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The fluctuating type at idle. Where it takes few seconds for it to settle as you come to a stop. It will then slightly fluctuate as you sit at idle as well.
This oddly first came about when I first installed the ROWs and fired up the car. So I naturally assumed it was the ROWs as I’ve seen other members with similar issues running ROWs. Tuning for them didn’t help as I had hoped so it was troubleshooting time.
I swapped o2s on the LTH, no difference. Reverted back to US spec boxes, no difference. New Injectors helped but not by much.
I think that there is a possibility that my TB are getting stuck open. I did a WOT pull yesterday and the car pulled like a bull. When I let off in second as the car shifted into third, the car acted as if I was still on throttle, and a lot of it.
The fluctuating type at idle. Where it takes few seconds for it to settle as you come to a stop. It will then slightly fluctuate as you sit at idle as well.
This oddly first came about when I first installed the ROWs and fired up the car. So I naturally assumed it was the ROWs as I’ve seen other members with similar issues running ROWs. Tuning for them didn’t help as I had hoped so it was troubleshooting time.
I swapped o2s on the LTH, no difference. Reverted back to US spec boxes, no difference. New Injectors helped but not by much.
I think that there is a possibility that my TB are getting stuck open. I did a WOT pull yesterday and the car pulled like a bull. When I let off in second as the car shifted into third, the car acted as if I was still on throttle, and a lot of it.
fun times... I’m all ears.
I had a similar issue. Ironically, I installed ROW boxes. After a day or so, I noticed this funky idle. The problem became pronoinced as the engine temps climbed.
Like you, I swapped out the ROW boxes for OEM, K&N filters swapped back to OEM but still, the engine idle would oscillate. 800, 900, 1100, 1000, 900....
I checked for manifold leaks, had the engine smoke tested, check for any stored codes but nothing. With an ODBII scanner I monitored ignition timing at idle. Comfirmed it was -8 degrees when it should be in the +12 - +15 range.
In the end, removed the intake manifold, TB plate was corroded, as well as the intake manifold. Neither leak appeared during the smoke test. And since the air leak was post sensor, the unmetered air caused the idle to move around. In addition, there was a small leak at the PCV hose connection.
Replaced the parts and all is good now.
All this while wanting to get a tune from Barry. In 4 months, I fixed a plethora of parts. Now I'm ready.
It does, it sorta confirm my speculation that it might be the PCV. Even though it’s not throwing any codes, or making the PCV whistling noise that you’d hear. My TBs and the plate will need a good cleaning to say the least.
I just wish MB sold the tb plates separately, no way in heck am I spending that much on a whole manifold just to get the plate. (This is of course in any case that my plate is damaged. I’ll try to score one on ebay used if I’m lucky just to have it when i take it all apart to inspect.
I’m also putting tuning on hold for now. No point in having Barry fight it, especially if it ends up being the stupid PCV or the TB plate.
It does, it sorta confirm my speculation that it might be the PCV. Even though it’s not throwing any codes, or making the PCV whistling noise that you’d hear. My TBs and the plate will need a good cleaning to say the least.
I just wish MB sold the tb plates separately, no way in heck am I spending that much on a whole manifold just to get the plate. (This is of course in any case that my plate is damaged. I’ll try to score one on ebay used if I’m lucky just to have it when i take it all apart to inspect.
I’m also putting tuning on hold for now. No point in having Barry fight it, especially if it ends up being the stupid PCV or the TB plate.
Thanks for sharing the link. I ordered it last night after speaking with Barry as I wasn’t familiar with the company or their products. Looks like a solid piece. Now I just need to source the TBs.
PCV and leaking TB Mounting Plate will only throw a code when completely non functional so much to a point where the computer is past its ability to manage.
as far as seeing a negative on ignition timing on idle, this is a huge identifier of air leaking and the computer managing the additional air causing an increased idle by lowering ignition timing.
The “NEW” plate came in today and I was not impressed. Metal shavings/chips, obviously used and abused. Not sure if I am under the wrong impression but I wasn’t expecting this.
i would just deburr the plate on all edges with casting flash. although not perfect, leaps and bounds better than the magnesium one we have that slowly deteriorates over time due to fuel and oil corrosion.
After speaking with RMT they too agree that part should have been new.
“These parts are new, not refurbished, we are not sure why yours was like this upon unboxing but we are offering you $50. “
I kindly declined the reimbursement of $50 and asked for a new part as advertised on their web. We’ll see.
Kinda frustrated at this point with Vendors. All that is left is for fcpeuro to let me down as well. Still waiting on their parts to show up.
First it was my e85 gauge kit that was misshipped which I had to return- Now I’m waiting for the right part. Thanks for the stupid RPM clock. Now, yet again, it’s used parts when they should be new. 🤬
I take it that nobody gives a crap about quality check anymore. Just ship whatever is available I guess???
UPS was nice enough to finally delivery the TB plate. Very happy with the unit.
Last thing to source, as a back up before I take the IM apart, is TB themselves. With 53k miles it might make more sense to replace them since I’ll be taking them out anyways. I’ll also be replacing the PCV and returning back to oem filters.
Are you going bigger TBs, or stock? Might have missed it.
