Idling Issue.- Plus General Queries.

[Tiger_kpt]

OK, will try to keep this simple.
I have a 1993 UK spec RX7 FD13.
 
Current modifications apart from subtle bodywork and wheels are as follows: -
 
Downpipe with pre-cat deleted (on car when purchased)
Racing Beat cat-back exhaust (on car when purchased)
HKS twin power ignition amplifier (I fitted this two weeks ago)
ARC super induction box (I fitted this last weekend)
 
I fitted the ARC box last weekend and ever since the engine idling when warm especially and during the warm up phase is a little lumpy. Engine seems a little rough running during the warm up cycle giving off a little vibration. And when warm the idle speed roams between the 500rpm - 850rpm range.
When driving though, the engine seems smooth, no issues.
 
For instance driving at 60mph, no issues. Brake, slow down and pull up to a halt in a lay-by and the engine and the engine dives initially down to 500rpm and idles roughly. Recovers quickly to around 650-700rpm and then continues to idle inconsistantly between 650-700rpm and 850rpm. The longer you leave it theugh... the smoother the idling becomes. A minute or so later the idle seems to stabilise as if the ECU has rebalanced something out.
 
Rev the engine or drive onwards, pull up to stop or just take the throttle off/clutch in and the engine goes through the same cycle.
 
This didn\'t seem to happen before I fit the ARC box (ran fine the week before after I fitted HKS igntion amp), or maybe it did, but not so obviously. Am just wondering if the installation of this box combined with the other engine mods could lead to this?
 
The car is running the standard 8-bit management, but I do have an Apexi PFC and Commander with base map ready to install. Will either install myself this weekend and run the car using the base-map... IS THIS SAFE TO DO SO? Or wait to have Pip at WGT install it and map it as have an appointment with him for alot of work in a week or two.
 
Do you think the new management would solve this issue on the base map? Or after a mapping session?
 
The other modifications to be done at WGT include: -
 
Apexi PFC + Commander (could do myself)
ACT streetlite clutch, flywheel and counterweight
Koyo radiator
Sard thermostat
Pettit Racing AST
Magnecor leads
NGK Plugs
Pettit Racing race cap
Greddy turbo timer
Greddy elbow with BOV flange
Greddy Type RS BOV kit
Centre section, straight through, de-cat OR high flow CAT
Loads of gauges and pods
 
Just wondering also... what the tell tale signs are of an imminient engine rebuild.
 
Also what are the tell tale signs of fouled spark plugs and worn ignition leads?
 
Thanks all.

[ash]

Hi Tiger_kpt

My Uk FD idles quite rough whilst it is cold but when its has warmed up it seems to settle to 850 - 900rpm. However, the car had been sitting around for about 1.5 years so i expect the reason for running rough on start up would be the plugs/leads. Im gonna change these myself - not too hard and give it a oil and filter change.

I would take out your plugs and check for abnormalities - a good plug will look clean, smooth and kind of chocolate brown.

HTH

[Tiger_kpt]

How hard is it to change the plugs and leads on these? How do you do it? How much of the ancillaries or engine components do you need to remove to be able to get to them? Their location? Any guides? And what sort of time to do so? How do you identify leading and trailing plugs on the engine?
 
My new set of NGK plugs have two of one sort of plug and two of another. I assume a different type for leading and another for trailing? Would do it myself but never done this on a rotary engine.
 
Also have Magnecor 8.5 racing leads to put on.
 
Do have a good mechanical knowledge and background though and would like to be able to do this myself with a little help.

[ash]

Well, i changed my plugs on Saturday. It was the first time i had done it and just did it off the cuff. Took me ages, i didnt remove anything except the nearside wheel. However, if your going to do the oil change i would advise doing it afterwards, alot less messy!! Started the car and it was running (im sure on 1 rotor) which i think lead to the car flooding!

So a quick search and i then read on here that someone used the mazda tool for this, i looked in my boot and there it was. So i removed 3 of teh 4 spark plugs and cleaned them off again within 15 minutes. I didnt remove anything and worked from the top of the engine down. Easy job, especially if you have small arms - not me, scratches to prove!

So, how hard to change the plugs - not hard at all. The leads - i dont know. You dont need tpo remove any of the ancillaries if you have the mazda tool. Location is nearside of engine near the centre below the oil filter. Time scale 30mins max. I had 9\'s NGK in all my chambers, i think you should have 7\'s and 9\' as Mazda re wrote the manual to read this. Leading plugs are the plugs on the bottom with the black lead these should be BUR9EQ (STANDARD SETUP), trailing have the blue ignition lead on them and these should be BUR7EQ, also standard set up.

You should give it a try, once you are stuck in then it will become easy.

Good luck

[Tiger_kpt]

Thanks for that write up Ash.
 
