03 Santa Fe, hard start, weak acceleration. Later works perfectly.

I have a 2003 Santa Fe, 6cyl, 2.7 automatic w/AWD. It has about 26,000
miles and has had all the regular maintenace done and has never given me any
problems.

Today around noon, going out to run an errand at lunch time, I turned the
key and the engine cranked, but didn't start right away. Thinking I let go
of the key to quick, I tried again, no luck. On the third time, I slightly
pressed the accelerator and it started, but I didn't think it sounded quite
right, a little rougher than normal. I stared moving and there was very
little acceleration. No warning lights were lit on the dash. As I
gradually got up to speed, it started sounding rougher and didn't seem to
want to shift into 2nd. I used the shiftronic and it smoothed out some, but
still no power. I pulled over, stopped the car and restarted it. It still
needed a light touch on the gas to start it, and the weak acceleration
didn't change.

I ran the errand I needed and went back to work. I called the dealer
service department and he said the earliest he could get to it was Thursday.
A loner car would be available for warranty work if it needed to be kept
overnight, but I wouldn't be able to get the loaner until they actually
worked on the car. After talking a bit he agreed that if I dropped it off
Sunday night, he might be able to take a look at it on Monday.

About 6 pm I left work to go home. The car worked perfectly. Quick start
without pressing the gas, normal acceleration, normal shifting, etc.

At this point I'm not going to take it in (unless it acts up again over the
weekend). I don't really want to go through the trouble just to have them
tell me they can't find anything wrong.

Any suggestions would be appreciated.

- Mike

 

Crankshaft Position Sensor???

I know my 2002 had a recall on this and gave me problems until it was
replaced.

Or it could be your transmission. When you switched to shifttronic, what
gear was it in? It may have been in limp mode?

 

Based on the info, it sounds like an engine performance issue, possibly a
misfire. It may be best to take it in and let them have a quick look at
it. If it's running okay, and there are no trouble codes, and the find
nothing wrong, then take it and be on your way. If something needs to be
fixed, take the loaner and come back when it's repaired.

 

I thought about the 3rd gear "limp home" mode, but that didn't seem to be
the issue. It was in first the first time I used the shifttronic; I thought
the problem was that it wasn't shifting out of 1st, however it pretty much
acted the same way no matter what gear it was in.

I've used it several times since, and everything seems fine.

A friend of mine said he had similar effects on car he had several years
ago, and it eventually turned out to be the oxygen sensor. I was also
wondering if maybe I had something wrong in the gas. I'd been getting fuel
from the same place for a couple of months and haven't had any other
problems, though.

- Mike O.