| RE:94-94 1/2 optispark? |
Subject: RE:94-94 1/2 optispark? by bogus on 2007/12/23 17:20:11 depending on the problems, I always suggest checking the coil wire first. It can chaffe against the waterpump and then start to ground out. It will act much like a bad opti... but it's not. The Gen I opti (1992-1994), does it have some issues, mostly due to a lack of proper ventilation. What happens is that water gets in, it floats around as a mist, causes shorts on the contacts, which leads to carbon tracing. The worse case is if antifreeze gets inside... that is super bad. There is no way to get around that... antifreeze eats oils. It gets inside and seeps into the sealed bearing. That will then eat the grease and the bearing is no longer lubed. The lack of lube then causes the bearing to wear down quicky. Once the bearing wears, the problem gets really bad - the drive shaft that supports the rotor - and the opti side - starts to wobble. And that leads to codes. As stated, this is called an Opti-Spark. The Opti - or optical - side is closer to the engine. It is susceptable to oil leaks from the engine and damage to the driveshaft. You see, the optical side is a disc about 2" round. It has 360 small holes on the outermost edge of the disc, within the middle of the ring are 4 holes of different sizes. The outer holes are for engine timing, the inner holes are for fuel timing. Once a code starts to occur, it could be for either the Hi-res - High Resolution, or timing - or lo-res - Low Resolution or fuel. H16 and/or H36 for pre-1996 cars, IIRC. I don't remember off hand which is which, but either is bad. The only other thing that can gen that code is a bad ECM or a harness problem. Don't let someone tell you a bad knock or O2 sensor will do it, cause it won't! The aforementioned bearing failures will cause opti codes, too. What happens is the shaft wobbles, the disc loses contact with reality and the optical sensor can't pick it up anymore. All that it means is that the engine controller has lost contact with the Opti... for whatever reason... if you get both codes, it could be that the harness is in really bad shape, but if that looks ok (and I have seen some corrode), it is more than likely the opti itself. Moisture is the biggest enemy of the optispark. If it was my car, and I lived in a high humidity/heavy rain area, I would seriously consider replacing the entire unit. Especially if the miles on the unit are over 60k miles. At that point, in that environment, the opti becomes a ticking time bomb. The wisest thing to do is to take your time, if you can be without the car, I would remove everything, inspect the old opti, and order parts accordingly. If when you spin the drive shaft, and you hear grinding and it doesn't spin easily, replace the entire component set, otherwise, cap/rotor would be ok. The reason I am suspect of the earlier version is the lack of positive pressure ventilation. The later units have that. You can, tho, retro-fit a vent kit that will do the same thing, perhaps not as eligantly, tho. The other reason is labour - the Opti is a tough nut to crack, and I don't wanna do it more than I have to. long term storage is also bad, because the moisture will just sit and rust up things inside... As an aside, my opti has been in for over 100k miles and hasn't thrown one code. I did replace the high-voltage with the LTCC conversion kit, it allows for the use of 8 LS1 style coils. Works great!!! looks goofy, but it works great. www.bailey-eng.com |
