# HELP!!!! 2.5 Rabbit Engine Throttle hang



## pilotmd104 (Apr 26, 2008)

So i have a 2008 rabbit with a GIAC chip, EVOlution motorsports intake, and AWE exhaust. Lately around 3000 rpm when i shift, I can put my foot on the clutch and it will hold at that rpm for about 6 seconds before dropping. What oculd cause this. I thought it could be a post MAF air leak causing it to hang but that isnt the problem. Who has some ideas?! please help.....


----------



## MKVJET08 (Feb 12, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (pilotmd104)*

sounds like rev-hang to me, but the GIAC flash should have fixed that. I'd get a hold of GIAC if i were you.


----------



## p c (Oct 26, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (MKVJET08)*

only c2 and the upcoming apr flash address the rev hang


----------



## pilotmd104 (Apr 26, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (p c)*

the giac flash greatly reduced it from the factory settings, now its like a gremlin is back and worse then ever.


----------



## sagerabbit (Aug 14, 2007)

I took off my LNT CAI partially for this reason. I'll just wait till I get the C2 chip 91oct. Would disconnecting the battery do anything, like resetting the ECU?


----------



## pilotmd104 (Apr 26, 2008)

*Re: (sagerabbit)*

so you think this is from the intake instead of the chip?


----------



## SpiderX1016 (Jul 22, 2008)

*Re: (pilotmd104)*


_Quote, originally posted by *pilotmd104* »_so you think this is from the intake instead of the chip?
















Is it possible to get Revhang on a Tectonic? Well, after I installed my Carbonio CAI, it does it sometimes.


----------



## pilotmd104 (Apr 26, 2008)

*Re: (SpiderX1016)*

this is so frustrating. you spend all this money on your car and all you get from it is problems


----------



## theraudi1 (Jan 26, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (pilotmd104)*

Same prob here. I have an '08 with a VF intake and Giac 91/93 flash. With the stock intake, the "rev hang" is GREATLY reduced, but not gone completely. With the intake on, it is worse than full stock mode and it seem to come & go.
I just ordered the MAF insert and this might help the situtation. I'll report back once I get it. If not, reflashing to C2.
Rev hang is the suk!


----------



## vw93to85 (May 10, 2007)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (theraudi1)*

It's also possible that the rev hang is caused by the very heavy dualmass flywheel that is in these cars.


----------



## pilotmd104 (Apr 26, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (vw93to85)*

you think thatll wear the clutch out faster?


----------



## theraudi1 (Jan 26, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (vw93to85)*

It is programmed in to the ECU of our cars. C2 and APR have turned it off completely. GIAC "turned it down" but not off because it's tied in to the emissions of the car.


----------



## Jefnes3 (Aug 17, 2001)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (theraudi1)*

We were the 1st to get this sorted, ~2 years ago...








BTW: a CAI makes the problem WORSE for similar reason to the CEL some/most get with CAI install...

-Jeffrey Atwood


----------



## bunnyhopin (Dec 19, 2007)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (Jefnes3)*

i got the vf cai with uni stage1+ and there no rev hang here







but there is cel


----------



## pilotmd104 (Apr 26, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (bunnyhopin)*

So is my best bet putting my stock intake on or is there a way to resolve this rev hang?


----------



## MKVJET08 (Feb 12, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (pilotmd104)*


_Quote, originally posted by *pilotmd104* »_So is my best bet putting my stock intake on or is there a way to resolve this rev hang?

like everyone else has said, get flashed by c2 or APR.


----------



## _V-Dubber_ (Jan 30, 2007)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (vw93to85)*

OP welcome to Vortex and congrats on your first few posts. To help you better understand our slang, I noticed you typed EVOlution Motorsports. Evo is short for Evolution Tuning. Evolution Motorsports abbreviation is EvoMS









_Quote, originally posted by *SpiderX1016* »_Is it possible to get Revhang on a Tectonic?

