Opti woes and replacement options

[turbostar]

don't know what happened to the old site,but found my way over here. Hope others came along and that we'll get the news from buickwagon about his new opti after he took it apart.

 

[buickwagon]

Found my way back. I wasn't actually lost, we lost my grandmother. Sorry for the delay, but her funeral today took precedence over the opti.

Anyway, short answer:

1. The new Delphi brand optispark distributor I bought from RA does indeed include a Mitsubishi sensor.
2. The new Standard Motor Products brand cap and rotor were made in the same factory as the Delphi ones on my new distributor.

Long answer with photos:

Label on box:

Back:

Cap:

Inside. Look close: those are aluminium terminals on the cap:

Sensor and disk. Close examination under a 10x jeweler's loupe convinced me this is a new sensor, not something scavenged from a core. The Mitsubishi symbol can be clearly seen beside the "J520":

SMP premium cap. Note the brass terminals. Unfortunately, there's some sort of hardened drips of epoxy hanging off the plastic in places. Especially the upper right spark plug wire connector:

10x magnification with a jeweler's loupe revealed they were the result of splashed epoxy from filling the front of the cap. The splashes ran down around and formed drips. The epoxy was very hard, but did chip off the plastic cleanly.

Both caps side by each.I'm sure these came out of the same mold, down to the "A" and the injection marks. Two differences: Look carefully between the two terminals near the lower right spark plug wire connectors. There is the negative of a torx-head screw and the thin outline of a tab that was screwed to the mold on each. However, the tab on the left imprinted SMP's "Standard" logo. The tab on the Delphi cap was left blank. (The same difference can be seen on the white seal/separator plates.) The other difference is that both caps were imprinted by dot-matrix impact engraving with some sort of batch or serial number after they were cast. The two numbers were different. (The aluminium casting of the Delphi distributor body was similarly imprinted)

The rotors do not have the tab and are absolutely identical. BTW: the Delphi rotor screws were loctited from the factory. The SMP cap/rotor kit came with new screws for the cap and rotor plus new o-rings for the shaft and decent instructions. I greatly prefer the brass terminals so I'm going to use that and would not hesitate to recommend it as an alternative replacement over anything with aluminium terminals. The Delphi cap will become a spare which I will probably lose before I ever need it. Note that SMP also offers a cheaper cap, with aluminium contacts. It may be identical to the Delphi, but I have no experience with that version.

 

[turbostar]

Buickwagon,sorry for your loss,and thanks for a great report. From what you have said,I conclude the Delphi opti is worth buying when needing a new one-it has the right sensor and the sensor is new. Also sounds like it is well made. Is this your conclusion also?

 

[buickwagon]

I would be happier if it came with the brass terminal cap, but yeah, from what I have seen and read I would (and did) take this over an aftermarket unit primarily because it does indeed have a genuine Mitsubishi sensor, and that seems to be the most critical component and most likely thing to fail in an aftermarket unit.

 

[buickwagon]

Got the new opti in today, and found out why the old one was losing the high resolution signal -- dang thing was coated with oil inside. The high-res slots are so fine they were coated over with oil so the sensor didn't have a chance of shining light through the slots. I think it'll be a good spare once it's all cleaned up again. Hopefully the new seals will prevent any oil from immigrating to the inside of my new one.

I must say I have greater sympathy with those that replaced the mechanical fan with an electric. And what epsilon-minus semi-moron decided to put one of the air pump bracket bolts behind the opti? It's a stupid catch-22: To take the air pump off, first remove the opti, to remove the opti, first remove the water pump, to remove the waterpump, first remove the air pump...

 

[buickwagon]

I got a PM from someone asking:

I am curious if you have a minute if you could briefly tell me how to replace opti I will be doing waterpump and it together in a couple of weeks. I would appreciate the help so i can do it myself shops here in xxxxx are just trying to gouge money and still look at my engine in pure confusion. other quetions are would i need a new ICM? Is it possible since at this time I do not leak oil do i need just cap and rotor? Any wire and plug preferences?

