Question Regarding my Busted s14

[TimzSE]

Hi all, I'm new to these boards, and so far I have found them to be some of the most informative anywhere! So, I'm hop[ing maybe you guys can help me diagnose my 1995 SE's problem.

The car/engine have 133K and I keep her well lubbed and well maintained. However, about a week ago, it wouldn't start. On my second attempt to start it, the CEL came on. I pulled the codes and got a 33 (o2 sensor) and a 103 (Park/Neutral Switch). I've gotten a 103 before, and the car still ran even when the CEL was on and after I cleared it. But the 33 code is new. I don't think the CEL code for the o2 sensor would keep the car from starting. But I'm wondering about the Park/Neutral switch. Can anyone tell me what this code means? And/or what the park/neutral switch is and if thats what could be keeping it from starting? BTW, the car is a 5 speed. The battery is fine and the alternator is as well, I think. I did not check for fuel pressure, but I'm hoping its a broken fuel pump. However, there is a very real possibility it is a broken timing chain. If the chain had broken, would I have gotten a code for that? What does a KA with a broken timing chain sound like when you attempt to start it? The car was towed to the dealership (Harrisonburg Nissan) which I hate to do (Dealership = Stealership when it comes to maintaince) and I'm hoping to get a call in the morning with an answer. Anyway, any help would be greatly appreciated.

TIATim

[nismofan14]

Well first if the timing chain broke, you have serious problems. Since it would have broke when you were driving, you can consider the motor ******. As for the codes, the way you read them are for a OBDI ecu, I am pretty sure your car has OBDII, someone correct me if i am wrong. So the codes would be 0303, Front O2 sensor circut. This does include a faulty front O2 sensor, along with injectors, fuel pressure, air intake leaks, and the wiring. 1003 is the park neutral/ switch. For the fuel pump, when you turn the key to the on position (w/o starting it) can you hear the pump buzzing? You should be able to. I would change the fuel filter also, unless you have changed it recently.

[TimzSE]

Yes, as a poor college kid taking 18 hours I would be perma-****ed. The way I read the codes was to pull the ECU from the firewall, turn the diagnostic screw fully clockwise, wait two seconds, then return it to fully counter-clockwise. This caused the CEL light to begin flashing in a series of long and short flashes. These were the directions I received from the 240sx.org faq. And I interpreted them as a 33 and 103. Was that not correct?

I don't really understand how it could have broken while I was driving? I had driven the car the night before and had not had a single problem. I pulled into the parking spot and put it in neutral before shutting it off to close my sunroof and it idled fine before I shut it off, leaving the car in second gear. Could the chain have snapped during my starting attempt the next morning? If so, and the KA being an interference type engine, would I still have bent valves and hurt other components despite the car never actually being turned on?

No, I do not remember hearing the pump buzz with the key in the on positiong, although I did not specifically listen for it. Secondly, I purchased a 300zx fuel filter for the car, but I have not yet put it in. Do you think a clogged or old filter could keep the car from getting fuel? And this may be a stretch, but what about a clogged cat. converter? Could that keep the car from starting?

Thanks for your help.

[bruinbear714]

Open up the valve cover and do a quick inspection to see if your timing chain is still in place.

If it isn't then DO NOT attempt to start the car or crank it.

Also, if the park/neutral switch is missing or defective, the car would not start up because that switch tells the ECU that the car is not in gear and that it is okay for it to start the engine.

[TimzSE]

Well it appears the timing chain is not, I repeat *not* broken. What seems to have happened is that the Bosch platinum plugs I put in about 300 miles ago are BAD! And that Bosch ($4 each) rates their plugs at heat ranges different from the OEM NGK's. Meaning that there is not an industry standard and the local yokel "Garrisonville Auto Parts" thought that the same numbers on each box meant they were the same heat range. God only knows what car these dumb *** plugs are for! So the plugs fouled my engine with tons of carbon build-up in the intake plenum and throttle chamber. Yuck. And to think I couldn't figure out why my gas gauge was broken and I was only getting 150 miles per tank. ***ForeHeadSlap*** Anyway, I'm going in there in a few minutes to take a look at things and make sure these guys aren't trying to bilk my out-of-town *** with the typical harrisonburg we-hate-jmu-students-but-love-their-money attitude. Instead of the ugly $2K bill this might end up *only* costing me 300 bucks or so. Meh, whatever. Anyway, the reason my car wouldn't start (well, ANOTHER reason) is because the flooded engine probably sent my engine into a fail-safe mode causing my fuel pump to shut down. So I don't think thats broken either.