97 Lumina runs bad after moisture

Hello,

I am new to this forum and not new to my lumina. It has been a great car for 239,000 miles and still going pretty strong.

OK, it seems after the car sits outside and after a rainy, misty, or drizzly day the car runs bad only when applying the gas pedal. It sits and idles no problem and starts without any problems. It is when I am going down the road and push the pedal more than a 1/2" it starts to miss-fire. After the car warms up the problem goes away. It seems some moisture is getting in somewhere but I can't figure it out. I had the same problem a year ago after I gunked and washed the engine.

I know it is not the fuel pump and the plugs and wires were replaced 40k ago.

Any suggestions or things I could try replacing? I was thinking a distributor but the car doesnt have one, at least when I looked at it. Thanks for the help. I tip!

Many things can cause this, when it gets dark spray some water, lightly with a spray bottle around the coils and wires, power brake the car ( safely here, block the wheels) have some do this or have someone watch for arcing around the wetted areas.

OK I will try that. Can't I just put the car in neutral and gas it up? Also, if I do see some arcing what does that tell me?

No, you need to load the engine to force the ign output to peak, this will reveal any poor electircal connections/arcing/cracked coil issues.

In electronics, we have a 50,000 volt spray that coats components with a kind of plastic/shellac. I don't know how that would hold up under vibration/heat/flexibility situations, but there is also a similar product marketed as "ignition wire" spray or something, various brands.

For all I know its the same product, but it might give your ignition (sparkplug) wires some extra life and stop shorts/arcing which may be preventing the cylinders from firing. For a $5 (hopefully) can of that, you might at least temporarily get rid of your problem.

Some mechanics I recall in the past spraying motors with WD-40, I can't remember if that was to drive out moisture or provide an insulating barrier to electricity.

In electronics, we have a 50,000 volt spray that coats components with a kind of plastic/shellac. I don't know how that would hold up under vibration/heat/flexibility situations, but there is also a similar product marketed as "ignition wire" spray or something, various brands.

For all I know its the same product, but it might give your ignition (sparkplug) wires some extra life and stop shorts/arcing which may be preventing the cylinders from firing. For a $5 (hopefully) can of that, you might at least temporarily get rid of your problem.

Some mechanics I recall in the past spraying motors with WD-40, I can't remember if that was to drive out moisture or provide an insulating barrier to electricity.

Hey thats seems like a good idea. I will look at autozone today and see what I can find. I wonder if silicone would work? I still want to test the coils at night but haven't had a chance to. The car has been running great since the weather is nice.

One more thing I noticed today. When starting the car the service engine light did not come on for a second. I thought every light should come on to test when starting a car... airbag...ect. Because it did not throw a code when it did this so maybe when I am at autozone I can see if it still threw a code.

For all I know its the same product, but it might give your ignition (sparkplug) wires some extra life and stop shorts/arcing which may be preventing the cylinders from firing. For a $5 (hopefully) can of that, you might at least temporarily get rid of your problem.

Products like these are only band-aids. If the band-aid falls off the problem is still there! Why not fix it right the first time and put that $5 towards the cost of the right parts.

Not only that but a properly maintaned vehicle runs better, is more reliable, and gets better fuel economy!

Update:

Ok I took out my ignition coils and had them test at autozone. All tested ok. I did have them get the computer codes out of my car because I have not seen the service engine soon light on in a long time, so I thought maybe the light burnt out.

Well my ses light is not working but still throwing codes. I had 10 of them. So I researched some of them. I will list them here and see if anyone has any input. Also, I did clean the egr valve out because one of the codes pertained to that.

1. Code: P0401- EGR system fault
What I did: Cleaned egr, valve was moving freely and back to closed like it should. Anything else I should check with this?

2. P0420 - Catalyst efficiency low bank 1
What I did: Read about this one. This must be the code for the missfires I had. Other than that I have no idea.

3. P0341- Cam Sensor condition
What I did: Nothing yet. I suppose I could change the sensor is that expensive and easy to do? Could someone tell me where this is or link to picture even better.

4. P0440 & P0442- Emissions leak
What I did: I know the gas cap is not causing this. I inspected the tank and lines around but could not see anything bad. I did read that luminas are know for the evaporator emissions canister vent solenoid for going bad. Is this a cheap part? Where exactly is it? Is it easy to do?

