94 454, GMC Suburban -Idle Air Control, O2, TPS, Fuel Pump relay all replaced-still code 12, 36

[jamesT]

Unhook the throttle cable from the TBI linkage and see if the idle returns to normal. I have had to replace the throttle cable on several of my trucks. The metal cable eventually wears in to the sheath material causing the cable to stick resulting in high idle and/or higher than normal effort to depress the throttle pedal.

Great advice I'll give it a try. Thank you.

 

[jamesT]

Okay, going to try the throttle linkage trick.

Light still on, stalled today after running 5 minutes.

Replaced spark plugs with platinum, new cap and rotor.

Previous owner had massive spark plugs with an enormous gap. Like, .054. Could be that running that way for so long led to carbon and excessive buildup. Maybe my O2 sensor, is gummed up because I replaced that sometime ago and it ran great for a little bit.

Running out of options, set to leave here, but with a limping town vehicle. Oh, yah and my hydroboost is leaking, probably not good to tow with.

No mechanics around here that can help really. Anyone know of anyone in North Dakota with 90's GM/CHEV experience?