High Idle on my 86 GLHT

[shelbymaniac]

High Idle Problem!

86 GLHT with built 2.5 and t3/t4 turbo. 46 mm tb, 88 electronics with MP computer and 20% injectors. 50 psi fuel pressure. 3" exhaust -no Muff. Vacuum block with lines to the map sensor, BOV, FPR and Wastegate actuator. Checked the AIS, and TPS.

I read all about the AIS on the sticky but still cannot get the engine to idle below 2000 rpm. The idle adjustment screw backed all the way off didn't change the idle at all. No vacuum leaks and the engine starts well. New PCV run right to the 1 piece intake hard line. I can get the idle down but have to retard the distributor a lot, and then as soon as I try and set the timing (CS unplugged) and advance the distributor the idle goes up again.

This has got me stumped as I have been working on these cars for many years. I thought the timing is off 1 tooth, but everything lines up correctly so I didn't change it.
I posted this in urgent as the big Mopar meet is tomorrow and I am having this problem.

Anyone got any ideas???

MOPARMANIAC

[NAJ]

Are there any Fault Codes? If not is the AIS actually moving? Bring the vehicle to Base Idle and remove the AIS and check to see that it actually stepped in to 0.
If it did not step in there is a problem in the AIS Circuit.If it did and with the Vehicle at Base Idle and the Idle Speed is still high the Engine is recieving additional Air from somewhere.With a Central Vacuum Leak the Map sees more Air(Lower Engine Vacuum) and the Controller increases Injector Pulse Width and Advances Ignition Timing hence,Increased Idle Speed.
Use Water or other Non-Flammable Liquid to check for Vacuum Leaks.

[shelbymaniac]

OK I found the problem. MY last turbo went bad and rubbed the housing and sent water and oil through the hoses. I neglected to check my 2 intercoolers and when I pulled the turbo off yesterday to check a problem, there was about 1/2 a litre of coolant and oil in the bottom of each intercooler. That also explains why it was running so rich. I don't know how it even ran at all trying to get air thru all that liquid. My plugs and exhaust were all black and sooted up since it was running so rich.
Now to get the turbo back on.
MOPARMANIAC

[JDre]

I had a bad MP Performance ECU, idle stepped higher each time I started engine, till reached 3000RPM. Could even be bad connections at ECU.