Hello everyone, I picked up my rotary rocket a couple months ago and I've been fixing little things here and there ever since. Things were running great until last week, I thought I was noticing a loss of power up top in the revs but it took untill last night to truly notice. The car isn't making power past about 6k, and takes forever to reach 8, it will get there but not very fast.

The car has 140K, the engine has ~20k. I replaced the plugs about 3k ago. I know my main cat is rattling so I'm assuming that is the best place to start, I'm going to remove and gut it this weekend, if for nothing more than to remove a rattle until I update the tired exhaust.

I've seen some people say the coils might be going bad from some searches, is there an easy way to test them? Is there something else it might be?

 

It could be possible you 5th/6th ports are not working properly and choking the engine out, could also be secondary injectors not kicking in like they should be. Yours has the electronic actuators, and if i remember correctly they work off the air pump (not fully familiar with s5 engines), is your air pump hooked up belt wise? May also be they are carboned up and not opening fully. Vacuum leak is also a possibility, but you "should" notice that through the entire RPM range.

Easier things to check without major tearing apartis to repkace the fuel filter, and make sure your fuel pressure is up to par as well

 

Thanks for the reply, as of last month the fuel filter was replaced and fuel pressure was solid, BUT I did just complete an autocross, I may has dislodged some stuff in the fuel tank and clogged the pump sock, now that I think of it I haven't open that up yet since owning it.

Air pump is still hooked up and working, 5-6 ports appeared to be working when I was going over everything a couple months ago, but I never opened em up. I replaced the Fuel Pump Resistor Relay with a working used one.

Thanks for the suggestions, I'll hopefully find my problem this weekend.

 

Fuel sock is another possibility, and the only way you can make sure the ports are actually opening is to take the intakes off. If you got the extra cash do, pineapple sells those replacement.....doors i guess you could call them lol, and i've read alot of people on here say they are worth putting in

 

I've heard to place some grease on the rods or linkage that goes to the auxiliary valves (correct name lol) then go for a drive and recheck if the grease has been disturbed.

You also have the VDI (variable intake runner length) system, btw, also activated through air pump via relay and ECU.

 

Isn't the VDI and 5th/6th ports the same thing?