Possible Misfire, thoughts?

[uwishprod]

I did research this and found some similar stories but nothing to exact so I thought I would ask.

While parking my car yesterday, I had a special moment and released the clutch in a parking spot while in gear and while running. So car shuts off. I go into store and then return. Car starts fine and drives fine for about an 1/8 of a mile and starts to sound rough as well as very low idle when coming to a stop. Once I get to a parking lot to check my car it now sounds like it has heavy lope cams. The motor sounds like a misfire. The cab of the car reeks of fuel but no fuel leak present.

Here is a list of what we checked. Maybe someone has another idea.

* I have checked all spark plugs as well as tested all coil packs.
* I reverted the tune back to stock then back to aftermarket.
* Car does not have CEL, even under stock tune(vehicle barely runs on stock tune) no CEL present.
* Spark plugs have less then 20k miles and were swapped for one piece aftermarket ones
* Inline fuel filter has about 20k miles
* I have never had any mechanical problems with this car.

Mods done to car: Off road x-pipe, JLT intake with SCT Brenspeed 93 octane tune.

Our current plan is to pull out injectors and flow test them as well as clean fuel system. My car only has 62k miles and is barely driven now. More of a garage queen these days.

Is there a slight chance when parked I released the clutch while in gear and running that I jumped my timing somehow? I have never heard of a motor doing that but it never hurts to ask.

Here is a video of the sound. iPhone video so not top notch quality

 

[stkjock]

did you check the battery and alternator?

 

[recordbreaker5]

question...if one of your phasers broke, would it throw a CEL?

 

[Flapjack]

In my experience, jumping a tooth doesn't really affect idle much. I was off two cam teeth and the only way I could tell was a huge lack of power.

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[psfracer]

Ok, so assuming you pulled all of the plugs, did any of them look black?

For the alternator/battery, look at your battery voltage while idling. Should be around 14V or so. You can also wait till evening, turn on your lights, then use your power windows. If your lights dim, you have an alternator that is not doing its job.

 

[uwishprod]

Ok, so assuming you pulled all of the plugs, did any of them look black?

For the alternator/battery, look at your battery voltage while idling. Should be around 14V or so. You can also wait till evening, turn on your lights, then use your power windows. If your lights dim, you have an alternator that is not doing its job.

Battery is only 6 months old. Will check alternator though. Also one plug was slightly black.

Now off work and can dig into trouble shooting. Thanks everyone for advice.


Sent from my iPhone using Tapatalk while driving 120mph weaving in and out of traffic.

 

[uwishprod]

Alternator checks out good.


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[psfracer]

Ok, the plug that is black, check both wires to the COP--- i had the insulation come apart on one wire once and it made that cylinder miss. Also, if that checks out, you may want to check that injector-- if that is ok, then i would pull the valve cover real quick and check it out.

 

[uwishprod]

Found the problem. Broke a valve spring on one cylinder. Easy fix. Thanks everyone again for your help.


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[AnotherS197GT]

Found the problem. Broke a valve spring on one cylinder. Easy fix. Thanks everyone again for your help.


Sent from my iPhone using Tapatalk while driving 120mph weaving in and out of traffic.

Did the valve drop? A broken spring for me ended up costing me my engine.

 

[Flapjack]

Found the problem. Broke a valve spring on one cylinder. Easy fix. Thanks everyone again for your help.


Sent from my iPhone using Tapatalk while driving 120mph weaving in and out of traffic.

Wow. Glad you found it!

The next question would be is, do you think that happened from you stalling the car?

 

[uwishprod]

Wow. Glad you found it!

The next question would be is, do you think that happened from you stalling the car?

It is a possibility that caused it. But could have fractured the spring back in the day when I used to race it and just finally broke apart.

My only question now is, well I pretty sure I have to, but do I need to remove the cam to replace the spring? The spring is located where the cam is not in the way but I am guessing with the tension of the cam that I wont be able to slide the rocker back in.

Did the valve drop? A broken spring for me ended up costing me my engine.

Luckily when the spring broke it collapsed in itself. So the retainers still held the valve and spring kept if from falling inside the motor. Its by far a lucky scenario and could have been worse.

Here is a photo. Hard to tell but you get the idea.

 

[Flapjack]

You can change the springs without removing the cams. You'll need the valve spring removal tool and a compressor correct fitting.

Here's a link to the FSM page on spring removal:
http://iihs.net/fsm/?dir=163&viewfile=Cylinder Head.pdf

Here is a kinda crappy video on it, but you get the idea:


I have a once-used 3v valve spring removal tool if you want. I literally used it once. I can do $150 shipped, OBO:
http://www.etoolcart.com/3-valve-spring-compressor-fr-303-1039-td.aspx

 

[uwishprod]

You can change the springs without removing the cams. You'll need the valve spring removal tool and a compressor correct fitting.

Here's a link to the FSM page on spring removal:
http://iihs.net/fsm/?dir=163&viewfile=Cylinder Head.pdf


I have a once-used 3v valve spring removal tool if you want. I literally used it once. I can do $150 shipped, OBO:
http://www.etoolcart.com/3-valve-spring-compressor-fr-303-1039-td.aspx

Already rented a tool from Freedom Racing but thank you for the offer. Thanks also for the video should help when the new parts get here

 

[Flapjack]

Already rented a tool from Freedom Racing but thank you for the offer. Thanks also for the video should help when the new parts get here

No problem. Good luck!

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[uwishprod]

Found the problem. Big thanks to Freedom Racing for parts an tools.


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[HC_Tad]

I was glad to help, Noah. Now quit breaking stuff!

 

[uwishprod]

I was glad to help, Noah. Now quit breaking stuff!

I am pretty sure it will not be the last time. Good thing I have a great wife lol. Thanks again for all the help.