Mazda Rotary Club

Cars by Model Type => 1st generation RX-7's => Topic started by: captainbizzaro on January 25, 2008, 08:02:26 PM

Title: Cold Idle fun and games
Post by: captainbizzaro on January 25, 2008, 08:02:26 PM
Hi all, I\'ve been having to use Neville as a run about for the past couple of weeks while my DD has it\'s gearbox sorted and I seem to have lost any sort of cold idling function. He starts first time every time whether cold ,hot or indifferent......idles lovely after around two minutes of driving it\'s just the initial first couple of minutes he won\'t idle at all unless the revs are held a smidgen higher with the accelerator pedal.

The choke part of the equation appears to be working okay so anyone got any ideas, I\'m getting fed up with having to heel and toe at traffic lights!

By the way.........1983.......Series 2.........12A everything standard apart from header and air pump removed.
Title: Cold Idle fun and games
Post by: mpk490p on January 25, 2008, 10:47:50 PM
Quote from: captainbizzaroHi all, I\'ve been having to use Neville as a run about for the past couple of weeks while my DD has it\'s gearbox sorted and I seem to have lost any sort of cold idling function. He starts first time every time whether cold ,hot or indifferent......idles lovely after around two minutes of driving it\'s just the initial first couple of minutes he won\'t idle at all unless the revs are held a smidgen higher with the accelerator pedal.

The choke part of the equation appears to be working okay so anyone got any ideas, I\'m getting fed up with having to heel and toe at traffic lights!

By the way.........1983.......Series 2.........12A everything standard apart from header and air pump removed.
i was going to post something tonight to ask if anyone else is having trouble in the cold!,
ive never had any of my RX7 run well in the cold, just like you say starts ok but the first 2 -4 minutes your never sure if it will cut out, the orgional chock set up is a bit rubbish IMO and i find it is no worse without a choke at all, i think it is just a part of the joy of owning one! the only other thing i can say is to check all you vac lines etc

Mark
Title: Cold Idle fun and games
Post by: captainbizzaro on January 26, 2008, 09:34:10 AM
Yeah it wouldn\'t bother me so much if I hadn\'t had it so good up till now-I used to be able to go and fire him up and that\'d be it-steady 2000 or so RPM for a few minutes then the auto choke would cut off but by then he\'d be warm enough to co-operate! I\'ll go look for anything glaringly obvious again today but nothing had changed when I last looked. I\'ll stare harder this time-maybe that\'ll work!:D
Title: Cold Idle fun and games
Post by: David Nock (RIP) on January 26, 2008, 12:51:27 PM
Gus ain\'t too good in the winter either - similar sort of thing. When I\'m driving I use the choke like an old style fully manual one and only really pull it out a bit for junctions etc. There should be a \'prop-open\' sort of device attached between the choke and the throttle quadrant on the carb to give it a few more revs - this works on Gus. The wife tends to use the auto choke, partly on, which might help with driving at junctions, on a slightly richer mixture than me.
Anyway, I would be looking at the \'what-props-the-revs-up-on-a-bit-of-choke-when-its-cold\' device.
Love to Neville as always.
Title: Cold Idle fun and games
Post by: captainbizzaro on January 26, 2008, 02:12:05 PM
Hi David,think you are pretty close to the mark there to be fair as the choke did used to effect the revs like it should but as I said-doesn\'t appear to any more. All that happens now when the choke is out is I end up smelling even more of petrol than I would normally! Will stare really hard at that side of the carb and await inspiration! Have looked in the Haynes manual but no mention in the index under \'W\' of \'what props the revs up on a bit of choke when it\'s cold\' device.:rollin  :Laugh  
 