Do you mean with a Techtonics* (exhaust)? The answer is yes because the reason it occurs has nothing to do with the exhaust.
The rev hang is caused by programming with the DBW system. Sometimes when you take your foot off the gas, the throttle plate inside the TB still stays open for a few moments. Even with DBW throttle response set to 9 of 9 (max), throttle response is faster but sometimes still occurs. In case you were wondering, I have REVO.

_Quote, originally posted by *vw93to85* »_It's also possible that the rev hang is caused by the very heavy dualmass flywheel that is in these cars.

No, because this also occurs with those of us with the Tiptronic, thank you very much.
Secondly, I cant tell you enough times your Retta looks fantastic dude!


----------



## elitist (Apr 18, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (_V-Dubber_)*

Get rid of the GIAC and go running to C2 for thier better flash.


----------



## dlob32 (Aug 17, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (elitist)*


_Quote, originally posted by *elitist* »_Get rid of the GIAC and go running to C2 for thier better flash.









c2 with vf intake and GHL exhaust. cant complain at all. c2+ no rev hang http://****************.com/smile/emthup.gif


----------



## darkk (Jun 22, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (pilotmd104)*


_Quote, originally posted by *pilotmd104* »_So is my best bet putting my stock intake on or is there a way to resolve this rev hang?

I would put the new intake on and get the C2 flash. no more "cel's" related to intakes/exhausts,it will eliminate the rev hang,eliminates the drive by wire lag,increases the rev limiter to 6700 rpm,I got a slight increase in gas mileage,better performance,the power range starts way earlier and goes to red line, best of all.. the over all drive ability alone was worth the money. second best of all, is the price is only $249. win-win situation.


----------



## dlob32 (Aug 17, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (darkk)*


_Quote, originally posted by *darkk* »_
second best of all, is the price is only $249. win-win situation. 

APR is 500? that to me is just ridiclious!


----------



## GT_GREG (Dec 11, 2002)

ive actually run into the same thing in the last while
i have the giac on my 08 rabbit.. and when it was first done.. it was awsome. no hang.. nothing.
did the carbonio.. still nothing
did the magnaflow catback.. still nothing.
did the neuspeed pulley and switched to the neuspeed intake.. nothing.
took all but the chip and exhaust off for the winter and now thew hang is coming and going...


----------



## sagerabbit (Aug 14, 2007)

APR just released a new package for the 2.5L. Wonder if it really gets rid of the rev hang with CAI...


----------



## [email protected] (Apr 14, 2005)

*Re: (sagerabbit)*


_Quote, originally posted by *sagerabbit* »_APR just released a new package for the 2.5L. Wonder if it really gets rid of the rev hang with CAI...

We have offered a single program at $349 and a fully loaded suite for $599.
We went to great lengths to eliminate the rev hang but I don't know if it specifically addresses an exacerbation from an intake. Does it happen with the Carbonio? We installed our full exhaust and Carbonio intake and had no rev hangs with our Software.
C2,
Is the rev hang emissions related or engine braking assist related? The cai code your were talking about is the fuel trim code that the insert for the maf corrects? And in your opinion that is what causes the rev hang too?
I'm not calling anyone out, wanted to make that clear, I like C2!, just trying to get my head around it so I make sure I understand it better and our engineering team is very busy right now.


----------



## spdfrek (Feb 28, 2002)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (elitist)*


_Quote, originally posted by *elitist* »_Get rid of the GIAC and go running to C2 for thier better flash.









I have been thinking about dumping GIAC for C2 because the rev hang is so bad with my VF intake.


----------



## [email protected] (Jul 29, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (spdfrek)*


_Quote, originally posted by *spdfrek* »_
I have been thinking about dumping GIAC for C2 because the rev hang is so bad with my VF intake.

You're always welcome to try out our newly released software. It's available as a free trial. If it works better than what you currently have, you can pick it up from us pretty easily. If not, no worries since it's free to try.


