Misfire Counts On All Cylinders

[Fat_Joe]

Well.... I just picked up my car yesterday. And unfortunately they were unable to find out what was causing the issue. They were able to see that it was in fact misfiring on the highway and idling but they checked everything on the car without tearing the engine apart. Good news, compression on cylinder 4 which has the most misfires is good . So the engine isn't destroying itself but it's just unfortunate that the root cause of the misfire can't be found.

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[Fat_Joe]

It's been through 3 shops already and 2 tuners. The mystery still goes on. I hooked up forscan and manually turned on the imrc's And I could see them open and close along with the short fuel trims on both banks go up and down depending on whether they were open or not. (They go up when the imrc's are open and back down when I close them via forscan) So they appear to be working correctly, unless they are not closing all the way??? But the same misfire issue would happen on the old intake manifold.

 

[smokescreens]

Mine recently started to have a odd stumble at idle. Seen a that dealers were told to cycle the cam chain tensioners incase something clogged them. I have no CEL's though. Im thinking its most likely i have a slight vacuum leak.

 

[Torinate]

Mine recently started to have a odd stumble at idle. Seen a that dealers were told to cycle the cam chain tensioners incase something clogged them. I have no CEL's though. Im thinking its most likely i have a slight vacuum leak.

Did the dealer do maintenance on the cam chain tensioners? Did it help?

 

[Soulja4187]

It's been through 3 shops already and 2 tuners. The mystery still goes on. I hooked up forscan and manually turned on the imrc's And I could see them open and close along with the short fuel trims on both banks go up and down depending on whether they were open or not. (They go up when the imrc's are open and back down when I close them via forscan) So they appear to be working correctly, unless they are not closing all the way??? But the same misfire issue would happen on the old intake manifold.

Have you tried going back to stock to see if the issue goes away?

 

[smokescreens]

Did the dealer do maintenance on the cam chain tensioners? Did it help?

Have not gone to the dealer yet. Just doing some research. I really dont like people working on my cars so if i cant find a vacuum leak or the reason for the stumble the shop is my last ditch efforts. Mine just sprung up in the last 2 weeks and i havent had a chance to look into it due to work.

 

[Fat_Joe]

Have not gone to the dealer yet. Just doing some research. I really dont like people working on my cars so if i cant find a vacuum leak or the reason for the stumble the shop is my last ditch efforts. Mine just sprung up in the last 2 weeks and i havent had a chance to look into it due to work.

Does your misfire on the highway? And yes, keep us updated with what you do

 

[Fat_Joe]

Have you tried going back to stock to see if the issue goes away?

Unfortunately, I bought the car with most of the mods already installed. The only performance mod I did was the bigger fuel injectors and the 2021 intake manifold along with the tune of course. I could revert those back but it was doing the same thing on the stock manifold. The runners moved by hand, I didn't get the change to see if the actuators were working or not. I guess I could swap it back into the car and send the command via forscan to open the imrc and see if they move. But I did verify that that imrc's move on the 2021 intake manifold

 

[smokescreens]

Does your misfire on the highway? And yes, keep us updated with what you do

Im not even positive its a missfire. More of a stumble at idle. Seams to the highest chance is when the clutch pedel is depressed or right after a rev all be it a small one.

I will try and take a video of it. I havent noticed anything while rolling. I kind have a feeling its a vacuum leak more than anything. but its odd that after the stumble its smooth as glass.

 

[Basspro302]

Pull the cats out i bet one is broken away and is tilting side ways randomly causing misfires. Does it misfire wide open throttle?

 

[bankyf]

Mine recently started to have a odd stumble at idle. Seen a that dealers were told to cycle the cam chain tensioners incase something clogged them. I have no CEL's though. Im thinking its most likely i have a slight vacuum leak.

I believe you are referring to the actuator solenoids. Cycling the cam chain tensioners would be very odd.

 

[Fat_Joe]

Im not even positive its a missfire. More of a stumble at idle. Seams to the highest chance is when the clutch pedel is depressed or right after a rev all be it a small one.

I will try and take a video of it. I havent noticed anything while rolling. I kind have a feeling its a vacuum leak more than anything. but its odd that after the stumble its smooth as glass.

Ah I see. Yeah I do notice that I get a hesitation when I try to accelerate fast sometimes

 

[Fat_Joe]

Pull the cats out i bet one is broken away and is tilting side ways randomly causing misfires. Does it misfire wide open throttle?

I was thinking it could be the cats but unsure at this point. It doesn’t misfire wide open throttle

 

[Basspro302]

So it’s probably not the cats then

 

[Fat_Joe]

Well I gave in and bought 4 vct solenoids. Going to install them sometime this week

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