Backfires, no driveability, I'm stumped

Desert Stallion

Founding Member
Aug 5, 2001
651
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16
Queen Creek, AZ
Well, I'm trying to trouble shoot this new car, '86 speed density HO motor. The problem is that if the car is warmed up, it won't run for crap. You touch the accelerator, it coughs, backfires and wants to stall out. It won't even idle right. If it's cold, it'll run and drive okay for the most part, until it starts to warm up. If it's warm and you let it idle with the SPOUT plug pulled, it'll idle okay, but you can't add throttle or it'll try to backfire, etc.

Computer throws codes 12, 14, 44, and 94. Well, 12 is a idle speed control code, 14 shouldn't apply to this car as far as my manual is concerned, 44 is Thermactor air system failure, and 94 is Thermactor systme inop bank 2, or usually AIRD failure.

Sure enough, the AIRD was malfunctioning, so I replaced it with one I had laying around that works, no change. I also swapped TFI modules early on before I had codes to work with, and that didn't help. I also replaced and cleaned the PCV and screen and adjoining hoses because it looks like the old PCV was dead and causing the motor to breath backwards, that is back through the TB through the oil filler neck in the valve cover.

I know the air pump works, and I know the air bypass (first valve after the pump) works. My thoughts are corroded wiring to the AIR solenoids, or maybe one of the solenoid's are shorted? The AIRD solenoid still pulls vacuum because there's vacuum at the AIRD.

So what do y'all think? This problem has kept the car undriveable for a few months now (that's why I got it cheap :) ) and it's time to put it back on the road. I'm really kinda stumped on this one.

Thanks all.
 
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code 14 is for the PIP (Profile Ignition Pickup) inside the distributor. it applies to cars whether they are manual or auto. if the PIP isn't working right then the car doesn't run right.