Okay, let me have it, but go easy on me. . . this is my first post and my first 'Vette. Well, actually I bought it for my wife but if I don't get it running again it WILL be mine. . .

I've searched the forum for engine washing issues, of course AFTER the fact of my washing it, what I thought was fairly carefully (no pressure washer, etc). I tried to stay away from electrical parts and the engine was running when I rinsed it off. It was supposed to be easy. Right????

Yes, I've read about the "opti-spark"/distributor, and it sounds like this might be the issue as the engine was running a bit rough (missed once or twice) during the rinse. Then after rinse, drove it around the block and it was missing like a banshee, like it was only firing on 4 cylinders.

I let it idle a bit more (5 minutes), turned it off to wash the exterior, now the C4, '93 won't even start!!!!! My wife is going to kill me now. . .

First: Is this opti-spark some drunk engineer's idea of "cool" or stupid??

Second: How do I attempt to dry out the "distributor"/opti-spark?

I remember in my days with muscle cars we'd just yank the distributor, wipe it dry, and drive around the block. Obviously this particular year wants to hassle me with trying to surpirse the wife with a clean engine (and yes, SOME women DO care to see a clean engine). I was wondering why it was so dirty when we bought it a few weeks ago--the rest of the vehicle was cherry.

So is this the ONLY potential issue (damp/wet optispark)? Or might there be other "gotchas"?

Help!!!! Clue me in, but again, go easy. . . Thanks in advance to any useful advice (other than "Don't wash the engine!" )

 

You will end up removing the cap to check it out. This requires removing the water pump first. There are some odd size little torx bolts that hold the cap on.

 

I would guess replace opti you are not the first to do this washing down the motor there should be a disclaimer under the clam shell

 

http://www.mamotorworks.com/corvette?frame=3.804

"replace your Opti-Spark every 60,000 miles"

If the opti is toast....you may as well clean/hose the rest of the engine before installing a "new" opti.

 

I was in a really bad rain storm a month ago and my opti got wet. Car ran like crap and didn't want to start after I shut it down. I put a fan on engine overnight and it fired up the next day. It still ran rough but eventually dried out and is working fine now. If you damaged the opti you may as well try everything else before you have to pull the water pump and then the cap.

Dave

 

This is great stuff ya all, and a very quick response too. Thank you all for that. Again though, I'm still wondering if this optispark/distributor is the only problem after an engine wash.

This opti-spark design leaves me with a sour taste for this C4 series--I only see a design to keep the service bays at Chevrolet full. The comment from "L71Maynard" sounds more common now the more I'm reading on this--a rainy day could put you out!!! Absurd design specs indeed!!!!! But does give me hope that it just MIGHT dry out on its own, but to what level of damage or corrosion????

Some followup questions:

1. Does getting the unit "wet" just fry the 'opti' unit?
2. Is it a for sure thing that one has to replace it?
3. WHEN do you know it has to be replaced?

Thanks 'engle1147' for that link! It shows the "recommendation" and the price as $300. The one comment of "...replace every 60,000 miles..." is frightening, from that link it sounds as if this is an actual Chevy recommendation?????

Having an aircraft maintenance background, it was NOT uncommon to replace something that functioned perfectly or even met specs as new. So I'm giving that comment as a 'lesson learned' from 'engle1147' (on replacing @ 60K) some thought as there is 97K miles on this 93/C4.

Where might be some other parts outlets to acquire best-bang-for-the-buck parts (quality/price of course)?? The one earlier from engle1147 seems to be pretty decent.

So any other thoughts other than the 'opti' is wet? Here's what I've recapped from the other comments thus far:

1. Hold off on replacing for now
2. Easiest--put a fan on it overnight to attempt to keep air moving over it
3. More difficult/time consuming--remove water pump to get to 'opti', torx bolts run amok to remove cap, dry out, reverse order to assemble.
4. Last resort--R&R optispark unit for $300 (minimum), but possibly do a preventative R&R on the water pump as well????

Anyone else can still chime in. . .I need all the help I can get.
This forum is GREAT!!! Thanks again to all thus far for such a quick response. You guys are excellent!!!!

Jesse

 

You could remove the cap and dry it out with compressed air. Put the cap back on and fire it up for 10 or 15 secs and see how it runs before you put it all back together or replace the opti.

 

Just thinking out loud - if you have a vented opti (94-96), maybe it would be possible to blow compressed air through the opti's fresh air intake hose and disconnect the vacuum line to let the air escape? I don't know if anyone has tried that, but if it sounds feasible, it would be a lot easier than tearing the front of the engine apart.

Also, if you wind up having to replace the opti and are interested in an MSD, I found the best price from epowershops.com when I bought mine.

 

I recently helped a friend replace his opti. Not a fun job. Had to hammer off the balancer and pull the water pump. We replaced the plug wires while in there. Even that was a chore. Anyway, the best deal we found was on eBay from The Parts Ladi. It was an AC Delco Opti for $245 if I recall correctly.