I\'m hearing conflicting info on the plugs.
Read: -
http://www.mazdarotaryclub.com/forums/showthread.php?t=36098
 
On the diagram given there where the plug positions are labelled 1-4. The top two plugs: 1 and 3 are the leading and the bottom two: 2 and 4 are the trailing.
 
Apparently according to memski BUR7EQP are leading? Colder plugs for trailing?
 
But I would have thought that BUR7EQP were colder than BUR9EQP? Or is it the other way round?
 
How did your car run after the plug change? Mine is really lumpy at idle with foot off of the gas. Jumpy revs and a bit of vibration given off.

[probedb]

You can run all 9s. Mine came back from a service with Pip with all 9s in it.

[ash]

No worries kpt

From the factory service manual this is what it has a picture of:



In mine i had 9\'s all round, so i will be changing to 7\'s in the leading side when i have some more cash!

I cant remember which way round the numbers go in terms of being hotter or colder??

My car was running not well when cold, i cleaned the plugs only and i dont think one of the leads was reconnected properly, so it was effectivley only running one rotor on the leading plug. Which i think flooded it. So, will be leaving it for a few days before i start it again. I have a lot of vibration from my car - i have a new diff mount with bushes on its way and may purchase a set of engine bushes/mounts too. I think this will cure the problem

[Illyont]

I run 7 and 9, but next time I change I\'m going for all 9. Idle is mint. Doesn\'t move at all. Dead steady.
 
But it was that way before changing plugs too, so.

[Tiger_kpt]

Well I have two 9\'s and two 7\'s. So which is which?
 
And are the leading the top two plugs? And trailing the bottom two plugs on the engine?

[ash]

Otherway round according to the Manual, and the leads on my car (Blue) the top two plugs are Trailing so should be 9\'s and the bottom are leading so should be 7\'s. i cant say that 7s and 9\' make a difference than 9\'s all round but Mazda sent out a service bulletin to rewrite the manual and change the it to read use 7\'s and 9\'s?

[ro284]

http://i15.photobucket.com/albums/a3...g?t=1174897799

Not wanting to confuse things further,  but i believe this has been mentioned before that Mazda got these plugs marked the wrong way round in the manual, as i understand it the 7s (if you use them,) are trailing and go in both the top two plug holes, Most guys. i do, seem to find 9s all round to be the best, (less chance of flooding, confusion, etc.) i.m sure someone more knowledgeable will be along to answer your queries shortly,
Bob

[ash]

Not wanting to confuse things further,  but i believe this has been mentioned before that Mazda got these plugs marked the wrong way round in the manual, as i understand it the 7s (if you use them,) are trailing and go in both the top two plug holes, Most guys. i do, seem to find 9s all round to be the best, (less chance of flooding, confusion, etc.) i.m sure someone more knowledgeable will be along to answer your queries shortly,
Bob

Definately confussed :3Confused

I have the blue ignition leads nearer the top of the engine. So this is correct but the plugs should be 9\'s at the top and 7\'s bottom if you go this route. Fortunately i have 9\'s all round.

If RO284 is correct, sorry for confusing anyone here - but im gonna blame Mazda!

[Tiger_kpt]

So 7\'s are trailing and go in the bottom two plug ports?
 
9\'s are leading and go in the top to plug ports?
 
Just out of interest which way (as you\'re sat at the steering wheel) do the rotors spin? In a clockwise direction? Or an anti-clockwise direction?
If I knew this, then I could define which slots are leading and which are trailing.
 
Then all we need to know is whether the 7\'s are suitable for trailing or leading. 9\'s would be obvious then.

[Tiger_kpt]

OK. Just an update. Did some online research and came up with this: -
 
The leading plugs are the lower two plugs ports.
The trailing plugs are the top two plug ports.
 
Best way to remember is: -
 
TT - Trailing Top
LL - Leading Lower
 
Trailing plugs have two blue rings around the ceramic.
Trailing leads have blue rubber caps.
 
Leading coils are in the middle of the engine.
Trailing coils are either side. One towards battery and one towards firewall.
 
On the leading ignitor you\'ll see L1 and L2.
1 means front rotor.
2 means rear rotor.
 
#1 trailing coil is the one nearest the battery.
#2 trailing coil is the one nearest the firewall.
 
#1 leading wire on leading coil is top one.
#2 leading wire on leading coil is bottom one.
 
So on the diagram on the link to the above thread...
1 = rear rotor trailing plug
2 = rear rotor leading plug
3 = front rotor trailing plug
4 = front rotor leading plug
 
From that... the rotors... when sat in the drivers seat looking forward at them... spin in a clockwise motion.
 
Now all I need to know is whether NGK BUR7EQP are used as leading or trailing rather than 9\'s all round. Anyone know this?

[Tiger_kpt]

When replacing ignition wires from the top of the engine bay... does anyone know what you have to remove in terms of ancillaries and engine components to get to them easily to take out the old and replace with the new? Will do these the same time as the plugs.