1992 won't start, no spark.....

[levi_elston]

Background:
I've been having some coolant loss issues, and the burnoff smell associated with it. I also just bought a radar detector a couple days ago and wanted to wire that in and not use the cigarette lighter (didn't work anyways). Well, today I was driving it over to my father's garage to work on these two item and noticed that after about 10 minutes of driving or so, it would miss if i tried to accelerate (not even hard, just slow accel). A couple weeks ago i noticed the same problem, and didn't understand it and i went back to drive it the next day and it was fine, and haven't had the problem since. So anyways, it was weird that it was missing, but still running, so i shut if off, let it sit for a little bit and started it back up and it was still doing it.

Problem:
Having said all that I wired in my radar detector with no trouble, turned on the key (didn't start engine, didn't think there would be a problem) and it worked fine. Then i proceeded to degrease the engine with engine bright hoping to be able to get a better understanding for where the coolant leak was coming from. After applying the enginebright i used a pressure washer to blow the grease off keeping the water away from electrical and alternator as best as i could. After letting it dry for half an hour i tried to start the engine and all it would do is crank over and over, but wouldn't start. So i started checking loose wires (perhaps from the pressure washer) and checking fuses (cause i was messing around the fuse block when wiring the radar detector) and everything seemed fine, even checked the plug wires. Nothing! So i pulled a plug wire off and put a plug in it and held it to the exhaust manifold and cranked the engine, but no spark! Thought maybe the coil got wet and was preventing it from starting somehow? So i let it dry for about 2 more hours and it still would only just crank over, but never start! I'm extremely frustrated and need some help! From one vette owner to another, HELP ME PLEASE........

Levi

 

[Vettefan87]

If your 92 has opti spark (I dont know since i have a 87) I would imagine that you got it wet after you powerwashed it and toasted it. its generally not a good idea to power wash any type of motor or soak an engine with anything for that matter. Someone will chime in that knows more about it then me.

 

[firedawg]

'92 was the first year of the Opti, it sounds like that may be what the problem is, they don't like water! Especially the old ones ('92-'94) It is located just under the water pump at the front of the engine. Definately may want to check that out. Good Luck! :eek

 

[levi_elston]

how can i be sure that this is the problem? i don't have a code scanner, so how can i be sure that this opti is whats wrong before i drop a bunch of money into it..... also, where can i get a replacement?

 

[levi_elston]

just went out to restart it this morning and it started, apparently it dried out enough to start, but one of the cylinders is still missing...... any ideas why? is there something else that could be wrong with the optispark? what other stuff can i check to perhaps fix the problem without replacing the opti?

 

[WhalePirot]

You DID remember to reinstall that plug wire, right? (the voice of experience)

If so, did you damage the wire while pulling it? Does the offending cylinder have spark?

Some here know, that I get a lot of info from 'reading' plugs. Fouled ones, and/or the colors, etc. tell volumes about what is wrong.

Given the recent history, though, ignition issues seem to be the proper path. Perhaps more detail about your mileage and such will help us more.

 

[firedawg]

levi,
There are some great articles in the tech center here at CAC. I have found some that may help you out (they are below). If you get a code 16 during an engine scan, that will be the opti.

The opti's prior to '94 were non vented, meaning they could not drain any water or moisture from the unit since it was sealed, there is a kit available from Mid America Designs that lets you add a vent. I hope this helps you out some!!! I'm dreading the day I start having opti trouble as I still have the original in my 'vette too. Once again, best of luck

1992 ECM Codes
1992 Opti Service Bulletin
GM service bulletin
Mid America Designs Opti

Thread with alot of opti spark links (Very informative)

 

[levi_elston]

i checked cylinder 2, 4, 6, 8 (because i couldn't check the other side cause of too much stuff in the way) and 2 seemed to be arcing down inside the plug, not on the tip, so i replace the plugs on 2, 4, 6, and 8 and still same trouble, actually worse! after i changed them i went for a drive and it seemed to be running fine, a little bit of missing at low rpms, but not too bad, so i took it back in and went to leave like an hour later and it got really bad, bad enough that it pops like mad out the exhaust, not sure if its backfire or what, but it a popping noise that at first only at low rpms revving up to high rpms, but now it just pops all the time, like maybe once every couple or three seconds...... (at idle)... so i parked it and am giving up for today, i'm completely stumped, i hope its not the opti! that thing just looks like a major pain to change, and right now i don't think i have the patience for it....

i've only owned the car for about 3 months, its got approx 82,000 on it and up till now, i have not had to do anything other than change the oil, and i don't have any other service records from the previous owner..... not even an owner's manual!

also, i have noticed it doing it only on warm days, the one time a couple weeks ago was like 80, and yesterday and today its been over 80 and sunny (aka, shouldn't be humidity troubles)

thanks a lot guys, i really appreciate any past and especially future suggestions!

