Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: redgti on January 29, 2010, 08:02:56 PM

Title: fc running a little rough
Post by: redgti on January 29, 2010, 08:02:56 PM
just bought an fc, it seems to be in ok condition starts no problem hot or cold. however when i sit with it on the drive and rev it say to 3000 rpm as the revs are falling it seems to be missing slightly. i will be ordering new plugs and leads and give it a full service.
 
anyone have any ideas what could be causing it. Also noticed there is a missing earth that should be on the bulk head, possibly to the inlet manifold.
Title: fc running a little rough
Post by: m1tch on January 29, 2010, 08:11:48 PM
Its probably the hesitation between the primary and secondary injectors firing, there is a crossover point where the secondaries ramp up and the primaries drop down at about there.

A full service is always good :) but also check for air leaks in the long rubber inlet pipe for any leaks underneeth which might cause it to miss slightly.
Title: fc running a little rough
Post by: redgti on January 29, 2010, 08:18:59 PM
would that crossover still happen when it is revving in neutral? i haven\'t actually driven it yet mate, because its not mot\'d.
Title: fc running a little rough
Post by: TiddlesRX7 on January 29, 2010, 08:45:18 PM
Yeah a full set of plugs and or leads never goes amiss. Plus oil change etc etc.
Title: fc running a little rough
Post by: m1tch on January 29, 2010, 08:57:01 PM
What plugs and leads are you going for? I changed mine for some manicor ones off Mazda Rotary Parts, I actually felt a difference in the power output as there was a proper spark :D
Title: fc running a little rough
Post by: Brett on January 29, 2010, 09:09:21 PM
Hmmm... if the miss is on the run down (presuming throttle closed?) then it\'s going to be something other than the injector cross over (which is around 3700 iirc) - is it constant, or just the odd miss as the revs drop?
Title: fc running a little rough
Post by: redgti on January 29, 2010, 09:48:34 PM
it just kind of judders and if i tap rapidly on the throttle i get some real good cracks and pops out of the back should have said its a standard egi.
Title: fc running a little rough
Post by: m1tch on January 29, 2010, 09:51:07 PM
Might be the TPS (throttle position sensor) that might be off slightly, I know mine was, meaning that when the throttle is closed, the sensor thinks its slightly open, so increases the fueling
Title: fc running a little rough
Post by: grinder on January 30, 2010, 12:06:00 PM
i have to admit i have ran magnacor leads on my last 2 FC\'s and they are very good - only downside - they arent cheap :(
Title: fc running a little rough
Post by: m1tch on January 30, 2010, 03:07:44 PM
Quote from: grinder;668864i have to admit i have ran magnacor leads on my last 2 FC\'s and they are very good - only downside - they arent cheap :(

They are above Grinder price! But they are worth it, you only need to buy one set :)
Title: fc running a little rough
Post by: redgti on January 30, 2010, 04:09:50 PM
ok i\'ll look in to it. Grinder are you interested in the wheels i have on it??
 
(http://i98.photobucket.com/albums/l279/jamesfletch/DSCF4292.jpg)
 
send me an email on sidekickdmr@aol.com (sidekickdmr@aol.com) and i will sort more pics for you if you want.
Title: fc running a little rough
Post by: grinder on January 30, 2010, 05:53:06 PM
depending on the price - yeah im interested in them

on the laptop at the mo - so no email client installed

but drop me an email at ... admin at fc3s dot co dot uk with a rough price and what condition they are in

cheers

Stu / Grinder
Title: fc running a little rough
Post by: m1tch on January 30, 2010, 06:07:19 PM
Quote from: grinder;668938depending on the price - yeah im interested in them

on the laptop at the mo - so no email client installed

but drop me an email at ... admin at fc3s dot co dot uk with a rough price and what condition they are in

cheers

Stu / Grinder

They looks pretty good when I saw them the other day when he picked up his seat, although it was dark :rollin but the car looked well looked after so the last owner would have looked after the rims as well :)
Title: fc running a little rough
Post by: grinder on January 30, 2010, 06:14:26 PM
cool

my pc had now decided it wont boot :(

so can you email me at chojin22 at yahoo dot com

if the tyres are ok then i will be very tempted - my wheels are a bit rough - but has practially new rubber all round ( 205 front and 225 rear )
Title: fc running a little rough
Post by: redgti on January 30, 2010, 08:51:00 PM
will email you with pics tomorrow if i can get some cheers mate.
Title: fc running a little rough
Post by: grinder on January 31, 2010, 08:48:02 AM
no probs :D