Funny Smell

SON240sx Automotive
1

After beating on a the car a bit to check if it was working fine (I just bought it), after stopping at a light, I started to smell a rotten eggs smell. It smelled like sulfur, if that helps. I’m pretty sure that it is the catalytic convertor overheating. A new catalytic convertor and O2 sensor was put in right before I bought the car (emission test).

Another problem is that around 1500-2000rpm, especially cruising at that rpm, the car jerks, kinda like the engine suddenly makes no power, and then all of a sudden its back again, but it happens very quickly. Going uphill at a low speed in first (its an automatic 1993 with a KA24DE with 206k btw) will enhance the stuttering since its a low speed and it’s easier to feel. It will do this at higher speeds too once the gears change to bring the rpm down to that level. It is more apparent when the throttle is mildly depressed. After crossing 2000rpm, its all good, nothing wrong there. Idle is pretty smooth too compared to other 240’s, and no stalling issues.

I believe this car might be running rich to cause the cat to overheat. The performance is not as strong as 155hp should feel in a 2800 lbs. car, but that just might be me or engine age.

I suspect the running rich problem because it kinda smells like fuel when you rev it with the door open. The gas mileage is pretty shitty (first tank, almost empty now, distance travelled: 320km so far). My dad’s 3.8L V6 Oldsmobile gets like 500+km to a 70L tank…can you guys post your km/L mileage or the total distance per tank along with the type of driving? It would really help put my problem into context.

I bought throttle body cleaner, and I plan on spraying it into the TB while the engine is running, as it instructs you to, but I’m afraid all that crap will go into the engine and cause further damage. Taking the TB off, I believe it would require a new gasket to put back on, right? Plus I’m not mechanically inclined at all, I’d need a thorough DIY article with several pics to even consider doing it myself.

Also, I’ll prob take off the MAF sensor, and clean it with TB cleaner.

Thanks for reading this long ass post, I wanted to give as much info as possible to assist your diagnosis. I hope I can get some ideas and suggestions.

2

Clutch.

3

Nope.

All of mine have been about 600km to a tank, so there is definitely something wrong there.

I’d start with the basics rather than taking random stabs at cleaning parts. I’d start checking ignition timing.

4

its probly ur timing belt

5

I won’t lie, I didn’t bother to read the whole post. I skimmed through, saw shitty mileage, acceleration issues and, rotten egg smell.

6

Ok, now I don’t feel bad about my post…

You’re an idiot. KA uses a timing chain. It also wouldn’t create all the symptoms he is experiencing.

7

nah, my money is on muffler bearings.

seriously though, the sulfur smell could also be your battery being overcharged and cooking, is it having any problems starting? could be happening while you’re beating on it because higher RPMs will charge the battery better. it’s more likely that it’s the cat, though.

8

my bad didnt no tat cz my friend had a problem tat was similar nd it was his timing belt

9

Speak less, read more. Become literate, then try and communicate.

10

man, either do what DJPyro said, or end yourself. I’m fine with either one, just as long as i don’t have to read another incoherent post from you.

11

yo …if u have nothing polite to say then dont say anything

12

egg sulfur smell is water in the gas no?

13

i also get poor gas mileage. cud be due to winter and idling for a few minutes b4 i start driving. last time i travelled abt 300km b4 filling up 38litres, which i attributed to thawing weather but was getting worse previously when it was colder. also jerkiness is a problem at low speeds gear1-2 with autos.

14

For those who don’t want to read the whole post:

-1500-1700rpm stuttering, as if its missing
(similar feeling to when my dad’s 3.8L V6 car had 1 bad coil, and would hesitate at certain rpms, cuz it was running on 5 cylinders)

-rotten egg smell comes when car is driven hard, e.g. more than half throttle

-revving car gives fuel like smell…not in cabin though

-overconsumption of fuel, no burning of oil or coolant whatsoever, no leaks either

-idle is smooth and quiet once rpm goes down after warmup, initially a little loud…but its a KA lol

-emissions passed recently after EGR cleaning, O2 sensor and cat replacement

-this is not only in 1st to 2nd, it happens in 3rd as well, its rpm based, not gear based (happens around 1500-1750rpm, usually closer to 1700rpm)

-battery is fine, I sat in the car for 4 hours and listened to music using the battery only, and it started like a champ the next day

Anyways, HOLY SHIT 600km/s to a tank!? OK…something is definitely wrong with mine then. BTW its sad to see someone suggesting its my clutch, but funnier when someone right after suggested I change my timing belt on a KA24 lol I had a little laugh…no offense, I completely understand where you’re coming from with the “skim reading a long post” routine DJPyro, and thank you for your suggestions.

Im getting the feeling I should make shorter posts (BAD for diagnosis)…after all it was I who attacked SON with a wall of text earlier and caused critical damage lol.

And lets not go off topic now, we’re here to help each other…this IS the Technial Section.

15

check yoour headlight fluid

16

someone pissed in your gas tank before you bought it

17

did you fart???

lol honestly tho have you done any of the baiscs?
read codes
a small tune up?
oil change?
clean mafs
check exhuast for leaks?

18

Rotten egg smell is busted cat.

19

1500-1700rpm stuttering, as if its missing
(similar feeling to when my dad’s 3.8L V6 car had 1 bad coil, and would hesitate at certain rpms, cuz it was running on 5 cylinders)

sounds like you already know the answer to your problem… rotten egg smell is from a failing cat or one that is being soaked in fuel and unable to operate properly.

Either that or the timing belt LOL.

20

I got TB cleaner and Brake Cleaner today, hopefully I can clean both the throttle body and the MAF on the weekend. It got to 346km before the tank was almost empty and I refilled, also putting winter injector cleaner.

As for basic checks like codes, there is no engine light, and there was none before I bought the car either. Maybe it was cleared long time ago…does anyone have a scanner to read the codes?

Another thing, how do you exactly check for vacuum leaks with no tools or sensors? Is it easy to do yourself? I’ll do some more research at school tomorrow.

Honestly, the best solution would be to meet up with someone who’s good with KA’s and they could help me out. I’ll pay in pizza and drinks, plus cash if necessary, depending on what kind of labour is required.

I’d rather fix it and learn new stuff from a helpful fellow 240 owner rather than dropping it off to a random shop and wait until they throw parts at it until the problem is gone, then charge ridiculous labour fees.