Losing Power HELP!!!!
 

Hi Guys,

About a month ago, my poor RX8 would not do over 90mph. So into the garage she went. They said they could find nothing wrong and that the road test was fine, but replaced the sparks and reset the computer.

Amazingly the car was OK for a couple of days, but then slowly the power loss started to come back. When the car is cold its fine, as it warms up it gets worse. Its no where near as bad as it was, but there are two noticable gaps in power.

The first is in third at about 6000rpm to 6500rpm, a kind of 'flat' spot. The second is at the top of the RPM range (in all gears), 7000 - 9000rpm, I dont know about everyone else, but my RX8 had a 'kick' at that top range of extra acceleration. Thats gone.

When it would not go over 90mph, the engine was making tonnes of noise but producing no power - and now it revs correctly but im so sure its down on power.

to cap it all off, I took it back again to the garage - they said no fault found, however replaced oil/fuel/air filters. they also checked the 'cat'. Then im driving home from work, and the idiot who worked on my car had not replaced or tightened four bolts holding a bracket under the car. BANG and tonnes of noise later im dragging along a 10" piece of metal.

Im just about to give the garage some grief about the plate, but what do you guys think about my fault?

Thanks

Dave

Its not your fault they did not tightened the 4 bolts. That was the ass monkey at the dealer. But I cant help ya on the other probs ya got going on there. I dont have a MT and I dont get her up to 90 much. Hope all gos well. Let us know what the turn out is

Lol, I said what did you think of my fault. Not do you think it was my fault!!!

Cheers


DB

Ahh ok. I'll blam it on the time. Its 1:45.am where I am. Its the sandmans fault

I think he is asking what we think about his lack of power problem.

Sounds like bad coils. I had similar losses up top. Removed one of the coils and the potting was discolored (burnt). Had them replaced (as well as the spark plugs), all is well.

It's starting to look like coils may be an issue with our cars but I'm not raising a warning flag yet.

BTW, time to dump that dealer AFTER you get a replacement part. Good luck.

I had minor power stumbles for years which finally set a light and turned out to be a cracked intake manifold particularly the T junction right by the oil filter. It must have been damaged by a change at some point. Just because a car hasn't set a light doesn't mean that it doesn't have a problem. The mechanic is lazy. Keep taking it back until they fix it.

top gear magazine mentions that when buying used, you should be careful with sticking second stage breathing actuators (whatever that is) and that the car with a problem like this will lack power over 6000 rpms, so it might be that too.

Can a Mod move this to the "issues and problems" conference?

I think we can better address this issue there.

done

now what fell off your car? and what did they do to check the cat? did they actually drop it and look inside?

Zoom44,
Theres a brace under the car that you have to remove if you want to take the cat off. Its held on by 4 bolts. I think that is what he is referring to.

I really doubt its your stock cat thats causing the problem. BTW, why are you going to a garage and not the dealership? You should still be under warranty coverage. What sort of mods do you have that may void warranty?

Have the dealer look at your car, and specifically your coils... its a simple fix, and doesnt take too long to diagnose. If the dealer won't give you coverage on the coils (which i doubt would happen), there are some DIYs on this board that can show you how to do it.

-hS

Loss of power, well my first loss of power happened when my coils went sour, two of them were out but i changed all of them at 18000 miles . Also changed the plug cables and a new battery. As someone here said before....it might be your coils.

Thanks for the replies guys, Yes it was one of the braces that fell off. I went ape at the dealership (not garage sorry) and made them do a 70 mile round trip to come and fix the car as i refused to take it to them. Thats sorted now, but im still a little down on zip.

At the top end of the revs, 7000-9000 does everyone else have an almost 'turbo' kick of extra acceleration? Thats what mine used to have, but no longer has. Difficult to say if the car is the same speed or not, it just 'feels' slower, which is difficult to quantify but its fairly obvious to me.

Looks like Coils are my best bet to look at first, any pointers to threads on here that will let me check them out first? The car is still under warrenty and has no mods on it. But continuously taking it to the dealership is a pain, especially when they dont put it back together again!

check the first pic in this thread https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/diy-aem-twin-fire-cdi-ignition-install-88846/

I'm curious if this is an intake problem. The high end power he refers to missing at high RPM may be the VFAD or the APV motor.

How many miles are on this vehicle?

Maybe a stuck VFAD or a stuck port?