Love back to Gus as always!
Title: Cold Idle fun and games
Post by: mpk490p on January 27, 2008, 08:50:09 AM
as i say ive never had one of these work (used to keep a small pair of molegrips in the car to use!!) but i think the box on the passenger side has a electronic magnet to hold the cable, not 100% as i dont have all that now! just follow the cable i suppose and see what does what!
Mark
Title: Cold Idle fun and games
Post by: David Nock (RIP) on January 27, 2008, 12:39:15 PM
Quote from: mpk490pas i say ive never had one of these work (used to keep a small pair of molegrips in the car to use!!) but i think the box on the passenger side has a electronic magnet to hold the cable, not 100% as i dont have all that now! just follow the cable i suppose and see what does what!
Mark
I think that\'s the hot start relay Mark, it works by pulling the throttle open slightly when the engine\'s hot. I\'m fairly sure the choke magnet unit is under the dash, operated by yet another function on the carb. How many blessed devices there were on the engine of what was otherwise a simple old car.
Title: Cold Idle fun and games
Post by: captainbizzaro on January 27, 2008, 04:38:44 PM
Just found this link on another thread.....
 
http://www.wankel.net/~krwright/files/manuals/1980_RX7_FSM/large/80RX7(4)Fuel_Inlet_Exh.pdf (http://www.wankel.net/~krwright/files/manuals/1980_RX7_FSM/large/80RX7(4)Fuel_Inlet_Exh.pdf)
 
Sorted!
Title: Cold Idle fun and games
Post by: captainbizzaro on January 27, 2008, 04:40:43 PM
Oh yeah,and question for David.....not including the back box how many silencers have you got in your system? I\'ve got two and that seems a bit OTT if you ask me? Or am I talking rubbish as per usual?!
Title: Cold Idle fun and games
Post by: mpk490p on January 27, 2008, 06:56:02 PM
i have 2 mid boxes and a rear (although the rear box is pretty much straight through)

Mark
Title: Cold Idle fun and games
Post by: captainbizzaro on January 27, 2008, 07:34:46 PM
Okay,so looking at that pdf workshop manual my first port of call should be the bimetal mechanism inside the air cleaner enclosure and this apparently is the idle compensator so that looks like a fair shout. I\'ll be doing that next weekend, when at the same time I\'ll be sorting the water leak that sprung today thanks to a dodgy jubilee clip.............and it goes on!:Tongue1 Oh the joys of FB ownership.:InLove
Title: Cold Idle fun and games
Post by: David Nock (RIP) on January 28, 2008, 11:20:09 AM
The system I use now only has 1 silencer and the back box. It\'s a \'Double S\' system.
Don\'t want to be a Jonah, but I can only see the idle compensator smoothing out hunting on cold running - as you will have noted it diverts hot air off the manifold into the air intake when cold. I don\'t see it propping the revs up.
With regard to water leaks, when checking the car, I always look across onto the top of the inlet manifold, behind the carb - look from the passenger\'s side- any coolant starting to pond up there means the \'O\' ring seals in the inlet manifold are starting to fail.
Title: Cold Idle fun and games
Post by: David Nock (RIP) on January 28, 2008, 11:37:22 AM
Not that I think your O rings are going, it\'s just something I thought of when I read your post. Plus I suppose the O rings could fail into the inlet manifold and you\'d never see it, although I\'ve only seen the first signs on the top of the manifold - Rambling along here guys, sorry!
Title: Cold Idle fun and games
Post by: captainbizzaro on January 28, 2008, 06:57:38 PM
LOL cheers for the input David! The only reason I\'m so confident that it is a jubilee clip is because I put it on in the first place-and I remember at the time thinking "this is way too bloomin big really" and lo and behold it\'s not up to it. That\'ll learn me.
 
