QuestionQUESTION: i have found #1 and 3 cylinders are not combusting the
fuel, if i
> pull the plug wires off there is no change in the motor.
> and if i pull the injector power feeds off, there is no change ,
except
> there i no unburned fuel going through the catalytic conv. so there
is no more
> overheating on the exhaust.
>
>
> so now i a m totally confused i can drive it w/ 2 running
cylinders,
> ready to go to the dealer .................aaarghh
> note
have confirmed timing TDC and all marks on the timing belt
it seems strange that 1 and 3 are the problems
I will pull those injectors soon and clean them..
Any wisdom for me????
just so you know, i have replaced :
timing belt
plugs
fuel filter
drained gas tank out
cleaned fuel pump
verified spark all cyl.
ANSWER: Hi, Todd. I think you may be looking at an ignition misfire here, even though you've verified spark. Injector misfires are rarely so bad that there is not a power change when the cylinder is depowered. If you would, I'd like you to answer a few questions so I have a better idea of what's happening and exactly what's been determined.
1. Do you have the 4 cylinder or V6 engine?
2. How did you test for spark?
3. Why did you replace the timing belt, scheduled maintenance or a failure?
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QUESTION: 2.4 4 cylinder
yes it was there spark that is
missing teeth on orig belt
50k miles belt wasnt totally cooked, and engine sounds fine, good compression all cylinders
ANSWER: Alright. A few more questions now (sorry).
4. I cannot recall which cylinders have coils on top of them. Is it 1 and 3 or 2 and 4?
5. I'm not really questioning that you verified spark. What I'm interested in is exactly how you determined you had spark. For example, if you verified you had spark out of the coil, we know the coil is okay, but don't know about the plug and wire. This information will help me decide whether you really need to check more things in the ignition system or whether you should move on to other areas.
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QUESTION: Hello and thanks again for the replies
Idea: if you take off the crankshaft fan belt pulley,
and looking at the crankshaft,the cog pulley for the timing belt has a small "O" stamped on it. Is this a TDC reference mark? Because if it is, it DOESN'T align with the sensor plate. The only mark shown in the factory manual is the crankshaft position sensor plate, and a notch in the block.
I have checked the timing belt marks over and over.
I was able to confirm spark by pulling off the leads, and a spark was evident, also pulled the plus on 1 and 3 and connected the to the plug wires,grounding them ..spark...
Now on the other hand I cant figure out how to do that w/ the coil over cylinders(2 and 4), but those ARE the only working cylinders! So back to that quuestion on the "O"
If i new that answere i'd be more assured the timing belt is not an issue.
ANSWER: I'm not sure about the "O." I've never particularly paid attention to it. But the good news is that this isn't a cam timing issue. That would affect all cylinders equally. So if two were dead, the other two would also be dead, meaning the engine wouldn't run at all.
The common mode of failure of the plug wires is that the plastic tube that goes into the spark plug hole breaks down, and the spark arcs out through the plastic onto the plug hole. First, check to make sure this isn't happening. Pull the wires off the plugs and just set them back onto the plugs without snapping into place. Then start the engine. Now, gradually pull one wire up off the plug. The spark should continue to jump *out of the end* of the wire onto the plug (or to the side of the plug hole once you get it far enough away from the plug). If the spark is coming out of the side of the wire, the wire needs to be replaced. Repeat this test with the other wire. I'm assuming you'll have spark coming out of the wire somewhere based on the earlier results you've given me.
If the wires check okay, then move the #1 and #3 plugs to cylinders #2 and #4 and put the plugs that were in 2 and 4 now in 1 and 3. While you have the plugs out, make sure you don't have any carbon tracks running down the porcelain. Look inside the wire boots for tracks of carbon as well. (Furthermore, if your old plugs had such tracks, you should expect they'll be present on the wires). Any plug or wire with a carbon track should be replaced. Presuming you've found none, restart the car when you have the plugs switched. If the misfire moves to cylinders 2 and 4, the plugs are the issue. If it stays with 1 and 3, the plugs are not the issue and we can move on to other things.
You can perform a similar test with the injectors. Swap 1 and 3 with 2 and 4 to see if the misfire moves. This will tell you whether the injectors are the issue.
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QUESTION: thanks for the quick reply
I tried swapping plugs
bought new wires fro 1 and 3 cylinders, 2 and 4 are coil over
still have no combustion on 1 and 3 there is a spark, but it must occur at the wrong time
DAMN!!!!
ANSWER: It's pretty safe to say that the ignition system isn't the problem, then. Move on to the injectors. Swap 1 and 3 with 2 and 4. Similar to moving the plugs, if the misfire moves, you know the problem was the injectors. If it stays on 1 and 3, you know it wasn't the injectors.
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QUESTION: Is it possible that the cams are out of time w/ the crank?
because i have fuel and spark at 1 and 3 cylinders, and no combustion
I understand that for each complete revolution of the crank , the cams go around only half a cycle?
If i turn the crank once the cams dont end up on thier mark, 2 turns bring them back to the timing marks on TDC.
If i was that far away i would think i would have valves hitting the piston...
Can i be so brave as to advance the crank one turn with the tiimg belt off, leaving the cams on the TDC mark??
Seems impossible.
note : as i indicated earlier, when i position the crank on TDC, with the plug out i can see the #1 piston at its apex, and assume the valves are closed. Or should be...
Maybey i gotta take the valve cover off to see that.
before i go and remove the timing belt for the 20th time..
thanks 4 yur help may-tee.
ANSWER: This is not a camshaft to crank timing issue. As I said in my last reply, if it were, the problem would affect all cylinders equally. All that's necessary to check the cam timing is to turn the crank pulley so that the cam marks are properly aligned and verify the mark on the crank pulley is aligned with the TDC mark on the cover.
Your next step should be checking the injectors by swapping as mentioned above, or performing a compression test.
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QUESTION: hi HT
swapped the injectors today, cleaned the susupected units, but still the same...
will do compression test tommorrow, have already done this, but will double check
judging by the way it sounds w/o the plugs in those holes...i believe i have full compression on 1 and 3..
I really hate to bring this puppy into Hyundai dealer..
got over 60 hours on my wifes baby...dont want to give in.
Thanks for all your help..much appreciation..
i will be in touch tommorrow HT
ANSWER: Out of curiosity, does the misfire tend to go away when you rev the engine? If so, you may have intake manifold leaks on cylinders 1 and 3.
Also, it's possible that #1 and #3 injectors aren't being fired properly by the ECM. To check this, you'll need a noid light (a light with resistance similar to that of an injector designed to be plugged into the injector connector).
Nonetheless, the compression test is a good thing to do.
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QUESTION: compression test was ok
so back to the timing issue i guess
how do i know if the injectors are firing at the right time, or even the spark for that matter?
wife wants to bring it to the shop...
not much left for me to do....?????
AnswerWe've verified spark, but we haven't verified that the injectors are firing. To test this, you'll need to purchase a noid light (presuming you don't have one already). A noid light is designed to plug into the injector connector in place of the injector. It has a resistance similar to the injector's so it won't damage your engine computer.
Again, this isn't a timing issue. Not only won't it affect only two cylinders, but you've just proven that you have compression.
The injectors and spark plugs fire based on data received by the engine control module (ECM) from the cam and crank sensors. Since cylinders 2 and 4 are firing normally, we know that the ECM is receiving this signal properly.