 

[firedawg]

Stumped as well

Besides the Opti, I don't know what it could be (Not saying it's not something else) I'm not a mechanic, so I'm stumped as well. What I know, I've learned between here and messing around with the car myself, I know a little about the Opti because I have been watching mine, doesn't have alot of miles, but it's 11 years old and that would be my luck! Checking the codes always seems to be a good place to start though when you're stumped, hopefully it'll give you an idea where to start.

I know what you're talking about with the plugs, they're a pain to do anything with, I took my vette over to MadMic and had the guys at his shop do my tune-up.

 

[levi_elston]

i can go along with the opti being the culprit here, especially since it can be intermittent and is worse when its warm out, but the exhaust popping noise has really got me confused...... i've never heard a car pop like that before, and its kind of a weak pop, still very easily heard, but not like a bang from like a lawnmower backfiring.... the only thing i can think of is backfire, but it doesn't seem hardly loud enough to be that, any other suggestions as to what it might be?

also, is there a cheap way to check codes (if i don't have a code scanner, and can't drive to auto zone)

 

[levi_elston]

first off, i appreciate all of your opinions, but everyone is saying that
its probably the opti, is there any way to be sure other than replace it and
see if its better?

also, should i replace with a stock one, or get a vented one or a dynatech,
or go with a 4 coil electronic from delteq? thanks again for you help....

 

[WhalePirot]

'Throwing parts' at any problem is an expensive answer. I'll start out by saying that I don't own an Opti car and my newest manual is for '90. Throwing hi-perf parts at a problem, w/o knowing if the root problem is fixed, is pricier.

You must have a great ignition shop in the Dayton area. If no one chimes in here, with a recommendation, check with you local Vette clubs. the best I have found here, is Ted, at Orange County Speed.

At 80,000+, your engine likely needs new wires. You can check their resistance with an ohmmeter (all should be close in value, given the differing lengths), but they might suffer from breakdwon in the insulation. I'd look for arcing (soft, blue, electrical flashes) at the wires, in a darkened environment, with the engine running, if you want to spend some time on it. Decent wires need not be expensive, nor are standard plugs. Multi tipped or platinum plugs are mostly hype (c'mon flamers). New plugs and wires might be a good place to start.

While those plugs are out, make a simple holder, with each plug inserted in a numbered hole, corresponding to cylinder number. 'Read' them yourself or take them to a no-BS mechanic for analysis. They will tell you LOTS about how each hole is running. Links to web sites with info on reading plugs is elsewhere on the forum.

Old plugs build up carbon, ideally tan colored, on the ceramic, which draws current from the desired spark we need to ignite the mixture and give a good flame. Expensive and exotic plugs, wires or ignition boxes will not change this at all. Keeping the proper (and probably stock) plug, of whatever brand floats your boat and having good wires (nothing wrong with the Delcos we got with the car) will save you cash and deliver all the performance available from your engine. Ultra high revving and boosted engines MAY change the components demanded, but most of the engines discussed on this forum, including my 406, run just fine with the stock HEI, good wires and standard plugs.

 

[Skant]

The problems you've described and the things you did that arrived there are the archtypical death of an optispark.

To start with... you have a coolant leak problem. And then the engine starts missing. Typical. Coolant leaks typically come from the water pump... which is located directly over the opti. If the water pump leaks, the opti will get soaked and wrecked. Another common tell tale for this is a horizontal spray pattern on the inside of the hood just above the front of the engine... this comes from the fluid making it all the way down to the harmonic balancer and the serpentine belt and then being flung.

Then you power washed the engine and the car wouldn't start at all with no spark and it wouldn't start again until much later after it had dried. You just filled the optispark unit with water. Sorry. After it dries out, it will work again... but it will corrode and the operation will get worse and worse. (That it got worse after you changed some of the spark plugs is probably just coincidence... it will continue to worsen whether you do anything like that or not)

My friend... the chances that your optispark unit is not wrecked are slim to none.

If you want to verify that the problem is the optispark, you will need a diagnostic reader that can talk to the computer. However, in this case, I think can just safely change the optispark without fear that you're fixing the wrong thing. You're wondering how a bad opti creates all of the symptoms you've mentioned? It's not just a distrubutor. It's also an optical positioning sensor. The computer uses it to determine the position of the crank shaft (and it's very good at this! Which is why it was a revolutionary system). So if the optispark isn't working, the computer will have no idea where to even begin with the spark timing. It doesn't even know which cylinder to fire! And fuel delivery is screwed as well along with everything else.

