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Screwed something up, cleaned engine, runs like crap now HELP



I cleaned the engine with an engine cleaner and hosed it off, now my 94 Vette is running like crap, and some kind of smoke is coming from in between the engine and firewall on the passenger side. HELP!!

First Thing Don't Panic

I'm sure it isn't anything serious. However there are some precautions on cleaning your engine that I'm sure you are aware of. I've cleaned my engine several times at the car wash and kept the engine running while doing so. sometimes I dont get the cleaner off the exhaust and it smokes for several minutes and then evaporates. I'm not too familiar with 94's other then it is a beauty and congrats, by the way, on your new Vette. (read you previous post) I hope you get a better answer then what I gave and it isn't anything more then cleaner evaporation.

Joe V.
it seems to have stopped smoking I think. But it wont run. It will start....but when I put it in drive, it dies.
OK....it seems to be running ok now......I let it sit for several hours after letting it fast idle and get pretty warm. But, I still I want to know what I did to make it do that. Was is something with the fuel injectors or oxy sensor or what. The smoke was coming from in between the fire wall and engine on the passanger side? Is there something there that was causing the problems?. Any advise would help, so i dont do that again. The owners manual says when cleaning the engine, do not spray directly into the "V". What is the "V" on this year engine.

Meet Mr. Multispark


You have bumped into the weakest link of the LT-1 engine. As you have noticed, there is no distributor in the back of the engine by the firewall. That is because it is mounted on the timing chain cover behind the water pump.

It is critical that this area stay dry. Any moisture from an engine detail, or other source will tend to corrupt the multi spark unit. For those that have replaced it before (part alone is approx $400), they will tell you the same.

You may be okay, but it could continue to have problems until you at least buy a new rotor and cover. There are a pair of vacuum lines coming off the bottom of the unit. It uses engine vacuum to keep the area dry while the engine is running.

I don't know about calling it a V, but G.M. does not want you to get this wet.

The smoke was just water and cleaner steaming off. That model may have heat shields around the front CATS. Sometimes they steam until all the moister is out. No worry there.
Thanks Chris, seem you may be right. It has stopped "smoking" or steaming. I have drove the car now....but it dont seem to run like it did to me. I will take it in to the Vette Dr. here in houston and let them check it out. I think it needs the fuel filter changed and the fuel system checked anyway.

Sure is great to have you guys here for advise. I sure thought I had messed up something. Dern thing was spitting sputtering and stalling like an old Jalopy.

Is it possible to have messed up the fuel injector system or something. Like I said, its running out ok, just dont seem like it was before this happened. Or is it possible to have some moisture still in it?

whew, Glad to hear it's running.

It sounds like your back in business, I guess all the techs are on Vacation, it's a good thing Chris McDonald was able to shed some light on this. ALLS WELL THAT ENDS WELL.
Joe V.
Glad you posted this Riko....

I just picked up some engine cleaner myself, and was contemplating a little cleaning effort as well.

Should I be concerned with the same issue, or others while cleaning '78???

Engine running or not running while cleaning???


The fuel system can not be contaminated by the water through washing the engine. However, the ignition system may now require the removal and cleaning/replacing of the opti-spark to get it back to 100%. Yes, it will dry out, but the moisture will corrode the contact points.

Imagine what would happen if you took the dist. cap off your 74 and sprayed water straight inside. Then you put the cap back on and tried to start it. It you let it dry out it would eventually start, and sputter until it dried all the way out. That is exactly what has happened to your opti-spark unit. Hoever, it is not very easy to pull the cap off the opti-opti spark to help it dry out faster.

There is one thing you can do yourself today. Pull the coil wire out of the opti-spark. Look inside the terminal end on the coil side. Write back and tell me how crusty it is. Go ahead and clean that out. Clean the tip of the coil plug. Snap it back on and see if it does not clear right up. If that does the trick, the opti-spark may be fine. Where the coil wire snaps into the coil is the other weak link of the LT-1 design. Water/moisture gets up inside the coil wire boot and causes the engine to run terrible. The autoparts stores sell an gel that you can dab between the coil and wire to keep the moisture out.

If cleaning the coil and coil wire does not do it, don't be surprised if the Vette Dr. suggest replacing the whole unit opti-spark unit.
Thanks Chris, I'll try that tomorrow after work. It is almost 9pm here when i got your last post. But, I will try that before I take it to the Vette Dr. Sounds like good advice......again. Also, when i went to remove the coolant recovery tank to wash the inside, I noticed that the lower radiator hose and one of the heater hoses were collapsed flat. I went ahead and cleaned the tank, and refilled with 50/50 mix. I restarted and drove the car, and the hoses are now round again.....whats up with that. Should i go ahead and replace the hoses, or is something else wrong. It is running about 200F, and doesnt seem to be overheating. Let me know what you think of that weird problem.

opti spark

also I know allot of people that have retro fitted that system.
They put a hose in it and give it some air from the engine, I believe something like positive pressure. check out a new model I think that GM did a fix and allot of people are just adapting over.
There is a great web site on just the opti spark, some guy had taken one appart and took pics and I think he has a parts list too
I'll get back to you on that.
used to have a 92 triple black. among others.
Don't know about the hose question. Depending on the mileage, it is never a bad idea to replace with good quality hoses.

Just don't let any coolant spill on the opti-spark, or we will have to start this thread all over again.
re start thread

Hey sorry,
i won't post it here okay.
would want t see this thread again.

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