Cats are glowing red and smoking?

[jibbby]

My friend has a 1994 SC400 and the other morning he started his SC4 and he noticed smoke coming from under the car..He looked under the car and the cats were glowing bright red....He turned off the motor, then let it cool..Turned it back on to the same effect and with very little engine power when driving....

I told him his car is running too rich and probably his ignition coils are bad...Does that sound about right to you guys? He is going to Napa for the coils today and I really hope I did not mis-diagnos the problem....

 

[Anaema]

if thats the case, then the car could probly use some injector cleaner and a new air filter. or maybe just a whole tune-up.

 

[jibbby]

Anaema - I don't think a tune up is in order here..This is failure that happened immediately...I also owned an SC years ago that had the cats glowing red and ran with 25% power when I first purchased it...I changed the ignition coils along with the caps and rotors and that all corrected the problem....

 

[Anaema]

yes, that would be right. the coils going is the only thing that i can think of that will make the whole engine run hot all at once. what with most of the plugs not firing with enough power, or even firing at all.

 

[gte]

His converter(s) may have collapsed as well

 

[LondonBenji]

Guys, I doubt there is anything wrong with his injectors.....

He isn't firing on all cylinders, obviously spark isn't happening in some way or another, why that is it could be anything, on my Fiat Punto I think it was the coils.

They are glowing red because you are pumping a neat mixture of fuel and air ready to combust down your exhaust and when it gets hot enough it ignites it there, hence why it is getting so hot, effectively turning your exhaust system into an afterburner!

The cats are probably dead now, the oxygen sensor in the exhaust system may be dead.

 

[miwise]

I concurr with the spark theory. Obviously need to check the coils (I believe that they should have about 11500 ohms resistance b/w the plug out and the igniter input). He didn't have his engine cleaned lately did he? If so, the plug holes tend to collect water and any detergent that would have been used along with the water could have caused the plug wires to foul. I'd replace the plug wires, plugs, caps, etc if they aren't very old. Bad o2 sensor maybe causing a too rich scenario, but that should throw a code I'd think. Also, if its misfiring (should be if anything is fouled), that should throw a code as well. . .mine did. Anyways, I hope you and your friend figure it out. Cats are most likely toast, literally. The catalyst brick is probably melted. Good luck!

 

[Anaema]

Guys, I doubt there is anything wrong with his injectors.....

He isn't firing on all cylinders, obviously spark isn't happening in some way or another, why that is it could be anything, on my Fiat Punto I think it was the coils.

They are glowing red because you are pumping a neat mixture of fuel and air ready to combust down your exhaust and when it gets hot enough it ignites it there, hence why it is getting so hot, effectively turning your exhaust system into an afterburner!

The cats are probably dead now, the oxygen sensor in the exhaust system may be dead.

thats the theory. apparently its a pretty serious problem in fuel injected rotary engines.

 

[Zuffen]

Here's atheory.

The EGT's (exhaust gas temps) are high as the engine is running in limp mode.

When in limp mode the engine retards the timing to stop detonation.

The retarded timing makes the car such a slug even a dummy would notice.

I'd be looking for a faulty sensor, start by checking the error codes and work from there.

First thing I would check would be to see all loom plugs are still where they belong.

I don't see this as a lack of fuel more a late firing of the coils.

I wouldn't expect coils to be the problem (sorry Jibby) nor any ignition unless an entire ignition system (one dizzy) is down but that would be obvious, even to me.

O2 sensors would be high on my list.

 

[jibbby]

Ok, it my understanding prior to this thread that raw fuel is being sent thru the motor and into the exhaust causing the after burn affect in the Cats like LondonBen suggests..... Non firing cylinders is most likely the culprit as I stated this to my friend....

From my past experience the ignition coil was the problem, but as you guys suggest, I did tell my friend to first check the plugs, wires, caps, and rotors and maybe even look for a severly clogged fuel injector or two...I told him the reason the car is running with no power is because one or more cylinders are not firing..

I was not aware of the possibility of the O2 sensors and cats being cooked and fried....But that makes perfect sense....

Let me ask you guys this - What would happen to the cars operation if the 02 sensors are cooked as well as the cats from this?...Would the sensor reads being sent to the ECU foul the engine into running sloppy? What would happen to the cats?..Would they clog and restrict exhaust flow once cooled or become straight thu flowing cats? Not sure of the aftermath to this problem...

Thanks again for the replies (Anaema, LondonBen, Miwise, Zuffen, and 2uzgte) you guys are on it......

 

[gte]

If the 02 sensors are bad, the car could run poorly, but usually the ecu is intelligent enough to recognize this, disregard the signal and then throw a check engine light.

Too much fuel can damage a catalytic, that cat would not blow itself through every, but it could collapse on itself further impeading flow

Ok, it my understanding prior to this thread that raw fuel is being sent thru the motor and into the exhaust causing the after burn affect in the Cats like LondonBen suggests..... One misfiring cylinder is most likely the culprit as I stated this to my friend....

From my past experiences the ignition coil was always the problem, but as you guys suggest, I did tell my friend to first check the plugs, wires, caps, and rotors and maybe even look for a severly clogged fuel injector...I told him the reason the car is running with no power is because one cylinder is not firing..

I was not aware of the possibility of the O2 sensors and cats being cooked and fried....But that makes perfect sense....

Let me ask you guys this - What would happen to the cars operation if the 02 sensors are cooked as well as the cats from this?...Would the sensor reads being sent to the ECU foul the engine into running sloppy? What would happen to the cats?..Would they clog and restrict exhaust flow once cooled or become straight thu flowing cats? Not sure of the aftermath to this problem...

Thanks again for the replies (Anaema, LondonBen, Miwise, Zuffen, and 2uzgte) you guys are on it......

 

[jibbby]

That makes sense....

Another question for you experts....There are two ignition coils and if one fouls that would then cut off 4 cylinders from firing...Correct? Could an engine even run on four cylinders on the V8? That is my only dilema about the coils, but my friend does say the car feels like it has no power what so ever when running which leads me to believe it is the coils. One cylinder out from a bad wire, rotor, clogged fuel injector, etc... there would still be some adequate power right?....

See what I am getting at here...He is working on his car tomarrow....

 

[Zuffen]

Because each distributor runs half of each side of the engine any fault on one ignition circuit (be it wiring, coil, rotor, cap etc) would allow unburnt fuel into the exahust system on both sides of the engine.

From there is will be forced down the exhaust system.

I've seen flames out of the rear of rotay's where they are running so rich the unburnt fuel travels the entire length of the exhaust.

 

[jibbby]

Forgot about this thread....The problem has been corrected and it was a faulty ignition coil that was bad after all...He replaced it and the car is back to normal no damage to the cats or 02 sensors as far as my friend could tell...

I never knew the motor could run with 4 pistons not firing...WOW...

 

[rivmasta]

And here was me thinking if your cats are glowing and smoking then your tabbys are radioactive with a cigarette addiction...



surely running on 4cyl would be seriously noticable under the right foot?!!?!