----------



## dlob32 (Aug 17, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (spdfrek)*


_Quote, originally posted by *spdfrek* »_
I have been thinking about dumping GIAC for C2 because the rev hang is so bad with my VF intake.

do it! c2 an vf are a perfect combo trust me you will have so much more fun driving your car! http://****************.com/smile/emthup.gif


----------



## theraudi1 (Jan 26, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (spdfrek)*

UPDATE ... with the MAF insert, rev-hang is at a min. Again, this is on an '08 with with GIAC and VF intake.


----------



## Morridin19 (Nov 24, 2008)

*FV-QR*

the APR flash address all the rev hang on my car, not to mention I am getting better fuel economy too (about +2 mpg on average)


----------



## [email protected] (Jul 29, 2008)

*FV-QR*

Dude Awesome!


----------



## Audi4u (Jun 29, 2002)

*Re: ([email protected])*


_Quote, originally posted by *[email protected]* »_

C2,
Is the rev hang emissions related or engine braking assist related? The cai code your were talking about is the fuel trim code that the insert for the maf corrects? And in your opinion that is what causes the rev hang too?
I'm not calling anyone out, wanted to make that clear, I like C2!, just trying to get my head around it so I make sure I understand it better and our engineering team is very busy right now.

I am in no way answering for C2motorsports, I am just updating you with the info that has been floating around for years. 
I would not consider the rev hang issue as emissions related OR engine braking assit. Reason is the throttle hands because the throttle doesnt close all the way(right away) when the drive lifts off the pedal. That in turn causes the engine to not enter vaccum which in turn causes the injectors to keep spraying fuel. Not so good for emission. As far as being engine braking assist I don't see that either for the same reason as above because of the delay. IMO the delay gives driver the ability for a smother shift in their normal commute. 
The cai code is fuel trim code that the insert fixes, the code has been around for a while the "insert" fix, a few months. 
The cai CEL and rev hang are not related. The rev hang is magnified when a cai is added. 
I know you guys are busy and I'm sure that's the reason you forgot to mention GIAC, REVO and Unitronics in your "not calling anyone out" post.
I have no issues with APR, It's just funny that after emails, calls and even personal conversations with APR at waterfest, it took 3 years to make a code for the 2.5 I5 engine after a was told there is no market. And then "try not to call out" the one company that actually listened to user complaints and tuned accordingly.


----------



## [email protected] (Apr 14, 2005)

*Re: (Audi4u)*


_Quote, originally posted by *Audi4u* »_
I am in no way answering for C2motorsports, I am just updating you with the info that has been floating around for years. 
I would not consider the rev hang issue as emissions related OR engine braking assit. Reason is the throttle hands because the throttle doesnt close all the way(right away) when the drive lifts off the pedal. That in turn causes the engine to not enter vaccum which in turn causes the injectors to keep spraying fuel. Not so good for emission. As far as being engine braking assist I don't see that either for the same reason as above because of the delay. IMO the delay gives driver the ability for a smother shift in their normal commute. 
The cai code is fuel trim code that the insert fixes, the code has been around for a while the "insert" fix, a few months. 
The cai CEL and rev hang are not related. The rev hang is magnified when a cai is added. 
I know you guys are busy and I'm sure that's the reason you forgot to mention GIAC, REVO and Unitronics in your "not calling anyone out" post.
I have no issues with APR, It's just funny that after emails, calls and even personal conversations with APR at waterfest, it took 3 years to make a code for the 2.5 I5 engine after a was told there is no market. And then "try not to call out" the one company that actually listened to user complaints and tuned accordingly.











