Power loss after 6k (s5 n/a)
 

Ok, I got a s5 na for 200 bucks. Looks like crap but runs great. Well runs great until it reaches just over 6k rpm. What could the problem be? It also has a bad idle so I will probably check the tps next week, I'm gonna need to get it to idle good for the smog check. This car runs really good up until just over 6k then just looses power as if it's not getting fuel anymore or something. I was really looking forward to feeling the 8k redline but guess I wont for awhile. Just changed the spark plugs and fuel filter so I know those are good.

Thanks

Soudns to me like a clogged air filter, or a clogged catalytic convertor. I would think those would create some restriction (or at least enough to not make any more power up there)

Mike D

This problem sounds like a bad Air Flow Meter to me. Pull the error codes from the ECU.

maybe it's your vdi

There are a number of things that could cause this problem. I'd look at more common things before you decide the AFM is bad.

Bad idles are usually due to vacuum leaks, TPS issues and bad/sticky BAC valves.

As for your no power, first, check to make sure that both your 5th and 6th ports and VDI are working. Both will stick and cost power. Second, make sure your (assuming) stock exhaust is not clogged.

best bet if you have some cash kickin around.. set the TPS.. get some new plugs.. get a air filter.. And if you wanna feel some decent power after 6K your gonna need a header.. os grab one of those and get a straight pipe (if your brave enough) to a single to dual whatever you like, high flow cat back..

basicly the problem is bad airflow one way or another, or the computer thinks theres bad air flow so theres alot of things really, use a diag if ya have one around, i know i sound like john madden lol.

Wow, thanks for all the speedy replies, I will let you know if I figure it out. Probably won't have time to do much until Monday.

Ignore Mephis' reply. He just parroted what I said, but with no understanding of how or why. All he does is give generic, useless answers.

Might be the vaccum line also, mine used to pop off everu now and then...

10-4

aaron you act like im some dumbass, i know your the super inteligent *i went to collage for 7 years about rotaries* person but you critize for no reason. i said that cause it could be a ton of things it could even be some carbon buildup in a port its just not distinctive.

Mephis, I am trying to prevent misinformation and post-whoring. All you ever seem to do is pollute threads that can otherwise be useful. Your advice is either entirely wrong, or just a copy of what someone else has already said in the thread. I have no problem a person who doesn't know the be-all and end-all of rotaries (becaue I certainly don't know everything...not even close), but I DO have a problem with incorrect information and pointless answers. ESPECIALLY when you take someone else's answer and then dumb it down in your reply.

i dont know about you but i dont read every post in a thread b4 i reply, i just reply with a straight anwser that would give someone plenty of things to check.
i said have a diag ran on it, because that would narrow alot of things way down and make it much less painful to go through everything chasing it down, in the end paying the money for it will be worth it.

Then perhaps you should read every post before replying? Regardles, then is getting too OT. If you want to continue this discussion, please take it to PMs.

A compression check wouldn't hurt.

could be 5th and 6th ports...thats what happeend to me...stuck ports and it would rev to redline but took forever to get up there

Would this affect the acceleration at this high of an rpm? I know the car has sat quite awhile and the previous owner probably never redlined it so the actuators could be stuck but I thought they kicked in earlier.

AMEN BROTHER!

Nobody takes the time to read anymore... There would be a lot less post whoring if we'd all just read.

my s5 did this when i first bought it solely because it hadn't been driving often. just drove it often and revved it high until it fixed itself. my guess was lodged carbon or something like that.

for the 5th and 6th ports...it definitly did, like you say it would pull fine but then it would just rev slow and felt like i was going no where at higher rpms. so to test and see if they worked i pulled the vaccum lines from the 5th and 6th actuators and drove the car...i felt no difference and thus had to get a new lower intake manifold b/c mine was so cloged with carbon buildup, they couldnt even clean it it was so bad. my mech. told me that it must have never been reved at all...which is ok by me since the engine is actually has very high compression

Well thanks for all of the valuable info from everyone! My car is fixed as far as the power loss after 6k goes. I can't tell you what it was though, it just fixed itself. Like I said, the car had been sitting for a long long time so something may have been stuck or clogged. I floored it a few more times and now it pulls hard all the way to 8k! Now it's time to work on the idle.