While replacing a FITV hose, the main distributor connector was knocked loose. It must have never been fully engaged, and it appears that no wires were damaged, as it must have unplugged easily. Not surprisingly, it threw a code 4 when trying to start. The problem is that it keeps coming back after clearing. I've heard of someone having this identical situation, but there were no answers posted. I highly doubt that the crank sensor was damaged, and that it would coincidentally just decide to have a problem at that moment. After clearing the code, it will take anywhere from 30 seconds to 1 minute of driving to come back on. I'm convinced it simply will not clear from memory as it's supposed to, when clearing the code.

Is there any solution for this? I still need to try letting the engine idle for 10 minutes without touching the accelerator after resetting and then shutting off, which I just came across. Maybe that will work.

 

 

I'll state again about how this happened to be clear. The distributor plug accidentally was unplugged while replacing a FITV hose, and then I attempted to start the engine. That is what threw the code.

The code was generated by trying to start the car, with the connector off. Before a full troubleshoot, I have difficulty believing that the crank sensor or the wiring were damaged. The connector must have not been latched, and probably easily unplugged. No wires appear to be damaged. I would ***** wires for an ohm check if I had to, but it does not appear to be the problem. The pins and connectors are clean, and have never been a problem in the past. If there was any damage done, it would be on the harness end, making checks from the distributor plug end irrelevant.

Edit: Did wire ***** test for the heck of it, showing 450 ohms across the engine harness side of the connector which is in the center of acceptable range. This rules out any damage to either side of the connector and related distributor harnessing.

The code does not immediately throw again either, after resetting. It appears that this scenario causes some software glitch that was not anticipated, and that the code will not fully clear.

This problem has happened to someone before, but there were no answers to the post. This is not the standard "component went bad now replace" situation. I'm not jumping at buying an ECU, due to simply trying to start an engine with the distributor not plugged in, throwing a code that is now corrected but refuses to clear. I've never heard of this issue damaging ECUs, but maybe it does?

 

I'm surprised this info isn't published, since the standard code clearing procedure doesn't work. Seemed to have solved this problem by discharging the computer by connecting the computer supply terminal (not the batt+ terminal) at the 15A hazard fuse to ground, after pulling the fuse. Looked it up after finding this solution, and apparently this is done on other vehicles also, but could only be found after using very specific search terms, including grounding. Another site suggested this, which is essentially the same thing: "Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory."

 

Unfortunately, it is possible that this is just what has happened.

I can`t find it just now, but the factory shop manual has a warning about never allowing the thick white wire from distributor to ECU to become disconnected while the ignition is on. Do do so, as I recall, results in damage to the ECU.

 

Thanks for the reply and that's what I was thinking. Not surprising that this info isn't published. It would be nice if they had designed the t-stat/IACV/FITV and related hosing to be a bit more serviceable, as well as making a connector that easily snaps in. I probably just bumped it very lightly which caused it to unplug, as it was never fully latched from previous work. The IAC and FIT valves are properly named, as servicing them and their hoses is a fit.

Edit: I drove the car again and the code seems to be cleared. Grounding out the non powered terminal at the 15A hazard fuse under the hood seems to be the ONLY way to clear it. Removing the fuse alone will only clear it until you drive for 30 seconds to 1 minute.
Edit: As of 12/6 the code is still clear and all good.

Like the bad fuel pump relay solder joints and 16V ICM capacitors, I'm sure this info is not published in the original factory manual. Just for the heck of it, I opened up my old fan timer last night, and sure enough it has the same 16V, 47uF capacitors in it. I would bet if I replaced those, I would have a good spare fan timer unit.