URS6 rev limiter 6000 RPM problem

vwnut8392 · Post by **vwnut8392** » Sun Jul 26, 2015 11:03 pm

i have a friend who just picked up a URS6 and it does the strangest thing, it acts as if the rev limiter is at 6000 RPM. the car is mostly stock less a clone MTM 1+ chip set. it seems like a slow fuel cut rev limiter, i've never seen anything like this. only thing i tried is i put my stock test ECU in the car to see if the problem would go away and it didnt. have any of you guys ever seen anything like this? previous owner said it would go to 7200RPM with no problems.

vwnut8392 · Post by **vwnut8392** » Sun Jul 26, 2015 11:08 pm

here's a VEMS log from the last pull today on my test pad. this is an easy first gear than full pull to the rev limiter before i run out of room.

i posted in the wrong thread, whoops!!!!! it was late, ignore this post with the VEMS log.

Post by **EDIGREG** » Mon Jul 27, 2015 10:05 am

Ryan has been texting me about this (I am the previous owner). You've ruled out a software/ECU issue by confirming it does the same thing with a stock ECU. Sounds to me like a trigger error... make sure the crank sensor is clean, not too far from, and has a good pickup on the flywheel. Does he still have a stock flywheel on there?

Other than that, is it possibly a misfire or fuel supply issue? The injectors were cleaned and balanced a few years ago, but maybe the fuel pump is failing?

vwnut8392 · Post by **vwnut8392** » Mon Jul 27, 2015 1:05 pm

EDIGREG wrote:Ryan has been texting me about this (I am the previous owner). You've ruled out a software/ECU issue by confirming it does the same thing with a stock ECU. Sounds to me like a trigger error... make sure the crank sensor is clean, not too far from, and has a good pickup on the flywheel. Does he still have a stock flywheel on there?

Other than that, is it possibly a misfire or fuel supply issue? The injectors were cleaned and balanced a few years ago, but maybe the fuel pump is failing?

i know it was your car. well actually the VEMS log above was meant for another post from my 4000 so just ignore that lol. i was going to check the crank sensors next. i figured if there was missing teeth on the flywheel or something it would show up on the tach so i ruled that out. like its literally a a rev limiter, its not hesitation or anything. it feels like the ECU is removing injector pulse like a rev limiter. i was thinking its something boost related because of how the car makes boost on the stock turbo IE hitting its peak boost at 6000RPM. i wonder if its ramping up too fast and its doing a light fuel cut perhaps? i know the MTM 1+ is a non linear chip set. its like gate shut, no boost, no boost, 3000RPM it hits boost really hard to 6000rpm. checked it with vag com and tried to watch some of the mesauring blocks to see if i could spot anything out of the ordinary and couldnt. i've never seen a URS do light fuel cut though, only the hard fuel cut where you almost smack your head off the steering wheel during a hard pull when it hits lol. i'll help him figure it eventually. aside from this the car runs better than most of the others around including my tired ass S6 avant. now that i say that i think this car would honestly beat the other URS4 i work on that has the same chip set with 3in turbo back and intake. that leads me to believe why there's a boost control problem which is causing it to exceed the boost limiter mapping.

Post by **EDIGREG** » Mon Jul 27, 2015 1:59 pm

I doubt it is an overboost fuel cut since it is occurring at 6k rpms on a stock turbo.

Also make sure it is in time, since he just did the head gasket the cams might be off by a few teeth?

vwnut8392 · Post by **vwnut8392** » Mon Jul 27, 2015 5:12 pm

EDIGREG wrote:I doubt it is an overboost fuel cut since it is occurring at 6k rpms on a stock turbo.

Also make sure it is in time, since he just did the head gasket the cams might be off by a few teeth?

i did the timing on both the cams and the belt and i know its spot on. i've torn apart so many 20V's and put them back together now i could set cams and belt timing with my eyes closed :lol:

.

vwnut8392 · Post by **vwnut8392** » Thu Jul 30, 2015 1:37 pm

turns out after a test with vag com the rev limiter is spot on and the tach is off by a 1000 RPM by the time it gets to 6 grand. never seen this problem before ever.

Post by **EDIGREG** » Thu Jul 30, 2015 2:21 pm

yeah he texted me last night. that is odd. I'd just swap in another UrS cluster and see if it does the same

mushasho · Post by **mushasho** » Thu Jul 30, 2015 6:01 pm

Which I have

vwnut8392 · Post by **vwnut8392** » Thu Jul 30, 2015 7:13 pm

EDIGREG wrote:yeah he texted me last night. that is odd. I'd just swap in another UrS cluster and see if it does the same

he said he'll just deal with it for now, he knows to shift at 6 instead of 7 lol.

mushasho wrote:Which I have

Thats a URS4 cluster, he would want and need a URS6 cluster with the digital mileage.

mushasho · Post by **mushasho** » Thu Jul 30, 2015 10:48 pm

I wonder if you can extract the tach portion and retrofit it into his...

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URS6 rev limiter 6000 RPM problem

URS6 rev limiter 6000 RPM problem

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Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem

Re: URS6 rev limiter 6000 RPM problem