Misfire issue

[maverickdog8]

So I have read through the forum a couple times at random misfire codes. I have a 2006 cobalt 2.2L that will not stop misfiring. Throws a random multiple misfire code randomly then 30 minutes later it shuts off.

I've tried changing plugs(2x), boots, coils, ignition control module, injectors, and the ecm, but it still does it. Is there anything I am missing? I know this is a common issue, but there has to be some way to fix it.

 

[onedoughboy]

You've changed a lot of parts. Have you checked compression and your timing chain?

 

[maverickdog8]

I am checking compression when I'm off tonight. As for timing I don't want to get that deep into the motor if I don't have to.

---------- Post added at 10:15 PM ---------- Previous post was at 10:09 PM ----------

I am only misfiring on cyl 1 and 3 so I ruled out timing.

 

[Bass_Waves]

Cyl 1 n 3 are partners. May be correlated to a valve chipped or cam/crank sensor related.

 

[maverickdog8]

I'm running the compression test at 10 when I'm off. I'll post the results when its done.

 

[onedoughboy]

You can check the timing by simply pulling off the valve cover. Should take less then 20 minutes. I have seen many jump timing, usually the top chain guide is cut clean off, or the tension-er has failed. I have seen a few chipped valves on the #1 cylinder. Timing is only one you can fix, as a chipped valve is gonna require cylinder head removal. You do not need to remove the timing chain cover to check the timing. There is a mark on the crank pulley, google a picture of timing chain, set to TDC, there should be 16 links between the INTAKE DIAMOND and EXHAUST DIAMOND, and three and a half links back to the top of the valve cover(from the diamonds).

 

[YelloEye]

Cyl 1 n 3 are partners. May be correlated to a valve chipped or cam/crank sensor related.

IIRC they're linked in the ignition coil block, 1&3 fire simultaneously, same with 2&4.

 

[maverickdog8]

So I got off late and am going to try and compression test it today when I'm off.

 

[Bass_Waves]

Let us know results.

 

[maverickdog8]

Every cylinder reads within 2-3 of this. So valve issue is out of the picture.

---------- Post added at 03:52 AM ---------- Previous post was at 03:49 AM ----------

But all my plugs look like this.

 

[Bass_Waves]

Looks like fuel is not going into cyl. Those look clean. Does ur fuel pump feel like it cuts out?

 

[maverickdog8]

It feels like a misfire, but it only happens in drive. The miss may be from the fuel pump cutting out tho. The car jerks when I'm driving and acts like it's going to die. The car only has 57k miles on it.

 

[YelloEye]

You could try running some Chevron injector cleaner concentrate through it. You changed the injectors already though.

 

[Bass_Waves]

He could swap injectors around. 3 into 4 and 2 into 1.
If the misfire comes back into cyl 1&3 again then injectors are fine.

 

[YelloEye]

I like that idea.

How are the plug gaps?

 

[maverickdog8]

Running the NGK iridium plugs. I didnt gap them, but I did carefully check them with a feeler gauge and they were right on. I've swapped them around a few times checking stuff and its still cyl 1-3 missing.

---------- Post added at 04:29 PM ---------- Previous post was at 04:28 PM ----------

And the injector swap idea wouldn't help. I've put new injectors in and it still misses on the same 2 cyl.

 

[Bass_Waves]

Pull the valve cover. Check the rockers on cyl 1 and 3. As well as the cams

 

[maverickdog8]

I'm gonna have to do that either over the weekend or next Tuesday. I get off at 10 every night so its tough.

 

[YelloEye]

Well you've ruled out the combustion chamber, the valve actuation system might be off. This is odd.

 

[maverickdog8]

I'm gonna check timing and rockers on Tuesday since that's my only day off.