Changed Parts. Still Misfiring!! Help Please!

[YakAttack]

14 hours ago, YakAttack said:

I will get noid light rental from O’Rielys and check each one. How do I use the mechanic stethoscope?

 

16 hours ago, sefiroxx said:

Double check the injector.

 

Noid light to confirm power. Then a mechanics stethoscope to confirm it is opening (ticking)

 

 

I went got the noid light and looks like all injectors checked out just fine. 

[diyer2]

The noid light confirms the injector is getting power.

It does not confirm the injector is working mechanically I believe.

Thus the mechanics stethoscope to listen for the injector ticking which should mean it's working.

 

If you are convinced it's not an electrical issue, then mechanical issue it is.

Maybe start wrenching.

Or dealer and let them check it out.

 

 

[Black02Silverado]

Didn't he already swap injectors to see if it would change?

 

[diyer2]

2 minutes ago, Black02Silverado said:

Didn't he already swap injectors to see if it would change?

 

Maybe.

Don't remember.

I think he starts wrenching.

 

 

[YakAttack]

2 hours ago, diyer2 said:

Maybe.

Don't remember.

I think he starts wrenching.

 

 

I swapped injectors. Swapped coils. Still get the same miss. I took valve covers off on both sides this morning. I took videos. All of the rocker arms are operating properly. No ticking coming from any of them 

[YakAttack]

3 minutes ago, YakAttack said:

I swapped injectors. Swapped coils. Still get the same miss. I took valve covers off on both sides this morning. I took videos. All of the rocker arms are operating properly. No ticking coming from any of them 

I still don’t understand why when I pull connector on cylinder 5 coil it makes no noticeable change to the engine like the other 7 do. ??‍♂️

[riverbanks]

110 compression,there is no quench

[Black02Silverado]

Just curious, but what was the compression in all the other cylinders?  Also did you squirt oil in and test again to see if there is any difference?  I know this is mind boggling, maybe a slightly bent push rod?

[YakAttack]

I will end up bringing it to the dealer on Friday and let them check it out. Tell them what I done so far and observed and see what they find. The compression check he done to it on cyclinder 5. Wish he would have at least checked out another one. I don’t have a compression gauge and he is 2 hours away. 

[riverbanks]

Sometimes you got to give in,stuff happens,as a shop owner,my advice is ,limit your advice to a shop,you can shut a mechanic down before he starts,no one wants to be told what it is or not,when you're hiring them, just beg,I'm broke and need my truck,that energizies me

[carkhz316]

I'm too late to this thread by the sounds of it, but nobody mentioned or suggested OP run some diagnostics. I am sitting here wondering what his fuel trims and O2 data is (obtaining that info you can almost always discern if it's an ignition miss, fuel miss, vacuum leak, dirty MAF, etc), and if it's a "misfire" or an outright dead cylinder (I'm guessing the latter). 110 for compression is low, typical is 175ish. You say that the rockers all move and all that, but I just replaced a broken valve spring that still allowed opening and closing of the valve, and rocker arm movement, etc, yet yielded a dead cylinder and intermittent compression. Let us know what parts stick to your truck after your dealer starts slinging at it! Also, you can substitute a noid light with an incandescent test light. Same thing sans a plug. Backprobe with some T-pins and you can confirm power and ECM control of injection, as well as coil power and ground. 

Edited February 4, 2019 by carkhz316

[YakAttack]

On 2/2/2019 at 3:07 PM, newdude said:

 

A non AFM lifter could cause a misfire, but if it is, I'd be checking the camshaft lobe for pitting and wear.  If the lifter spins the bore at all, it would eat into the lobe.  Is there any metallic squeak noises when its running at any RPM range?  Something that would follow the speed of the engine? 

For all of those who are following the post I didn’t get a chance to bring to dealer today before it was closing but was able to get a proper compression check. It got 180 psi at cylinder 1,3,5,& 7. Still when pulling just the plug in connector on coil #5 I am not getting any difference in engine sound as I do the others. Still I am getting spark from the plug on that cylinder. So we still at the confused point. 

[YakAttack]

Now the ANS light kicked on and the stabilitrak lights are staying on with it. 

[dbrieler]

Did you ever resolve this issue? I have a similar problem on #3 cylinder that has me stumped. I swapped injector, coil, wire and plug, code still on #3.

• Good compression, running test and cranking test**
• Good cyl leak down
• Check spark, ok
• Noid test OK
• Good fuel pressure 58psi
• #3 is a non AFM cylinder
• All valves are actuating, measured travel at approx. .300" intake and  exh. 
• cleaned all injectors, #3 had noticeable contamination two different times (even after cleaning and running a few miles) 
• Injector resistance (ohms) is good on all injectors

I am beginning to think it is bad fuel due to finding the #3 injector dirty after through internal cleaning but why would it only be on one cylinder? Also why doesn't it clear after cleaning? 

I first did a running compression test;

• #3 came up to approx 130-150PSI after I clear it went to zero and would not build any pressure after that. Any time I retry this it has compression at start up but then goes to zero after clearing the gauge. Other cylinders do not do this.
• Ran a cranking speed compression test with all plugs removed, this cylinder is one of the two best @185psi.
•  
• This made think a lifter was collapsing after the oil pressure came up so I removed the valve cover and ran the engine, all lifters appear to be working properly. 

 

[YakAttack]

 Never figured it out. I brought it to dealer and paid for a diagnostic test there. Compression, injectors, fuel pressure, plugs, wires, coil are all fine. All they could say was it seemed like more of in internal problem causing cylinder 5 to have that dead miss. 

 

   I was told find a shop with a scope that can look at the internals was an option. Removing the valve cover and valley cover under the intake and check for stuck lifter which I already removed the valve cover before I didn’t see or feel as if anything was stuck. Never took off valley cover. I could bring to shop and pay $3000 to install new lifters or I could take the heads off myself and inspect  it and try diagnosing what’s wrong. 

 

   I want to trade it in but with how much I owe and how much I’d get with a vehicle missing like this I def think I’d be so far upside down. 

 

  So i’m left with a decision to make