Now... before you fix the optispark... fix the coolant leak! Or it will just kill your new optispark again within days. That typically means replacing the water pump, but that diagnosis isn't so certain. Also check the side pods on your radiator.. that's another common leak area.. however, that one doesn't usually kill the opti.

Never wash your LT1 engine with running water. Only do it by hand with a bottle of simple green. Do not spray the simple green on the corvette emblems on your fuel rail covers.. it will take them off (cosmetic damage only).

Beyond the optispark, there are other things under the hood you can kill by powerwashing the engine with degreaser. In particular, degreaser can take the laminate coating off of your suspension monoleaf spring. If this happens, it will start fraying into individual strands, and the front of your vette will start dropping down lower and lower. So check your springs over the next few months.

And never power wash under your hood again! That's a big no no! :nono As you can see, you can really screw up the car in expensive ways with that hose!

Hope this helps. Sorry that this has happened. This particular problem is the LT1 vette's achilles heel. You really need to be aware of this particular vulnerability and protect your vette from it as best you can. As long as the optispark doesn't get wet, it works great. Reliable and will last a long time if it stays dry. But it's vulnerable.

- Skant

 

[levi_elston]

is there a possibility that i can just take off the corrosion and dry it out real good, then put some vent hoses (saw at a website posted from above) into another vacuum line from those 3 holes at the bottom of the opti? is it worth messing with or is it just a waste of time (saw it at this website http://www.corvettefever.com/howto/16758/ except they put an inlet from the air intake and an outlet to get full air drying flow though the opti, where i was just thinking about a vacuum line) has anyone done this or have any suggestions with it, i think i'm gonna try it....

thanks again, all the help is extremely appreciated!!!!!

 

[Vettelt193]

The venting is worth it on a new opti, but after 80k miles, the current opti is probably already a done deal anyway, they naturally wear out and are really only good for 100k in the best of conditions.

Feel under the water pump (there is no pulley on it, it is just below the throttle body) there is a small hole under it, and i would put money on it that coolant is coming out there... that drips on the opti and fries it (like skant said earlier). The timing on your car is so advanced now (because the opti is confused) that you are getting popping. the hotter your engine gets, the worse it will be. This is dangerous for your engine, you could really screw something up if you keep running the car this way!

you really need change the opti and water-pump on your car. You can vent the new opti if you want to, it will help make it last longer.... If you only change the opti, and not the pump (and the pump is leaking) you can kiss your new opti goodbye in only a short period of time too.

On the bright side, once it is changed, no big maintenance should be necessary for many miles.
On the down side, changing the opti is a real PITA... On my '93, i had the whole car apart, and couldn't get 1 bolt off because it was corroded in place. i wound up paying to have the car towed to a shop to pay the shop to do the job. Needless to say, that repair cost almost a grand... new opti, new plugs, new waterpump, towing, labor, etc.

 

[levi_elston]

thanks for the help guys, i'm gonna attempt to fix it over the weekend, i'll let ya know how it goes.....

 

[lancewest]

won't start....

Posted a problem last night....I'm a couple of days ahead of you. Replaced the water pump and optispark. Now the car cranks, but won't catch for some reason...checked the wiring sequence & its OK. So I'm really having a tough time figuring out the next thing to do...Good Luck with yours.

 

[levi_elston]

well, took out the opti and cleaned it up, cleaned off rotor and contacts, sealed it back up and put it back on and it runs great (oh yeah, replaced water pump, it went bad) i also replaced plugs and plug wires, so i got away for about $200 instead of like $1000 (which is kinda what i've been hearing)

here are some pictures of just how dirty the thing was, and of how bad the water pump looks

 

[Skant]

Glad to hear it's working. Don't think I remember hearing of anyone successfully cleaning and getting more mileage out of a wrecked optispark. I think we'll all be curious to hear how long it lasts after this repair.

- Skant

 

[lancewest]

Won't start?

Posted a problem last night....I'm a couple of days ahead of you. Replaced the water pump and optispark. Now the car cranks, but won't catch for some reason...checked the wiring sequence & its OK. So I'm really having a tough time figuring out the next thing to do...Good Luck with yours.

Murphy's Law....The problem is always in the last place you look...in my case the computer chip module somehow burnt up causing my problems.

Hope yours is solved.