I appreciate your explanation.
To reply to your last paragraph:
I'm pretty sure we released the first performance product ever for the 2.5l or pretty close anyways with our Carbonio Carbon Fiber Intake. It was definitely the first to market that didn't cause a cel.
As far as the info we gave you regarding our plans, things do change sometimes and I think its better that noone was waiting a long time for our ecu upgrade if I had told them back then we were working on it. We weren't working on it nor did we have plans to. You can't be upset with us because we didn't jump full force into the car you decided to purchase. It just wasn't in our R&D plans at that time.
I have no issues with C2 at all. I was just trying to have a friendly technical debate, that's my only goal. Sure, I go on campaigns against lesser companies sometimes because they trick us enthusiasts into thinking they have great parts but I don't consider C2 to be that way at all.
C2 is well versed in engineering disciplines and processes and its refreshing to see someone else in the industry that thinks in a similar way to APR. Props to C2 for identifying a lesser supported engine and developing for that platform.


----------



## Audi4u (Jun 29, 2002)

*Re: ([email protected])*

Keith, I very much respect you taking to time to respond. 
I would love to view or participate in a technical debate. That's the reason I scan only the technical forums on vwvortex and other sites. 

As far as this statement: * "You can't be upset with us because we didn't jump full force into the car you decided to purchase. It just wasn't in our R&D plans at that time."*
I was actually play "2.5 forum advocate". By that I mean I listened to the requests of the users via emails, pm's, or phone calls and tried to "sell" the ideas to manufactures to see if it would be possible to get them on board to develop products for the 2.5 engine.
I was actually not looking for anything for myself at the time. (even though i did inquire about a special code to allow my throttle body to stay open, to be able to run my standalone past 6500rpms







)
It was mostly for the users.
And again, I have NO issues at all with APR. http://****************.com/smile/emthup.gif


----------



## chilipad (Jan 6, 2007)

I got an email at least a year ago from APR telling me the flash was coming soon. And correct me if I'm wrong but isn't Carbonio a Canadian company?


----------



## theraudi1 (Jan 26, 2006)

*Re: (Audi4u)*

Good info to know. When I got my GIAC flash at WF, they told me that the "rev-hang" was an emissions thing and that's why they lowered its effect but didn't turn it off.
The point of my orgional post was to help the guy above that had GIAC flash + VF intake and was having issues. I too had both and with out the MAF insert, the rev hang effect was increased greatly! Not sure why but the VF intake running lean seemed to make the revs hold longer and jump a bit. It was random too. Sometimes it would hold 3 to 5 secs and sometimes 1/4 sec. With the OEM cover/intake back on, all issues went away. I even switched both a few times and turned the GIAC flash on and off with both to make sure I wasn't crazy ...








Now with the MAF, the GIAC on Pump and the VF back on, rev hang is at a min (like the orgional flash with the OEM intake). Not gone completely but very driveable. Too bad GIAC couldn't have just fixed this with programming.


----------



## vw93to85 (May 10, 2007)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (_V-Dubber_)*


_Quote, originally posted by *_V-Dubber_* »_
No, because this also occurs with those of us with the Tiptronic, thank you very much.
Secondly, I cant tell you enough times your Retta looks fantastic dude!


Hahaha, A month later I check back on this thread. Thanks Man. Although I may need to put a plate on it somehow, The cops are really bustin my stones lately. I like the hideaway plate system but i'm worried I'd leave half of it in my driveway. 

Anyways back to issue of rev hang,
With my Revo Flash even with CAI, my rev hang was greatly reduced. But I still feel that with a lighter flywheel and an underdrive pulley it would wipe out the rest of the rev hang


----------



## elitist (Apr 18, 2006)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (vw93to85)*

C2 C2 C2 C2
and APR for the cars C2 doesn't make things for.
That is all.
Cheers, yo.


----------



## pilotmd104 (Apr 26, 2008)

*Re: HELP!!!! 2.5 Rabbit Engine Throttle hang (vw93to85)*

Is anyone experiencing these problems? I understand C2 and APR are what people are saying, but the reality is, I have GIAC with EVOMS intake and a AWE exhaust. What can be done with what I have to solve this.....


----------



## vince557 (Feb 18, 2006)

*FV-QR*

i still got my rev hang on my auto rabbit and i have unitronic stage 1+ and the LNT CAi


----------

