Cylinder Misfire
#1
10-19-2008, 06:33 PM
Cylinder Misfire
I am working on my sister's 2000 Elantra with 75K miles.I cleared3misfire codes2 weeks ago (cyls 1/3 and random).Last night the car had trouble going over 2000 rpm on the highway, and the car nowidles rough and throws a cly 2 misfirein short order.I can rev to 3000 rpm somewahat smoothly, but I can notice a misfire occurringsporadicallyduring idling as the ignition advance moves between 7.5 to 12 degrees at 800 +- 75 rpm.
After getting some info from the web and checking a haynes manual:
A. Pulled the plugs (platinum 1 yr old) and they looked good.
B.I noticed #1 ignition wire was different than the others, and may not have been seated tightly.
C. The crank position sensor pin 2 puts out 4.5 Vmost likely constant between 800-3000 rpm.
D.Thecrankposition sensor shows .98 ohms for pins 2-3 at 52F.
E. The PCV to Intake manifold tube appears to be a non-Hyndai part wich is possibly constricted or not tight.
A. All of the plugs seem to be burning correctly, but some of the heads were slightly corroded at the contact to the ignition wire.
B. Likely #1 wire was changed in the past.
C. Haynes states that the crank position sensor is supposed to alternate between 0 and 5V, but my analog and digital multimeters may not be able to pick up on the alternating voltage.
D. Haynes states that the resistance of pins 2-3 on the crank position sensor is supposed to be between 486 to 594 ohms at 68F.
I wouldn't think the car would run with a bad crank position sensor. I'm going to change the wires, and the PCV-manifold tubing, but I'm open for some assistance in debugging this problem and especially before I drop $100 for a crank position sensor.
Thanks in advance
After getting some info from the web and checking a haynes manual:
A. Pulled the plugs (platinum 1 yr old) and they looked good.
B.I noticed #1 ignition wire was different than the others, and may not have been seated tightly.
C. The crank position sensor pin 2 puts out 4.5 Vmost likely constant between 800-3000 rpm.
D.Thecrankposition sensor shows .98 ohms for pins 2-3 at 52F.
E. The PCV to Intake manifold tube appears to be a non-Hyndai part wich is possibly constricted or not tight.
A. All of the plugs seem to be burning correctly, but some of the heads were slightly corroded at the contact to the ignition wire.
B. Likely #1 wire was changed in the past.
C. Haynes states that the crank position sensor is supposed to alternate between 0 and 5V, but my analog and digital multimeters may not be able to pick up on the alternating voltage.
D. Haynes states that the resistance of pins 2-3 on the crank position sensor is supposed to be between 486 to 594 ohms at 68F.
I wouldn't think the car would run with a bad crank position sensor. I'm going to change the wires, and the PCV-manifold tubing, but I'm open for some assistance in debugging this problem and especially before I drop $100 for a crank position sensor.
Thanks in advance
#2
10-21-2008, 10:18 PM
RE: Cylinder Misfire
How old are the wires? My 97 Elantra had some go bad.
My 1.8 dohc motor has the last 6" of the wire is in the head and gets hot, cracks, and causes the wire to arc.
Look at the end for something that looks like a lighting bolt which is a sign of bad wires.
If the wires are orig I would start by changing them.
After that I would check compression and flue injectors.
Good luck and post back on what you find.
My 1.8 dohc motor has the last 6" of the wire is in the head and gets hot, cracks, and causes the wire to arc.
Look at the end for something that looks like a lighting bolt which is a sign of bad wires.
If the wires are orig I would start by changing them.
After that I would check compression and flue injectors.
Good luck and post back on what you find.
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