I am answering here because I think forums should be all about public discussion/debate/education and if I make a mistake, someone else can jump in with the correct answer or suggest alternatives I may have missed:

There are a great number of tutorials on you-tube and various forums detailing the procedure with photos and video. The Buick varies only in that it may have the mechanical fan to complicate matters (tow pack cars with HD cooling option). But in short, here it is (assuming mechanical fan):

drain the radiator
remove home plate
Unclip sensor wire and vacuum tube from air intake elbow
remove air intake elbow from MAF and TB.
remove fan shroud.
unbolt fan and remove
slack off adjuster and remove fan belt, fan pulley
unbolt 3 long waterpump bolts that also secure fanbelt adjuster bracket.
remove bracket complete with adjuster.
remove nut from waterpump stud securing the air pump bracket.
remove 3 bolts that secure air pump to bracket
disconnect air pump hoses from air box and pipe.
Disconnect wires from bottom of air pump
remove air pump
slack off accessory belt adjuster and release belt from alternator (note: you don't have to remove this belt completely, just get it loose)
disconnect temperature sensor wire from waterpump
disconnect 2 large and 2 heater hoses from waterpump
remove remaining 2 bolts from waterpump
remove waterpump.
remove waterpump spline drive coupler before you lose it.
remove 3 small diameter bolts from harmonic balancer.
Dislodge stamped metal fan pulley. NOTE: it's a press fit. You may need to go below the car and hit the hell out of it with a block of wood. Personally, I heated the hub up a bit with an Oxy-acetylene torch and tapped it off from above.
Remove the 3 large diameter bolts from harmonic balancer.
Remove harmonic balancer.

NOTE: 3 easy words. Again: press fit. If you do not have the mechanical fan then you may or may not have the three 3/8" tapped holes that the stamped fan belt pulley was bolted to. If you do, then you can use a conventional puller to remove the balancer from the hub. If you don't, then you can choose to get underneath the car with a piece of 2x4 and a big hammer or you can choose to remove the balancer complete with the hub with a puller. If you go that route, then you need to remove the centre bolt from the hub, remove the thick washer, reinstall the bolt 4 or 5 turns into the crankshaft for the puller to push against. You will need a puller with three 7/16" NCT bolts, that thread into the holes where the large bolts where. The puller should have a flat centre. If it's pointed, then touch the centre of the factory bolt head with a drill bit to make a dimple to keep the point centred.

Also, if you have a 96, there may be some extra steps at this point. The 96 has a crankshaft position sensor in there somewhere. I don't so I don't know what extra steps are involved there.

You will need a strap wrench large enough to wrap around the harmonic balancer to keep the engine from rotating while you draw it off. It will gradually get easier and easier and then suddenly harder when it hits the bolt inside. STOP. You now have enough room to remove the Opti. Continue only if you are changing the seal. Remove the puller and retaining bolt. You may have to tap gently with a hammer or find a long 3/8" bolt to finish the job. The 3/8" bolt won't thread into the crankshaft (it's tapped 7/16" NFT)

If you remove the hub, you should replace the seal. If you replace that seal, you may as well do the others too. You will need a special protector to install the infamous waterpump drive seal over the splined shaft. You will need a seal puller to remove the opti drive and crankshaft seals. The seals and waterpump gaskets all come in the Felpro timing cover gasket kit for $9 from Rock Auto. They might not leak today, but it is a lot of work to get to this stage again in the future if they should start seeping next week. OTOH: if you have never replaced seals before, these large diameter ones are probably not the best learning tool. Your call. Anyway: where were we? Oh yeah...

unplug the opti sensor connector.
unplug the opti coil wire
unplug the 4 ignition wires on each side
remove the 2 rubber vent lines from the cap and the body
unbolt the opti 3 mounting bolts
remove opti complete with cap.

NOTE: if you are just changing the cap and rotor, it might be possible to do that in situ. But it's a lot easier on the work bench. There's tiny screws and loose plates sandwiched together, and it's all horizontal at arm's length -- a recipe for disaster, IMHO.

Reassembly is the reverse of the above. Lubricate all seal lips with oil. Be very careful to orient the opti pin drive correctly. I rotated the engine with the crank (install hub bolt to turn crank) until the pin was at 12 o'clock as the easiest method of pre-setting the opti end of the coupling. The pin engages the larger square hole in the opti.

You will draw the hub back on to the crank with the factory bolt -- start without the washer to ensure maximum thread engagement at the start. 1/2 way or so remove the bolt and install the thick washer. Unless you have a 96, it is not keyed in place. On OBD I cars, the optispark takes care of all timing issues so there's no need to orient the harmonic balancer to a specific position.

At this point, you can temporarily reinstall the intake plumbing, reconnect all sensors (including the coolant temperature sensor) and start the car to verify all is OK. Don't run it long without the waterpump and coolant, but you can start it.

Don't forget to install the waterpump drive coupler when you get to that stage. Clean the old gasket material off both the block and the pump and install new gaskets. I used a bit of smurf snot (aka ultra-blue RTV) to help hold the gaskets to the waterpump for assembly, as well as pre-installing the top bolt on each side to keep the gasket in position. If the waterpump doesn't want to slide all the way in place, you may need to turn the coupler slightly to engage the splines.

