to replace the following just to be safe and it needed a tune up anyway

Injectors
Fuel rail
FPR
Fuel filter
All vacuum lines, boot, etc
Fuel line going to and from rail
Cap, plugs, rotor
O2 sensor <6 months ago

Now the idle speed is steady at 650-700. The issue now is that while the idle SPEED is perfect, the whole car is bouncing. The exhaust makes a "putt-putt" sound while it idles. When throttle is engaged ever so lightly, the RPMs dip to the point of almost stalling then goes back to normal. I took it for a 5-10 minute drive and it felt as if it was running with half power. This is quite troubling. I've read through many different posts. I cleaned the ICV, throttle body and AFM, still nothing. Checked for vacuum leaks, nothing. Anyone have any other ideas?