Awful smell

[Mikelb]

Hey, after running a good 10-15 minutes (especially if running the car hard)... the car emits a horrible smell... you can't smell it when the windows are up... but when they are down, you're eyes will water... it smells something like burning ammonia... I figured if it smelled like rotten eggs it'd be the cat, but it doesn't smell like that, and when I bought the car, I was told the cat had been gutted... is that something worth checking out... (if it is clogged, I will just knock it out, b/c I am not gonna buy another right now... the car's a/b to be done for)...

[94StealthTT]

Even though the main cat is gutted the precats might still be there and they could be plugged. If your cars valve seals leak or is burning oil for some other reason it will plug the cats in a hurry. My main cat was plugged because my valve seals leak and it burns oil in the cat. This formed a carbon like ball plugging it up but it didnt smell. Check the pre cats maybe.

[Stealthee]

He is a 91 NA he doesnt have precats. The horrible smell is most liekly because of the gutted cat. My car puts off a pretty bad smell too.

[Mikelb]

Originally Posted by Stealthee

He is a 91 NA he doesnt have precats. The horrible smell is most liekly because of the gutted cat. My car puts off a pretty bad smell too.

Well, the car's never made this smell before... I have had it for 1 yr now... and never smelled it before... I have noticed that at idle, the car runs rich... At high RPMs it seems to lean out... I'm not really sure, but could that be the cause, and what would cause the car to do so...

[Stealthee]

Originally Posted by Mikelb

Well, the car's never made this smell before... I have had it for 1 yr now... and never smelled it before... I have noticed that at idle, the car runs rich... At high RPMs it seems to lean out... I'm not really sure, but could that be the cause, and what would cause the car to do so...

It most likely doesnt lean out up top. I know another guy with a modded SOHC. He has a AF guage and it stays pegged rich all the way up high in the rpms. Running rich could be the cause of the smell.

[Igovert500]

Have somebody follow you, and get on it pretty hard. Find out if they see any smoke at any time, and if so, what color. Also, you said you couldn't smell it inside, so I'm guessing it isn't your ECU, but when the caps leak in teh first gen ECUs, they let off a pretty nasty smell. It's covered in teh AVPRO website in teh FAQ. Other than that, you are really going to have to trace this smell, check under the hood and make sure you aren't burning anything via heat or anything bad like that. You definantly don't want a fire under the hood.

[Mikelb]

I've had someone follow me... no smoke, but the smell is awful... they definitely smell gas... though there's something else there too. They couldn't tell me what it was though...

I am certain that it was running rich at idle... and it used to run really rich all the time, but I fixed the wires on the TPS... and after that, it ran better...

[Igovert500]

You know what. You probably have an exhaust leak. If it is in the engine bay, or around the downpipe area, it would be ALOT closer to you, than when the exhaust exited completely out of the tailpipe..making it more noticeable to you now. Perhaps a bolt/gasket came loose, perhaps the flex section in your downpipe is leaking, etc. Check it out. Just a thought.

[Mikelb]

Originally Posted by Igovert500

You know what. You probably have an exhaust leak. If it is in the engine bay, or around the downpipe area, it would be ALOT closer to you, than when the exhaust exited completely out of the tailpipe..making it more noticeable to you now. Perhaps a bolt/gasket came loose, perhaps the flex section in your downpipe is leaking, etc. Check it out. Just a thought.

I'll definitely check this out...

Also, if I open the outside vents on my heater, I can smell it...

The smell isn't there when the car first turns on... it's only after it gets hot... I ran the car really easy, and it got a little better... then I ran it really hard... and it got unbearable... I'm pretty sure that it has something to do with the exhaust...

I've also noticed, that infact, I was wrong... it runs rich all the way up the RPMs... seems to get worse at higher RPMs, but no smoke...
I did have smoke one night... and it was very rich... I thought a/b lighting a lighter behind the car (but b/c I supposedly have a hollowed out cat, I feared an actual fire)... that only happened one night... I haven't actually gotten beneath the car to check if the exhaust turns red... but when my last cat went bad, there was smoke, and sparking... so I'm not really sure...maybe I should unbolt the exhaust at the cat and see what it does...

[talskinyguy]

Originally Posted by Stealthee

It most likely doesnt lean out up top. I know another guy with a modded SOHC. He has a AF guage and it stays pegged rich all the way up high in the rpms. Running rich could be the cause of the smell.

Any AF gauge that isnt a wideband will do that. Stock o2 sensors are more like 14.7:1 AF sensors, They show .5 volts at 14.7:1, close to 0V at anything leaner than that and close to 1V at anything richer. So they are basicly useless.

[Stealthee]

Originally Posted by talskinyguy

Any AF gauge that isnt a wideband will do that. Stock o2 sensors are more like 14.7:1 AF sensors, They show .5 volts at 14.7:1, close to 0V at anything leaner than that and close to 1V at anything richer. So they are basicly useless.

Aha. I guess that would make sense. Thanks for tyhe correction.

[Mikelb]

FYI, the cats are in fact, NOT gutted... the guy who sold it must've been trying to make a point of performance and get it off his hands...

I'm not certain which gasket might be blown... it's gotta be on the backside of the engine, it feels as though the spark plugs are breathing...