If your opti is not throwing codes and you are not leaking oil and your vacuum vent system hoses are in good shape, then yeah, a cap and rotor are probably all you need. The ICM is separate from the opti, and a hell of a lot easier to get at! For plugs, everyone seems to recommend the NGK TR55IX for the LT1, and I like iridium plugs. For wires, don't cheap out, get decent ones. EG: SMP Pro series, not economy series.

And now a quick comment about "gouging" by repair shops:

As you can see from above, changing the opti is not as simple as with a traditional distributor. When pricing a job, the shop usually looks up the time required from a standardized listing. Given the age of the car, they may add a bit extra to account for unexpected things like rusty bolts. Then they multiply that by their shop rate. I personally have saved hundreds of dollars over the years by purchasing thousands of dollars in tools. A shop spreads the cost of tools amongst many customers, but the cost is there. So is the cost of labour, taxes, heat, hydro, etc. etc. etc. I mention I used a torch at one point -- I just filled the O2 cylinder the other day, it was $75. Acetylene is even more expensive. I mention the special tool to protect the waterpump seal from the splines -- Kent-Moore J-39087 Front Cover Seal Protector. List price $58, eBay prices are around $25 to $35. Buffman occasionally has these available for around $10. I have a small machine shop in the corner of the garage and made my own out of 50¢ worth of material (and about $10k worth of tools). Some people have carved up Sharpie markers or used sockets with mixed success.

To my way of thinking, a good shop earns their money. The price is fair for the value received and reflects their overall expenses and a reasonable return on that investment. It may be more than I want (or have) to spend, but that's a choice I have to make. I consider it "gouging" only when the shop does a poor job, talks the customer into unnecessary work, charges for work not done or is obviously trying to charge way more than the market rate.

But that's just my 2¢

 

[shagginwagon]

I love how he asks if you have "a brief minute to tell him how to replace an Opti" lol.... Thats a pretty good break down, thanks for taking the time.... I don't know if it has been mentioned, but I read awhile ago about getting an "unvented Opti" which supposedly helped in fixing of some of the bugs of the original version. Does anyone know anything about that?

 

[buickwagon]

The original Chev opti was the unvented one and had all sorts of problems with corrosion. Getting the original "unvented" opti wet was a death sentence.

All B bodies got the revised "vented" opti (I read somewhere that it was redesigned by Buick for 94. It didn't make it to the Vette, Camaro, etc. until 95). It is vented, but it's a closed-loop venting system. A small hose runs from the air intake to supply clean filtered air (after the MAF, so the other side won't upset the calculations). The second hose provides vacuum, via a restricted orifice and a check valve. The cap is sealed to the separator plate and the separator plate to the distributor body. Also, the low tension / sensor wires have a rubber weather seal where they penetrate the cap. So long as the seal holds and the vent hoses remain intact and nothing gets plugged, a constant tiny vacuum prevents the accumulation of moisture inside the system.

The original has a different drive mechanism and therefore a different timing cover. To switch to the older style might be possible, but would require the necessary parts. Or you could just disconnect the vent hoses, which would pretty much accomplish the same thing: you would shorten the lifespan of your opti.

There is a TSB describing a spark issue if the opti supply air tube becomes plugged. Full engine vacuum will build up in the cap, sucking the cap inwards and causing misfiring. The cure is to repair/replace the vent harness. In my case, I did experience this. The supply hose had become soft and collapsed. Following some advice I found on the internet, I blew out the opti with compressed air when repairing the hose. Yes, it did make a difference: the misfire went away and all was right with the world for a while. However, the compressed air also blew out one or both of the o-ring cap seals, allowing oil from the timing cover seal leak to get sucked into the opti, coat the sensor wheel and start causing high-resolution sensor failures. So I'm not really sure the compressed air idea was a good one. At the very least, I used too much pressure.

When I installed the new opti, I backed up the o-ring seals with a thin layer of smurf snot -- just in case.

NOTE: lookiing at my description again, I stated "lubricate all 3 seals". Since I wrote that, it has come to light that the opti drive seal is a teflon seal (at least, in the Felpro timing cover gasket kit). Teflon seals should be installed dry or they may start leaking. So, lubricate the waterpump seal, lubricate the crankshaft seal, but do NOT lubricate the opti drive seal.

 

[Buffman]

just FYI there's a 4 part series on youtube for opti replacement..
http://www.youtube.com/watch?v=WwDuoebEAJE&list=PLBE078B7F8994EE85