 

whobub,

Since yours is a 93, and assuming it it the original Opti, it IS NOT the vented version (started in 95) (however, consider installing an 'vented' version IF you have to replace).

Oddly enough, having the engine running likely caused most of the problem -- as it's the cool-down vacume and the resultant sucking-in of moisture into the OPTI via its 3 vent-holes in the bottom.

Not sure (certainly not willing to try), but washing a cold engine and letting it completly dry before starting, might circumvent the problem.

Don't believe you can remove the 'cap' without removing the water-pump, so if going that far, would suggest just replacing the opti anyway (given the mileage).

The OPTI is both a standard distributor (i.e. rotor and cap distributing spark to the cylinders via spark-plug wires) AND an engine/ignition timing device via an 'optical' system.

Whereas moisture might cause 'arching' in the cap, it more often causes corrosion on the 'optical' system, which is when it really 'kills' an Opti.

Have you tried pulling your 'codes' to see if you have any of the classic Opti codes? If not, try that and report back on which codes are displayed.

If you do wind up doing the Opti, also consider: water pump (as they get tired by 100k), water-pump and distributor seals in the timing-chain cover (to prevent subsequent oil leak), spark-plug wires (as they're a pain, but with most things apart, not bad), and maybe timing chain and intake manifold gaskets (if they have already started to leak).

Also, match-mark and be gentle at removing the harmonic-balancer -- it has a rubber seal which can be damaged if the outer edge is pounded during removal.

Lastly, after re-assembly, most start the engine before installing the water pump to make sure the distributor is OK, and consider flushing the coolant system BEFORE disassembly to get rid of any anti-freeze which could dump on your new OPTI if a seal doesn't hold or during initial start-up.

Also, consider using only distilled water during your first start-up/test drive. This way, if any leaks, it's only water, which is much less damaging to the OPTI -- thereafter, drain the radiator (and shop-vac blow out the 'surge' tank/engine via the radiator drain) and then add the old-style 'green' (zylex) anti-freeze and top-off with distilled water.

 

Good suggestion 'admiral' -- I don't have the instrument to pull the codes, and I'm too cheap to pay the 1-hour minimum charge at the Chevy stealer to get them for me (could have bought a decent/half-assed coder reader, eh )

Back to code readers. . . maybe a different topic/thread, but any good brands and pricing for a decent one? I can't think of equipping myself with any Fluke-level expense at this time for such a simple job as reading the factory codes. A suggestion here would be appreciated.

Had I known, I might have first tried the 'wash cold engine and let dry' that is, had I read it anywhere BEFORE I started. That's not a bad suggestion. . . Who would have known at my rookie stage that the 'opti' sucks in water!!!! Now that just literally SUCKS doesn't it?

Thanks again to any and all "chimers" I truly appreciate any help on this. My rookie feet are indeed wet now, and that's not from over-spraying the engine

Jesse

 

If you're going to tear it apart, now would also be the time to replace the hoses and serpentine belt if needed. The opti tends to cause a lot of "as long as I'm in there" work, but it's generally worthwhile.

 

If you have to get another opti, you can get a MSD, or Dynaspark Opti.
Their 92-94 opti are vented.

Get a GM opti and you can modify it to vent like the 95-96.


Or you can buy the MSD cap and rotor kit, and they will mod your Opti to be vented.



If you vent your opti, it will eleminate the biggest problem with the opti and make it pretty dependable.

 

Excellent illustrations!!! Thanks James (assuming from "james93lt1"). . . But now a couple of other questions:

1. The "jury rigged" venting of the original/GM part--where are such instructions? Parts list?
2. How/where to buy ONLY the (MSD) cap part?
3. How do I keep this as cheap as possible?

Like many of us today, I have more time on my hands than money.

I love the input of "while you're replacing the opti. . ." -- I've calculated approximately $3000 of repairs IF the labor is free My angle is more of "If I spend $3K in one swoop, it'll be as a down payment on a new 'Vette" I mean with that "klunker kicker", I might be able to get the price of a fully loaded 2010 down to $75,000 On another note, if I'm tearing it apart THAT far, I'd be tempted do an engine overhaul and beef the H.P. while I'm at it

All kidding aside, I need to just get this damn thing started again. It was running FINE just minutes before washing that damn engine; it SHOULD be able to start and run without tearing the engine apart. As someone said in an earlier post, I'll probably find the 'disclaimer' underneath the water pump to warn of not washing the engine.

I've had a fan on the 'area' now for 18 hours, switching/alternating sides and angle of the air flow. At 6 hour intervals I've attempted starting--it WILL start but only stays running for short time (less than 1 minute). I'm fixin' to go give it another try, if for nothing else to "move" any moisture around from sitting on any one contact for an extended period of time.

I would LOVE not to do ANY of these fine recommendations, and may have no choice to at least disassemble down to opti/cap to fully "air out". But if water got IN, then it must have SOME way to get out. Right????? Albeit slowly but surely. . . but EVENTUALLY????

Discuss. . .

 

The opti's I have seen get wet didn't run again. That's my experiance with them. And that includes the vented ones.

