NO power/ acceleration with blinking CEL

Ok for the past several days I've been having no power/accel issues
with my 01 Elantra . I've had the codes read at AutoZones AND the
dealer but no error codes are found . I've replaced the TPS 3 times ,
replaced the fuel filter , replaced plugs and wires ,checked the
timing and timing belt . So anyone out have a clue or SWAG to what
may be going on ?

 

So are you saying the dealership cannot find the problem? Did they only
check for codes or give your motor a good going over?

I had this same issue with a 97 Ford that I owned many years ago and the
dealership tried unsuccessfully to find the problem on two separate
occassions. They finally hooked up a data logger to my OBDII port so they
could "see" it happen as I was driving over a 1-2 week period. Not sure if
Hyundai has such a device but I would think they may. Basically, when ever
it happend while I was driving I would press a red button and it would log
30 sec back in time and 5 minutes moving forward so you could see exactly
what was going on.

Ended up being a bad O2 sensor that had gotten "water logged". Once
replaced, everything was back to normal and I was a very happy camper.
Not sure if this applies here but it sounds like your looking to turn over
every rock you can for a possible solution.

 

Can't drive the car , I would risk ausing severe damage to the
catalytic converter and engine if I did so that option is out .
Apparently finding no codes is not an abnormal thing .

 

If your check engine lamp is flashing, there should be at least one trouble
code. The flashing lamp indicates a misfire. Even if there were no code,
the dealer (or any other competent shop) should be able to locate the
cause of a misfire. Misfires could be repaired prior to computerized fuel
systems. Certainly, they can be found and repaired using the same
procedures today.

 

It may one of the coil packs. Check the connections to make sure they're
clean.

 

Thats the FIRST thing I did when i had this problem , went over every
connection I could see , Had the codes read TWICE , once at Autozone
then at the dealer . The first time I had a similiar problem it was a
burnt through spark plug wire . Right now I'm trying to figure out if
the timing belt could be out in a way I can't see , but I've pulled
the covers and everything lines up . And also it only misses under
load , with the car in out of gear the engine revs up fine so Brian
may be closer to the truth of the matter . I guess I'm going to hit up
the Hmaservice website and see if I can find the resistive values on
the coil and check them out ...(Runs out the door to pull the coil
pack)

 

Do a simple vacuum test If the vacuum at idle stays steady around 18 " it's
OK if it drops way down it indicates a clogged converter or muffler
Unbolt the ex pipe & run it briefly if the power is back you know it is
the problem