PING- HT/Others 2003 Sonata- occasional stalling/lack of power/hesitation

If it was a GM, I would say crank sensor. GM's are notorious for this exact problem due to heat. I had to do my GM twice because Houston heat ate the crank sensors. However on your vehicle, idk. I could not find much on the Kia website either for G 2.7 DOHC > Crankshaft Position Sensor (CKPS).

There is a lot on the web about it though. 43,000 hits like this one for "hyundai 2.7 crank sensor"

"#3 of 10 Re: Why? 2003 Hyundai Santa Fe 2.7 has has occassional JERK during normal drivg [luckyflorida] by pelican19 Jul 16, 2008 (7:34 pm) Replying to: luckyflorida (Jul 05, 2008 11:15 am) We had the exact same problem with our 2003. Did it twice in one day at

65 on the NJ Turnpike. Took it to the dealer and they could not find the problem. Way too scary for us. Someone put it in my head it could be the transfer case since the 2003 is All time 4WD. Turned it in for the 2007 Limited AWD. Since then the second owner started to complain to the dealer about this. ( Have a close friend in the shop) and after a few visits they replaced the crank position sensor. Been jerk free for 3k miles now. Have them look at that."

My Taurus SHO had same symptoms from chronic CPS issues due to water pump seepage that was hard to diagnose as all was dry by the time we could get to the shop. Drove us crazy until changed out (along with new water pump) and no problem after that.

I'll add to what everyone else has said, replace the crank sensor. I had the same problem you described, runs well when cold, as soon as it gets pretty hot cuts off. There's a magnet in the sensor that loses its power when hot. On a I-4 its a pretty expensive to replace, (its behind the timing belt) but I understand on a v6, its not to much of a problem.

Thanks all for the input. I can see that a failing CPS can be the culprit. It's due for the T/B and water pump here in about 9k. The missus stays in town for now and I'll probably do the belt, w/p and CPS myself. Dumped enough cash into this car already.

OT- I'll do it myself and save some money. Read the cover of US Today....holding onto all the money I have and will buy parts off EBay...

Steve

Greetings all;

As you know, I have been struggling with this issue for awhile. V6-2.7L,

110K miles.

Here's the "done" list:

New coil pack, new plugs, new wires, new MAF, new battery (it suffered AZ heat!), new downstream O2 sensors. It will run great for a few weeks, then on occasion it'll fall on it's butt, no power and some times just die. Give it a few minutes, it'll start and run great for weeks. Fuel pressure is dead on. Last code I got was cyl 3 misfire. I am at a complete loss. I scoured hmaservice.com and cannot find any schematics. I read up on the basics of the ignition system:

Engine operating conditions (speed, load, warm-up condition, etc.) are detected by the various sensors. Based upon these sensor signals and the data stored in the ECM, signals to interrupt the primary current are sent to the power transistor. The ignition coil is activated and timing is controlled at the optimum point.

Power Resistor? What else is inline from the ECU to the coil?

Other possibles- fuel filter? fuel pressure regulator? fuel pump? I believe it to be ignition related...

TIA,

Steve in AZ

No trees were killed in the sending of this message. However a large number of electrons were terribly inconvenienced.

No trees were killed in the sending of this message. However a large number of electrons were terribly inconvenienced.

..

If you're continuing to get a cylinder #3 misfire only, look away from the crank sensor. There's something going on with cylinder #3. If the problem jumps around randomly to the different cylinders, then you should suspect the crank sensor. The question is what about cylinder #3 is causing the issue.

Can we presume the plugs, wires, and coil are all okay after replacement? If not, some swapping is in order. Swap the #3 plug with #2 or #4 in the front bank. This will make it easy to replace if it's defective. And if you're taking the plenum off, take another moment to swap the #3 injector with the #4 or #2 injector in the front bank. Do not swap with cylinder #6, as this cylinder is fired at the same time as cylinder #3. Even if you don't think swapping the plugs isn't necessary, it may be a good check, as swapping the injector may give you some information. If the misfire moves to one of the cylinders in question, you've identified a faulty component.

You might also switch where the #3 and #6 wires attach on the coil. This will have the effect of firing the plugs in the reverse direction (goes from the coil through the wire to the block through the companion plug and back to the coil through the other wire). If the misfire moves to cylinder #6, you've identified the issue is with the coil.

Thanks HT....will review it all. SSSHHHHH! It's been running great!!!

Steve

If you're continuing to get a cylinder #3 misfire only, look away from the crank sensor. There's something going on with cylinder #3. If the problem jumps around randomly to the different cylinders, then you should suspect the crank sensor. The question is what about cylinder #3 is causing the issue.

Can we presume the plugs, wires, and coil are all okay after replacement? If not, some swapping is in order. Swap the #3 plug with #2 or #4 in the front bank. This will make it easy to replace if it's defective. And if you're taking the plenum off, take another moment to swap the #3 injector with the #4 or #2 injector in the front bank. Do not swap with cylinder #6, as this cylinder is fired at the same time as cylinder #3. Even if you don't think swapping the plugs isn't necessary, it may be a good check, as swapping the injector may give you some information. If the misfire moves to one of the cylinders in question, you've identified a faulty component.

You might also switch where the #3 and #6 wires attach on the coil. This will have the effect of firing the plugs in the reverse direction (goes from the coil through the wire to the block through the companion plug and back to the coil through the other wire). If the misfire moves to cylinder #6, you've identified the issue is with the coil.

No trees were killed in the sending of this message. However a large number of electrons were terribly inconvenienced.

I know that both plugs attached to the same coil is fired at the same time, resulting in the "waste spark" to the cylinder that's not ready for ignition, but I don't understand what hyundaitech said.