 

1. There is a article here on how to do it, but I did not melt the cap. I used a dremel with a drill bit at high speed to drill the hole.
http://www.corvettefever.com/howto/16758/index.html

Parts:
4- 3/16X3/16x1/8 t-fitting
1- 3/16 Vacuum cap
Vacuum line
sealant
Used of new set of opti vent line.

2.MSD cap and rotor part number p/n 8481.

3. The cheapest way possible is to do the GM opti mod, Less than $10 in parts, and put a "want to buy" in the for sale section for some used opti Vent lines. This would be the cheapest way.

The mod is real fast to do, the curing of the sealent takes longer.

The hard part is taking the opti out. I will take a long time, the first time you do it. After you do it once, it's gets much faster.

Hopefully it will dry up and start back up, if not it wll be about $150 to $600 in parts, depending on what you decide on, plus labor. But if you do a good repair to it, you should not have any more problems with it.

Good luck.

 

A week after I got mine I had a puddle of green fluid on the floor under the car, checked the bottom of the water pump and sure enough, it was leaking. So I replaced the water pump and the opti even though it was working fine.

I used a GM opti, but if I had a pre-95, I probably would have gone with an MSD or a Dynaspark.

While I was in there, I also changed hoses, wires, plugs, belt and coolant, all together, I spent about $800. If I had it do do over, I would have connected a hose to the weep hole on the bottom of the water pump and directed any leakage away from the opti, perhaps into a transparent container so I could tell if the water pump was failing.

 

Oh no 'tip vette' !!!! Now I'm going to get killed!!!! No hope at ALL to dry out????? I just went back and tried to start again from my last post of a couple hours ago. No luck at all this time--wouldn't even start. I'm glad the battery is holding up so well--putting it on a trickle charge between "drying attampts".

Thanks James for the 'parts list' and link to article on self-venting. And 'skybolt' too for pushing me more toward the MSD. I like your design/suggestion of 'directing to a <separate collector> to see if any fluid does enter..."

I actually found the MSD part#8481 for $140 from an eBay store ("Speed Unlimited") and that's w/free shipping. Anyone have any BAD experiences with these folks?

As a sidebar. . .adding to this mix seems to be MSD's new part #8381, but careful here. (part #s could be transposed: 8341 <new> vs 8481 <legacy> , with the 8341 costing a whopping $500!!! But you can tweak your timing from up above +/- 5 degrees. Nice, but I need to keep this on the cheap as I said, but thought I'd add the other stuff I'm finding in my research project I've forced upon myself. Back to the topic at hand. . .

Now if I DO end up going with the GM part, can anyone tell me if I can order the '95-'96 part (vented) and bolt it straight onto my '93??? This might save the custom/jury-rigging and adding the "vents".

The "venting" sounds like the way to go, but there is no part # that I've found thus far that lists "vented" when you key in on parts for the 1993 LT1 5.7 engine.

Thanks again

 

Whobub,

BTW, if you don't have a FSM (factory service manual) yet, get one, it's worth its weight in gold..

First on pulling codes -- you don't need a scanner or tool (aside of one paper clip).

The beauty of Corvettes, is they have a built-in diagnostic system which can display virtually all the error codes on the dash (96's are a slight exception in that they cannot display the ECM/PCM codes, but can display all the other 'modules' codes).

Here's one of many available links to how: http://corvettebuyers.com/c4vettes/ecm.htm

Regarding your question about just buying a GM Vented version (95/96) and installing it on your 93 -- sorry, you can't do that...

Because whereas the 95/96 distributor 'cap' is transfereable (and part of one conversion approach), the metal back is not, as the engagement shaft through the timing chain cover is completely different.

Regarding the Ebay 'MSD' distributor -- it sounds too good to be true -- and you know what can happen when that happens...

Unfortunately, to acquire a 'vented' OPTI, choosing either to convert a GM version or to buy a MSD (or other brands) will still cost about the same (unless you try drilling the cap of the non-vented version to 'vent' it, which has met with mixed success).

Sanity check time --------

Keep in mind that your current 'non-vented' version has lasted nearly 100k miles and 16 years -- any chance you plan on keeping the car for that many more miles and years?

If not, then perhaps just choosing a GM non-vented OPTI is the best choice (from a reputable supplier -- e.g. Forum's sponsors, or ebay's partsladi (which has many forum members touting their parts quality).

 

Indeed, I plan on getting the Factory manual--just didn't think I'd have run into such a major pain washing a freakin' engine!!!!!

Good feedback on the codes--I'll check it out between 'start attempts'. Hopefully you can pull a code when it doesn't start????? Or does the self-contained diags assume you will have a running engine?

In all fairness to that eBay vendor I mentioned in earlier reply--they actually appear to be fairly legit: 25074 sales since 2/05 with 98.2% positive feedback. So might be a source for one or many of us--possibly good chance on quality/delivery. I'll check out the partsgal you referenced as well.

Leaning toward the MSD version IF (and only IF) I have to replace it. Bottom line is GM should be ashamed of this design!!!!!

Thanks again to all for any comments, past or future. . . Jesse