Hey I think I am learning more and more about working on cars here. Maybe soon I can learn a few more things and help some others on this site, especially with luminas. Thanks for the help so far.

Dave

Quite honestly if there are 10 codes there I would erase them and see what comes back. There is some likely hood that they where set inadvertently. Most of them wouldn't give you any driveability symptoms per say.

Typically egr codes are set when there is deris stuck in the pintle. The typical symptom is no idle and a hard brake pedal depending on how for its stuck open. The other possibility is one of the coils is flakin out which will cause it to be in a different position than expected by the PCM.

The cat inefficiency code could be the cat has worn out and is no longer functioning as intended. There is an O2 sensor behind the cat that monitors how well its cleaning up the exhaust. If it sees higher numbers than its expecting than it flags the code.

The cam sensor, Hmmm I have never personally had one of these fail. If it was unplugged at some point than it would have set the code?

The vent solenoid is either attached to the charcoal canister or on the other end of the large rubber hose that comes out of the charcoal canister. Its to late to remember. They are not terrible expensive and I'm pretty sure the dealer is the place to get them. Small and medium evap leaks can be just about anything so it may not be a bad idea to have it checked out before dumping cash into it. Although I don't they they are that much.

I had another though on those evap codes. I have had a couple that the lines had come off the purge solenoid. The purge solenoid is the thing that is attached to the coil tower bracket where it is attached to the to studs on the back side of the engine. Wouldn't hurt to make sure the rubber parts aren't cracked or soaked in oil and bloated.

Hey thanks for the input. I am going to check the purge solenoid tomorrow. The car has no driveability problems and I am not too worried about the small things, this car has 239,000 miles. My main concern with all of this was the missfiring after the car sits in a rain or moisture. My next concern is gas mileage. I also have a turn signal problem that I read will get worse and I am not up to pulling the column and airbag to change the switch... but thats another story.

I just ordered one of the scanners from amazon and will clear all the codes out when I get it. Like I said the car runs great most of the time. It is only when it sits for a few days and those misty rainy days fall then it acts up till the engine is warm again.

The emissions codes are tough to figure out sometimes. How concerned should I be with a cat not performing? I care about the environment but not enough to shell out some big bucks.. Thanks again.

I had another though on those evap codes. I have had a couple that the lines had come off the purge solenoid. The purge solenoid is the thing that is attached to the coil tower bracket where it is attached to the to studs on the back side of the engine. Wouldn't hurt to make sure the rubber parts aren't cracked or soaked in oil and bloated.

So the vent solenoid is different from the purge? I thought they were the same thing. You said the purge is on the back of the engine.. Would that be near the top, middle, or bottom? And do you possible have or seen a picture of the purge solenoid? Thanks

The vent solenoid allows the system to "vent". The purge solenoid is what "purges" or allows the vapors to be sucked from the canister and burned in the engine. Its located between the coils and the firewall right above the O2 sensor. Unless its a newer engine than its right next to the egr valve.

Clear the codes and see if they come back and then worry about them. The cat inefficiency could have been a fluke but if it comes back it should be dealt with! Air pollution is a huge problem, and emission standards are in place to help control them. Many parts of the country require emissions testing but many more are on the honor system. If we continue to stay on top of emissions repairs than likely we will be able to stay with the honor system. If not it is very likely we will all end up with very strict emissions requirements much like California, I really don't want to deal with that.

When the car is dry, there are no codes? When the car is moist with rain, you receive codes?
If it is just water moisture related and goes away, then I would assume there are not parts to change, just move to the desert with that car.:naughty:

When the car is dry, there are no codes? When the car is moist with rain, you receive codes?
If it is just water moisture related and goes away, then I would assume there are not parts to change, just move to the desert with that car.:naughty:

No, I realized that the lamp to the SES soon is out, so the light does not come on at all, I am going to change that soon.

The car runs fine in the rain. Only runs bad when it sits cold engine in the rain or mist, then I push the gas pedal. It starts fine and idles fine. The problem is that I cannot accelerate well when it is doing this. When the engine warms up no problems...