Rough at 4K - Toyota Nation Forum : Toyota Car and Truck Forums

Bwah MR2 GT · 06-17-2008, 03:25 AM

Newbie here, hi all. Great site.

Just going to run the situation past everyone in case it is a well known issue-

Recently the beast has been suddenly running "rough" at 4k on the tacho in every gear. Hit 4 K and suddenly vibrates and sounds harsh and out of time.

I did a basic service on the wk end and found oil on the tip of the lead into cylinder 1. THat does not seem good.

The residue on plugs was very black (carbon=oil i suspect)

First thing I'm going to do is replace leads, cap, plugs. Does anyone have a preferred supplier for parts? I'm in Melbourne Australia - can always get it shipped in I guess so any advice welcome.

In regards to the 4 K - the K&N seems filthy (though I cleaned it 2K ago) so might be an air retardation issue? Runnin CT20b so really starts to kick in at 4K and would need a heap of air.

ALso - any chance it could be the clutch slipping? Any way to test the slip? I dumped it the other day to check but grabbed ok off the line (not great but OK)

ANy feedback appreciated.

CHeers,

Bwah MR2 GT · 06-22-2008, 10:52 PM

As indicated in the IRIDIUM thread, this issue is now sorted - it cost me under $100. Happy times.

I cleaned and oiled the filter and replaced the plugs with Iridums.

It is absolutely flying now - in fact, running the best I have ever had it.

Could not source leads and cap in time, so just did the basics and the roughness and harsh sound is completely gone and I am smooth to 5.5K when the secondary fuel dump kicks in, and she takes off again.

CHeers,

Dreams0099 · 06-23-2008, 07:02 PM

Easy way to check clutch is to put it in 5th when stopped and let the clutch out slowly and try to keep the RPMs at about 1000, it should bog the motor rather than stay the same RPM. The more the bog and the quicker it bogs down the better the clutch. If it is easy to keep at 1k RPM with the clutch mostly out then it's toast.
As for the lag at 4k RPM, it could be from insufficient grade gas, like not running Premium Unleaded or something higher.
EDIT: Or it could be the plugs :P

Bwah MR2 GT · 07-09-2008, 02:26 AM

Ta for the clutch test - it's simple and effective.

It boggeed down quite quickly and I am satisfied I have more life in the clutch yet!!!

Car still running well. Have a Blitz Access computer now - but need to get it tuned. Good times ahead I hope...

Cheers