| I wanted to post a follow up to the solution to my earlier problem I posted about here. I suspected a bad ground of the radio had caused some of my previous issues, so I removed it. But the car still wouldn't start. I ran codes and got a code 21, ignition circuit. So per the service manual, I proceeded to do lots of troubleshooting with a multimeter. This involved removing and testing the PTU and swapping out with a know good one, removing the CAS and manually turning to test - tested good because I heard each injector click, testing the continuity of the PTU sub harness and wires, CAS wiring, wiring to ECU, swapping out EGI and IGN relays, removing and testing the fuel pump relay, removing the APEXI boost control solenoid from the circuit, checking the wires at the ECU. Everything tested fine. So I went back to the basics and I removed a coil pack and looked for spark against the plenum. Which to my surprise I discovered I did have. (I always thought a code 21 was a problem preventing the spark so did not even consider doing this first when I saw the code.) After verifying I had spark, I moved on to fuel. I knew the relay was good so that left the fuel pump or fuel pump control unit. I found a write up on line on how to bypass the fuel pump controller on wikispaces so thought I'd do that first. Followed the instructions, spent $7 on parts and 20 minutes to create the jumpers and wire up the bypass. I turned the key and lo and behold the car fired right up strong. Finally. Maybe the fuel pump controller had just worn out from old age, but my theory is the aftermarket radio's poor ground caused voltage to leak by and over the course of a few months finally fried the circuit along with causing the other electrical gremlins like my boost controller to continue running for several seconds after the car was shut off. Anyway, the moral of the story is when you're trying to diagnose a problem, don't get side tracked by sounds, codes, or information overload poring over posts here on the internet or tt.net . Do the very basic mechanical things first to determine if the problem is fuel, spark, or air related and then do all those other things. Oh and remember that a the fuel pump controller is part of the ignition circuit when a code 21 shows up. Cheers.
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