My plan was to remove the IM to do PCV and IM gaskets. Since the IM is coming off I want to inspect the inside, mainly the plate and the TB ls. While doing so I’m gathering parts in case I see a need to replace things.
My plan was to remove the IM to do PCV and IM gaskets. Since the IM is coming off I want to inspect the inside, mainly the plate and the TB ls. While doing so I’m gathering parts in case I see a need to replace things.
The latest TB plate is the replacement sent back to you? The first one sent was so, so in QC.
My plan was to remove the IM to do PCV and IM gaskets. Since the IM is coming off I want to inspect the inside, mainly the plate and the TB ls. While doing so I’m gathering parts in case I see a need to replace things.
I see. Sounds like the 74mm stock route then. I ask because I was wondering what difference we might see with the 82mm (or larger!) TBs while running Barry's tune, which I know you are running too.
I see. Sounds like the 74mm stock route then. I ask because I was wondering what difference we might see with the 82mm (or larger!) TBs while running Barry's tune, which I know you are running too.
I would have went with VRP’s upgraded kit had they added velocity stacks to their TBs. I don’t see myself spending $4k on Renntech just yet.
As for power, I believe you’ll see noticeable difference at lower RPM, not so much up top. This is of course my opinion based on results that I’ve seen from others. Not personally.
My current goal is to eliminate the PCV issue, crossing fingers, and finishing the car for E85. Then I’ll let my imagination run wild. I’m really just waiting for a good set of cams to come out. As my ultimate goal is to build the top end before anything else.
Car is now running stronger than ever. Now it’s back to tuning and logging. I went ahead and did bunch of preventive work ahead of time. Decided to replace the PCV, IM Gasket (obviously), TB’s Plates. That was the plan but I decided since I’m at 55k miles now, I replaced all the pullies and belts as well. Transmission mount, why not.
New look as well,
Finally made up my mind and went with Forgestar CF5V. Wrapped in PS4’s. Couldn’t be happier with the decision,
Not too shabby,
Not sure if I should join the cool kids and paint the calipers,
New Plate,
Transmission mount part number,
This guy is going in once the catch can gets here,
Car is now running stronger than ever. Now it’s back to tuning and logging. I went ahead and did bunch of preventive work ahead of time. Decided to replace the PCV, IM Gasket (obviously), TB’s Plates. That was the plan but I decided since I’m at 55k miles now, I replaced all the pullies and belts as well. Transmission mount, why not.
New look as well,
Finally made up my mind and went with Forgestar CF5V. Wrapped in PS4’s. Couldn’t be happier with the decision,
Not too shabby,
Not sure if I should join the cool kids and paint the calipers,
New Plate,
Transmission mount part number,
This guy is going in once the catch can gets here,
Sheeshh love them forgestars. what's the spec on those?
Are you having any of these issues, are any of them related to you, then read on. Will this help you fix your problem, perhaps it might.
Several months ago when I started modding my 2013 FLC63, MBH full setup, bigger injectors, etc… the usual bolt on stuff. At the time I started my tuning venture with Barry.
With no warning, and to this day, no CEL or any codes whatsoever. Bummer, right? Most people would turn around and blame their tuner, which at no point did I ever think of even brining it up. I just knew something was wrong with my car. (I owe Barry a lengthy 5 star review, those of you who have not had the pleasure, Barry is amazing).
Anyways,
I started to feel rough idle.
Not only that, but leaving off the line the car would jerk back and forth, as if it’s gasping for air. Best way to explain it is me learning how to drive a stick shift at 14 year old.
2-1 shift, f*** your neck
2-1 shift rolling to a stop felt like someone rear ending you, again, f*** your neck
2-1 shift rolling to a stop then getting back on it, well f*** your neck again
———————CONTINUED————————
I spent nearly $4-5k doing the following, like any mechanic which I’m not, it was time to trouble shoot.
We did a smoke test which didn’t show any leaks whatsoever.
At first I replaced the injectors, sparks and filters… little to no help.
Second was engine mounts and transmission mount, little to no help.
Then we took apart the IM and replaced the IM gasket, IM TB plate and the PCV valve. This helped, but the problem still persisted.
Regular boxes vs ROW boxes showed no difference,
We then replaced all the belts and pullies, no difference. (Which was expected).
At this point I’m just scratching my head. The car is a monster under WOT, but the 2-1, rough idle, abrupt acceleration from a dead atop, and coming to a stop or getting back on it was hell..
SO WHAT WAS MY FIX???
We do another smoke test and we see a very small, tiny leak on the back of the IM, where the brake booster line connects.
I ordered a new line, replaced it and car was 90% better. My heart finally starting beating at a regular pace again. Few days go by and the symptoms are back…. So what happened next?
Thanks to Kim S (IG: 63amgeek) saw my post on IG regarding the brake booster line and commented if I had replaced the O ring.
Thanks to Kim S, he provided me with part numbers for the O ring and the cap, which arrived today.
I took the car apart right away, replaced the O ring and the cap and now I’m here typing to tell you that this was my problem all along. A freaking O ring.
Yeap, **** me. I’m just happy to have finally narrowed it down.
07-31-2021, 05:09 PM
