my car is having trouble burning gas.....? it chokes like a human coughing, when accelerating from stop. Exaust sounds heavily loud The car shakes. Car can not accelerate at all from 0-40mph. but after 40 mph or so, it runs a little bit back to normal. The engine light recently light up but then dissappears.... What is wrong w/ it? need help asap please, its painful for me to see my car like this.... knowing that if anything major happens i would not have the money to fix it...... i have a 92 SC400. Has one of the cylinder died out? Bad gas quality? Spark Plugs? O2??? IT SHAKES AND EXAUST SOUNDS LIKE ITS CHOCKING. emission? any proffessional help would be greatly thankful. thank you.

 

If there's professional opinion, I'm the furthest thing from it... but I'm wondering if you recently washed your engine bay down with a hose or something... it sounds like you're having ignition trouble.

Those are some deep spark plug wells on the SC4

 

Also sounds like an ignition problem. Do you happen to know when's the last time maintenence was done? Also doesnt hurt to do a compression test. From my experience with any check engine light going in and out on my SC it was from my alternator.

 

make sure you check the kanooder valve also, they tend to get built up with carbon and stick

 

Swollio, I don't know if I have welcomed you to CL. If not, WELCOME!!!

Also, allow me to introduce you to the search function. The top left of every page contains a dialogue box which enables the entire database that is CL to be searched. Here's what I was able to find that may lend some insight to your problem.

https://www.clublexus.com/forums/sho...ight=coil+pack

https://www.clublexus.com/forums/sho...ignition+rotor

https://www.clublexus.com/forums/sho...=washed+engine


Enjoy

 

Your plugs (1 or more) are fouled. Replace them all and gap properly according to your emissions label located under the hood. I had the same problem

 

checked the plugs already, they are all good. had some suggestions from people, and so far i think its the catalytic converter...... anyone had a catalytic problem before? explain.... thank you

 

let's examine the problem.

Under heavy load the car cannot produce power. (from a stop)

You need to force the right amount of everything into it to make it work. Air going in isn't a problem, so look at air going out. I suggested the convertor to you in PM.

Now the other side of the coin, fuel. There seems to be a chance the car is starving for fuel pressure since under the demanding acceleration from a stop it chokes. You need to check your fuel pressure and have your cat convertor inspected in that order.

I'd do those two tests first and immediately. If i were a betting man, I'd say you do not have enough fuel pressure. These cars have a fuel computer AND fuel pump. The computer has been blamed for a few different problems more than once, so have the fuel pressure tested first, then have the cats checked.

 

By the way did you tick anyone off lately? Your car could be running on dixie crystals

 

I would venture a guess one of your coils has packed it in.
Check to see you are getting spark out of both your coils.
If one of your coils packs it in no engine light will come on but you will be running on 4 cylinder only.
As your revs increase the problem will seem to be less only because your revs are up and the 4 cylinders that are firing will carry the 4 that are not.
Hope this helps.

Rob

 

I think Pirate400 had this same problem a few months ago. He thought it was the Converters but it ended up being something in the ignition system like a plug wire.

 

I had a convertor problem ona previous car but not the Lexus. The material inside the cat broke up and came out of the cat, clogging the muffler. This does not result in "coughing" of the engine. My symptom was a severe limit on top speed and drastically reduced power. The car would not get over 50mph and took a while to get there. If you are still experiencing the noises you described I would research the path OLT discussed with your fuel computer/pump.