Persistent Idle Misfire

[SheepDog]

Not once have I said this is a tune issue. I don't know why every body keeps saying that.
I guess people are used to guys blaming the tuner, I'm not.
Lol
My original post is asking people if they've had misfires that were fixed by other fixes. Like evap or other ways, cause I and the guys at the shop I use can't figure it out. Matter of fact the shop is saying live with it.
But a car that does this is unreliable to me.

As previously asked: Did this begin as soon as you installed the Whipple, or did it used to run correctly and only recently started having issues?

The reason Im asking is, you or your shop (whoever installed) may have damaged something during installation. For example, what if there is a pinhole leak in one of the cooling bricks, and during Idle the supercharger coolant is being sucked into the cylinders and causing a misfire, but under WOT or part throttle the tiny leak is consumed by the engine without notice. What if there is something wrong with the bypass valve, causing some sort of lean condition at Idle? How about VVT issues? What do your logs at idle look like?

I mentioned the tuning thing, because you are the one who initially said you went with 2 different tuners trying to resolve the issue, and aparently burned the bridge with both of them, so you too thought it was the tune originally.

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[HKusp]

I have the gen 5 whipple stage 2 with 150mm throttle body and id 1050x inj.

I don't know who you're talking to. I am running a Whipple 132MM TB.
And I have a return style fuel system.

I am sorry I saw the above post, was reading all the posts and responded to him.

 

[Daryl333]

I am sorry I saw the above post, was reading all the posts and responded to him.

No problem, this thread has gone kind of off track. Thx for trying.

 

[Daryl333]

As previously asked: Did this begin as soon as you installed the Whipple, or did it used to run correctly and only recently started having issues?

The reason Im asking is, you or your shop (whoever installed) may have damaged something during installation. For example, what if there is a pinhole leak in one of the cooling bricks, and during Idle the supercharger coolant is being sucked into the cylinders and causing a misfire, but under WOT or part throttle the tiny leak is consumed by the engine without notice. What if there is something wrong with the bypass valve, causing some sort of lean condition at Idle? How about VVT issues? What do your logs at idle look like?

I mentioned the tuning thing, because you are the one who initially said you went with 2 different tuners trying to resolve the issue, and aparently burned the bridge with both of them, so you too thought it was the tune originally.

Thought I already answered this somewhere, but anyway. Yes issues started at install.
Plan is when weather gets better to tear it all down and start from scratch new tune, new installation. Supposedly logs are all good but one person has said that they could have probably spent more time refining the tune. So could that be it? Maybe we'll see. Also used a boroscope on all cylinders and they were all dry free of any moisture. VVT? That is something I will have to research as I didn't know they could cause such a minor issue with no codes being thrown.
But any chance of refining this tune is history. Will be getting a new tune from scratch when the weather is a bit warmer.
Months ago I switched tuners to confirm the glitch. This post was asking for mechanical solutions which you have helped with your last comment. We will be going over everything with a close eye in the spring.
So thx for your ideas.

 

[CrazyHippie]

Was just reading another thread about low battery voltage causing similar probs that were helped by disabling the battery management system. Apparently, the BMS reduces charging voltage to prolong battery life and voltages below 13.5 or so can cause similar issues. Probably a long shot?

 

[Daryl333]

Was just reading another thread about low battery voltage causing similar probs that were helped by disabling the battery management system. Apparently, the BMS reduces charging voltage to prolong battery life and voltages below 13.5 or so can cause similar issues. Probably a long shot?

I've been monitoring voltages and Battery voltage is normal.
Thx for the reply.

 

[Daryl333]

Update: Installed the Radium inline Fuel Damper. Only change was now I can see the Tach fluctuating slightly which wasn't happening before. Radium guy said: since fuel system is performing better, anomalies will be more enhanced. I don't know what to say about that one.
Anyhow now my Whipple 132 Throttle body is now popping at intermittent times.
Sometimes in tune with misfire other times not.
Also never thought this an issue but throwing it out there. Throttle body also howls or a really low toned whistle at idle. Can hear it with the hood closed. Have cleaned and inspected TB and intake assy.
I've read that stock TBs have been replaced due to popping but can't find anything in a search about Whipple TBs popping.
Anybody hear of this with the Whipple TB?

 

[ZXMustang]

Update: Installed the Radium inline Fuel Damper. Only change was now I can see the Tach fluctuating slightly which wasn't happening before. Radium guy said: since fuel system is performing better, anomalies will be more enhanced. I don't know what to say about that one.
Anyhow now my Whipple 132 Throttle body is now popping at intermittent times.
Sometimes in tune with misfire other times not.
Also never thought this an issue but throwing it out there. Throttle body also howls or a really low toned whistle at idle. Can hear it with the hood closed. Have cleaned and inspected TB and intake assy.
I've read that stock TBs have been replaced due to popping but can't find anything in a search about Whipple TBs popping.
Anybody hear of this with the Whipple TB?

Maybe thermal related. Some have reported issues with the 132 when it gets heat soaked. Guy on FB makes this thermal spacer for $75. Might be worth a try.

 

[HKusp]

If it's howling, that indicates a leak and you're hearing the air passing by the gasket, which would also give you the symptoms of a vacuum leak. Un-metered air is getting into the air inlet post MAF. Pull that TB and inspect the gasket. If it looks good, re-install and torque to 70 in/lbs. Personally I would replace that gasket even if it looks good.

 

[ZXMustang]

Are you using an open air intake.

 

[GregO]

Radium guy said: since fuel system is performing better, anomalies will be more enhanced. I don't know what to say about that one.

It's not a batch fired system so was the damper really needed ?

Also never thought this an issue but throwing it out there. Throttle body also howls or a really low toned whistle at idle. Can hear it with the hood closed.

Air moving pass the TB blade at low throttle settings will do that.

 

[Daryl333]

Are you using an open air intake.

No it's a closed box.

 

[Daryl333]

It's not a batch fired system so was the damper really needed ?

Air moving pass the TB blade at low throttle settings will do that.

Who knows if it was needed.
But my symptoms matched what some guys said was their problem.
No I know.
Whipple asked for an idle log so am doing that. They're more help than my tuner was.

 

[GregO]

Whipple asked for an idle log so am doing that. They're more help than my tuner was.

Interested to hear what Whipple has to say.

 

[Rsrfan]

Here’s a long shot…. I had persistent low rpm misfires on my Roush blown car and threw parts at it to no avail. It ended up being a small crack in the plastic one way valve running in between the supercharger and my JLT catch can. I replaced the hose assembly and valve and the misfires are gone. Might be worth a look…

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