top end hesitent

JohnP · May 18, 2007, 11:31:10 PM

i could be over paranoid, but my car feels hesitent between 6500rpm-top end. Infact it almost feels rough.

is this normal? the engine is smooth as a nut between 0-6500rpm. It almost feels like vibration through the transmission? but why only at top end.. also, i\'m aware i probably need new rear suspension bushes. could the vibration be caused through play in these? and has anyone else had these symptoms?

JohnP · May 19, 2007, 01:52:41 PM

ideas guys?

anyone live around here in northants?

interloper393 · May 19, 2007, 01:57:19 PM

possible the engine mounts? diff mounts? just guessing but maybe worth a look bud

JohnP · May 19, 2007, 02:12:39 PM

i\'ll bend my back nd have a look next time i get a chance.. had another thought wether it could be clutch centre bearing.. but again i\'d expect that to play up constantly not just at the top end..

scratchies · May 19, 2007, 03:47:02 PM

its pos that you have got a plug going down on one rotor, have you got the same plugs in leading and trailing coz mine had something like that long time ago

JohnP · May 19, 2007, 11:16:35 PM

how do i go about testing which plugs at fault? or should i just replace the lot? and are the plugs positioned strangely cos of the rotary setup? sorry, i\'m a new boy to rx7 ownership.. reading reading and doing more reading on this forum to get to the bottom of my minor probs!

Jim_rx7 · May 20, 2007, 12:20:12 AM

plugs are on the rhs of the engine (on the side of it) if looking at it from the front.

Not the easiest things to get out, but hey... if I can do it!

Take the elbow of and tackle them from above. Easier imo than trying from underneath. Well, unless you\'ve got a pit/ramp.

tezz12345 · May 20, 2007, 09:07:33 PM

i can whip all for plugs out in 20 mins
but maybe i am showing off ha ha
just jack it up and get under it

RemarkLima · May 20, 2007, 11:02:19 PM

If you don\'t know when the plugs have been changed you may as well change them... And do the oil while you\'re at it too

mpk490p · May 21, 2007, 07:07:10 AM

im near wellingborough, but affraid i have a FB not a FD but may plugs and oil change will be the same

Mark

JohnP · May 21, 2007, 10:35:25 PM

i\'ve already bought oil and filter.. the cars pretty much stock so i\'ve gone with fully synthetic ester stuff... is it 4litres for an FD?

how close do you live to wellingborough?

JohnP · May 21, 2007, 10:37:47 PM

oh...what plugs do i need :Laugh went down wilpoo carmaster and my car wasnt in their plugs list =/

Red Leader · May 22, 2007, 08:21:14 AM

I\'ve got the same problem. Above 6k.
It was picked up after my rebuild run in time. At the time it was very bad, as if you were coming on and off the power. Turned out the cat was breaking up. Replaced it was a used one and its a lot better now. It\'s thought that replacing the backbox will cure it.
The gays a Hayward :Thumbsup! picked it up on a test run, above 6k the exhaust sounded rough (not flowing right). Before the cat problem was found ignition was highlighted as a possible problem so i will still replace all the HT leads as same push on easier that others.
I also replaced all the check values which has helped but only slightly.

JohnP · May 22, 2007, 10:39:35 PM

well i\'m gonna go with plugs first as i do have a slightly jumpy idle... more of a tiny missfire. it sjust strange how it doesnt affect the car between 0-6k, then its like something just starts vibrating.

Red Leader · May 23, 2007, 08:58:51 AM

Let me know if that cures the problem.