Hi my 2000 Elantra is running rough, sputters, stalls, and sounds like it's missing at high speed.

It's not showing any codes

It's got a new clutch, water pump, timing gear, fuel filter, air filter, it's not over heating, and it has new plugs wires etc. etc.

My son checked the new plugs, and said that one of them was badly fouled which leads him to think faulty fuel injector. Are there any other things that might be causing this problem?

If I took my car to a Hyundai dealership, would their computer be able to tell us which part it is that is malfunctioning?

Thanks for all your help, it is GREATLY appreciated.

 

When you said it's not showing any codes do you mean the CEL isn't on? Because even without the CEL on, there could still be codes in the computer. Get the computer read first and let us know what you find.

 

Spritz some CARB along the seam where the intake is bolted to cylinder head at idle, see if it does anything when shot of carb gets near the #2 or #3 port...

Common intake gasket to crack on that engine.. chase mis-fire all day, spritz of carb will show you where.

 

I took the car in, (and forgot to mention earlier that I did have one CEL that I was already aware of, it is a bad purge valve sensor code which I've been assured by people on this site and at the dealership has nothing to do with the way the car runs) and NO other codes showed except the Purge valve code. The person who ran my car on the computer said the same thing about a possible cracked/leaking gasket, he also said it could possibly be a Mass Air Flow Sensor Beginning to fail but the code doesn't show yet because when the cylnders fire as they should, the computer resets itself (his words not mine).

Also I forgot one possibly important bit of information in my initial post. When my son checked the new plugs, one of them was badly fouled and the others still looked brand new.

Any further thoughts?

p.s. I love this site. You guys know what you're doing!

 

Did you spritz the intake gasket to see if it was leaking ?

If you aint got a can of carb, use a spray bottle of water set for stream..

If you gots good hearing, you will hear a loud slurping/hissing sound as the water is sucked into the intake tract.

Should take no more than 2 minutes of your time.

 

I have printed out this thread for my son. Unfortunately Teal and Goose season opened this morning so it might take a little while for his focus to return to my car. But I'll be sure to post back and let you know the end result.

Thanks!

 

Be nice if they had a week or so long open season on goose around here.

Them things everywhere, overcrowding.

 

So I had both the Mass Air Flow sensor and the gasket replaced. The car runs better now while in gear, doesn't stall anymore, and I don't need to rev the engine and play with the clutch to keep it from stalling out at take off or in reverse anymore. But it still idles rough, and you can see the RPM dial move up and down when the car misses. This is only at idle though, it runs good otherwise. Did they miss something, put something in upside down, does a computer need to be reset, or could it be something else?

This is a 2000 Hyundai Elantra with 156,000 miles.

Any more clues or input? I really need to keep this thing running for awhile more.

 

Any more clues, suggestions, or ideas on why the car is idling so rough?