electromdc

1994 coupe 6speed, 190k miles.
I had my upper radiator hose rupture and spray coolant all over under my hood. I replaced the hose and coolant, but I am worried about the ignition components. It drove home ok, but on the next day I noticed a slight stumble that occurs once every second or two at about 25mph. The rest of the time sounds/feels fine. I tried spritzing the plug wires with distilled water, then blowing it off with compressed air to remove residual coolant . I tried drying out the engine compartment with my leaf blower. The stumble remains, but isn't very noticeable. Do I go straight for the optispark? Or is there a better place to start? Will I hurt it by continuing driving it? Does the optispark usually continue to worsen after getting doused with coolant? Any help would be appreciated.

PatternDayTrader

Personally I would put some miles on it just to see if its going to clear up or get worse. If it does clear up, then great, if it gets worse then it will be easier to diagnose.

hcbph

If it was mine, I'd pull all the electrical connections in the affected area (including plug wires) and use a electrically safe water dispersant product in them to get any moisture out.

midlifecrisis1979

You could try laying permeable bags of water absorbent material on the affected areas. kind of like the way folks use rice to dry a wet cell phone although they say that cat litter works better, just make sure you don't spill any under the hood, don't want you to turn it into a rice burner

electromdc

I went to drive it this morning and it's stumbling more, all across the rpm range. I will try those suggestions to get rid of residual water. I will drive my truck today

billschroeder5842

Sorry- it sounds like you have your answer. Time to do some deep diagnosis and pin down the (probable) missing cylinder.

midlifecrisis1979

Agreed! If you lack the tools and knowledge its time to take it to your local trusty certified mechanic!

pacoW

how old is the opti?

billschroeder5842

Age is certainly a factor but I'm thinking the explosive hose with fluid everywhere did more for failure (if it failed) than mileage.

electromdc

I am at about 192k. I have owned it for a year, since 182k. Not sure how old the distributor is. I will tear it apart soon. Just trying to decide what distributor to order to have on hand. I have read that most people say only remanufactured with Mitsubishi sensor.

pcolt94

Get into a pitch dark area and run the engine and look for any sparking around the plugs and wires. Look especially well at the coil wire as it passes thru the water pump for any sparking. Do all this while revving the engine also.

Make sure the plug wires are all the way on the plugs.

You can also get a long thin screwdriver and attach a clip lead to it and ground it. Then go around the wires, coil wire and plugs and see if you can pull a spark. Use a small flashlight so you can see your way around while you set up and be careful not to stick the screwdriver in the serpentine belt.

KenMathisHD

If you're really concerned about the opti, you could scope it or have a shop scope it to see how it's working. If it's looking healthy, then you save yourself a little bit of trouble.

On the bright side, if it is the opti, then now is a great time to upgrade to a vented opti, replace your water pump, plugs, wires, belt, replace your front seal and timing cover gasket. You could also get some cleaner and scrub off any gunk you see below the engine, since you'll have a lot more room to move down there once the balancer and opti are out of the way.

electromdc

I apparently forgot to respond with the solution:

While swapping the opti (which looked fine) and the water pump (also fine) I decided to swap plugs and wires.

Root cause: one of the spark plug wires had been eaten through by a belt, likely pushed into harms way by the exploded radiator hose. I couldn't see it during initial disassembly. oh well. I only found it after the unit was swapped and I was running new plug wires.

TorchTarga94

Good to hear, and thank you for update. So its been fine for 1.5 years after repair?

electromdc

Yes it has been fine for 1.5years since.
I recently developed a fuel issue that I posted in another thread, but spark has been fine.