Cold Idle fun and games

[captainbizzaro]

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.

[mpk490p]

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.

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

[captainbizzaro]

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

[David Nock (RIP)]

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.

[captainbizzaro]

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!

[mpk490p]

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

[David Nock (RIP)]

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

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.

[captainbizzaro]

Just found this link on another thread.....
 
http://www.wankel.net/~krwright/files/manuals/1980_RX7_FSM/large/80RX7(4)Fuel_Inlet_Exh.pdf
 
Sorted!

[captainbizzaro]

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?!

[mpk490p]

i have 2 mid boxes and a rear (although the rear box is pretty much straight through)

Mark

[captainbizzaro]

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

[David Nock (RIP)]

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.

[David Nock (RIP)]

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!

[captainbizzaro]

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?

[David Nock (RIP)]

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.