Going back to your double S system-how loud is it with only the one mid silencer?
Title: Cold Idle fun and games
Post by: David Nock (RIP) on January 29, 2008, 12:12:39 PM
I\'M WRONG - Because it\'s whisper quiet I\'ve got out of my computer chair and looked under the car - there\'s 2 silencers plus the back box. I\'m sorry I didn\'t physically check before - just used my (obviously failing) memory.
It\'s neat though, all tucks up a fair way into the trans.tunnel - nothing hanging down. Double S are somewhere in the west country. They\'re on the net.
Actually, I didn\'t buy the system directly; I bought a scrapper for £350 a few years back and pulled it down. This stainless exhaust was one of the prizes! Fitted it to Gus in 2006: prior to that he was on standard Mazda exhaust.
Title: Cold Idle fun and games
Post by: captainbizzaro on January 31, 2008, 07:42:30 PM
Hmmm.....well I really like the look of the system thats on him at the mo-think it\'s standard issue with the twin tailpipe back box the only alteration being the header but trouble is because of all the popping and farting and flaming he does it seems to be taking it\'s toll on the first silencer. There is a definate tinny rattle from it now and it can\'t flowing that well if it\'s that blasted. Thought I might try one of those power flow franchises as we\'ve got one close and thought they could do something like the de-cat pipes they do for people because the rest of the system is fine-it\'s just whether or not it\'ll be loud once one of the silencers is removed.
Title: Cold Idle fun and games
Post by: mpk490p on January 31, 2008, 07:52:49 PM
Quote from: captainbizzaroHmmm.....well I really like the look of the system thats on him at the mo-think it\'s standard issue with the twin tailpipe back box the only alteration being the header but trouble is because of all the popping and farting and flaming he does it seems to be taking it\'s toll on the first silencer. There is a definate tinny rattle from it now and it can\'t flowing that well if it\'s that blasted. Thought I might try one of those power flow franchises as we\'ve got one close and thought they could do something like the de-cat pipes they do for people because the rest of the system is fine-it\'s just whether or not it\'ll be loud once one of the silencers is removed.
i have the 2 mid boxes in a stainless system and the rear box is pretty much straight through with a bung i can add but it is very loud, dont think i would have it with out the bung if i drive it everyday

Mark
Title: Cold Idle fun and games
Post by: captainbizzaro on January 31, 2008, 10:35:27 PM
Quote from: mpk490pi have the 2 mid boxes in a stainless system and the rear box is pretty much straight through with a bung i can add but it is very loud, dont think i would have it with out the bung if i drive it everyday
 
Mark

Is your system off the shelf Mark or was it built especially for you by one of those Powerflow type companies?
Title: Cold Idle fun and games
Post by: mpk490p on February 01, 2008, 07:43:36 AM
it was not custom for me, it came of another gen1 that was being broken, i belive it is the rotechniks produced stainess one, if you go through my build thread you will see the after market back box i fitted

Mark
Title: Cold Idle fun and games
Post by: Don Pamponi on February 02, 2008, 07:18:06 PM
Wow, I\'m away a while & everybody has named their cars!

Notice they are all male names.  I was thinking mine is more likely to get a female name co she\'s a bit of a be-atch. :Grrr

By the way Captain, I\'m promised that my car will be done in 2 weeks, so I\'ll be driving down with ur wheels if you still want em.

Meet me there or leave ££ with the other Tim.  Cheers
Title: Cold Idle fun and games
Post by: David Nock (RIP) on February 03, 2008, 11:26:29 AM
Nah... Gus was named when he came to us as an orphan in 1993. He was a little 7 year old FB then. Now he\'s a big strapping 23 year old.
He doesn\'t ride out with any girlie FB\'s though, so I\'m a bit worried.
However I certainly don\'t want him out with those drop-their-tops-quick as-a-flash convertible FC\'s and I think them rough-arsed FD lot are only one step up from Amy and Brittany.
So there\'s a name Don? Amy?
Title: Cold Idle fun and games
Post by: Don Pamponi on February 04, 2008, 07:52:46 PM
How bout Mandy the Mazda :Giggle
Title: Cold Idle fun and games
Post by: captainbizzaro on February 04, 2008, 10:25:17 PM
Rhianna the Rex?:flamed okay maybe not:Laugh
Title: Cold Idle fun and games
Post by: David Nock (RIP) on February 05, 2008, 11:17:16 AM
Donna Pamplemoose..... easy!